You searched for subject:(Pump AND probe).
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Vanderbilt University
1.
-3410-7263.
Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene.
Degree: PhD, Physics, 2020, Vanderbilt University
URL: http://hdl.handle.net/1803/16384 
► In this dissertation we seek to present a comprehensive fluence and wavelength dependent ultrafast pump-probe transmission study of graphene supported on a soda-lime glass substrate…
(more)
▼ In this dissertation we seek to present a comprehensive fluence and wavelength dependent ultrafast
pump-
probe transmission study of graphene supported on a soda-lime glass substrate for a range of
pump fluences that enable us to observe both decreased and enhanced
probe transmission regimes on a femtosecond timescale. Specifically, we study the crossover region from decreased to enhanced
probe transmission, which occurs at an intermediate threshold
pump fluence. At intermediate threshold
pump fluences we observe an order of magnitude decrease in the relaxation time constant of the differential transmission as compared to higher and lower
pump fluences. This optical effect can be explained by equal contributions of inter- and intraband transitions with opposite signs to the transient optical conductivity of graphene at intermediate
pump fluences. Moreover, the intermediate threshold
pump fluence is shown to increase with decreasing
probe energy, which is in agreement with the theoretical model. Furthermore, we show that the relaxation time of the electronic temperature increases monotonically over the range of fluences studied. Comparison with the measured relaxation times of the differential transmission implies that
pump fluence greatly modifies time-dependent optical properties, while the electron and phonon relaxation processes remain unaffected. In perspective, this work is of importance to graphene- based opto-electronic applications such as light modulators.
Advisors/Committee Members: Tolk, Norman H (advisor).
Subjects/Keywords: Ultrafast pump-probe dynamics; graphene
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APA (6th Edition):
-3410-7263. (2020). Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/16384
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Chicago Manual of Style (16th Edition):
-3410-7263. “Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene.” 2020. Doctoral Dissertation, Vanderbilt University. Accessed March 06, 2021.
http://hdl.handle.net/1803/16384.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
MLA Handbook (7th Edition):
-3410-7263. “Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene.” 2020. Web. 06 Mar 2021.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Vancouver:
-3410-7263. Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene. [Internet] [Doctoral dissertation]. Vanderbilt University; 2020. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1803/16384.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Council of Science Editors:
-3410-7263. Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene. [Doctoral Dissertation]. Vanderbilt University; 2020. Available from: http://hdl.handle.net/1803/16384
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
2.
Boyd, Kevin.
Novel Free-Carrier Pump/Probe Techniques for the Characterization of Silicon.
Degree: PhD, 2018, McMaster University
URL: http://hdl.handle.net/11375/24148
► Two novel pump/probe techniques have been developed for measuring the recombination lifetime in crystalline silicon wafers. The first technique, single-beam pump/probe, uses one laser as…
(more)
▼ Two novel pump/probe techniques have been developed for measuring the recombination lifetime in crystalline silicon wafers. The first technique, single-beam pump/probe, uses one laser as both pump and probe. The second technique, quasi-steady state free-carrier absorption, measures lifetime under quasi-steady state conditions. These techniques are supported by a general mathematical model that predicts the experimental signal accounting for the 3D charge-carrier transport and recombination within the semiconductor. The predictions of the model are validated experimentally, and quantitative agreement is found between the model and experimental results for both techniques. The recombination lifetime measured by these techniques is verified independently using a standard pump/probe method, and the results are in agreement with this work. Single-beam pump/probe is a first-time demonstration of a technique capable of measuring lifetime in silicon using a single laser beam. It dramatically simplifies traditional pump/probe measurements by completely eliminating the second laser beam. QSS-FCA is the first quasi-steady state technique that can be calibrated in situ without the requirement of a calibrated reference wafer. The calibration constant is the free-carrier absorption cross section of silicon, which is a material constant. QSS-FCA is able to measure this cross section to a higher precision than what has been reported in the literature. Precise measurement of this constant opens up the possibility of studying more fundamental physics of silicon using QSS-FCA.
Thesis
Doctor of Philosophy (PhD)
Advisors/Committee Members: Kleiman, Rafael, Engineering Physics.
Subjects/Keywords: lifetime spectroscopy; recombination lifetime; pump/probe; silicon
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APA (6th Edition):
Boyd, K. (2018). Novel Free-Carrier Pump/Probe Techniques for the Characterization of Silicon. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/24148
Chicago Manual of Style (16th Edition):
Boyd, Kevin. “Novel Free-Carrier Pump/Probe Techniques for the Characterization of Silicon.” 2018. Doctoral Dissertation, McMaster University. Accessed March 06, 2021.
http://hdl.handle.net/11375/24148.
MLA Handbook (7th Edition):
Boyd, Kevin. “Novel Free-Carrier Pump/Probe Techniques for the Characterization of Silicon.” 2018. Web. 06 Mar 2021.
Vancouver:
Boyd K. Novel Free-Carrier Pump/Probe Techniques for the Characterization of Silicon. [Internet] [Doctoral dissertation]. McMaster University; 2018. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/11375/24148.
Council of Science Editors:
Boyd K. Novel Free-Carrier Pump/Probe Techniques for the Characterization of Silicon. [Doctoral Dissertation]. McMaster University; 2018. Available from: http://hdl.handle.net/11375/24148
Purdue University
3.
Yao, Qiaomu.
ULTRAFAST ELECTRON-PHONON COUPLING AT THE METAL-DIELECTRIC INTERFACE.
Degree: MSME, Mechanical Engineering, 2015, Purdue University
URL: https://docs.lib.purdue.edu/open_access_theses/1087
► The pump-probe technique is an ultrafast spectroscopy method of detecting the dynamics of energy carriers such as electrons, phonons, and holes with transient thermal reflectance…
(more)
▼ The
pump-
probe technique is an ultrafast spectroscopy method of detecting the dynamics of energy carriers such as electrons, phonons, and holes with transient thermal reflectance measurement. A laser beam is divided into a
pump beam and
probe beam with different wavelength or polarization and time delay. According to the transient reflectance result, this method could be applied to investigate the interaction between electron-phonon and electron-electron coupling with a high temporal resolution on the order of 10 femtoseconds.
Advisors/Committee Members: Xianfan Xu, Xiulin Ruan, Timothy S. Fisher.
Subjects/Keywords: Heat Transfer; Interface; Nanoscale; Pump and probe
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APA (6th Edition):
Yao, Q. (2015). ULTRAFAST ELECTRON-PHONON COUPLING AT THE METAL-DIELECTRIC INTERFACE. (Thesis). Purdue University. Retrieved from https://docs.lib.purdue.edu/open_access_theses/1087
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Yao, Qiaomu. “ULTRAFAST ELECTRON-PHONON COUPLING AT THE METAL-DIELECTRIC INTERFACE.” 2015. Thesis, Purdue University. Accessed March 06, 2021.
https://docs.lib.purdue.edu/open_access_theses/1087.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Yao, Qiaomu. “ULTRAFAST ELECTRON-PHONON COUPLING AT THE METAL-DIELECTRIC INTERFACE.” 2015. Web. 06 Mar 2021.
Vancouver:
Yao Q. ULTRAFAST ELECTRON-PHONON COUPLING AT THE METAL-DIELECTRIC INTERFACE. [Internet] [Thesis]. Purdue University; 2015. [cited 2021 Mar 06].
Available from: https://docs.lib.purdue.edu/open_access_theses/1087.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Yao Q. ULTRAFAST ELECTRON-PHONON COUPLING AT THE METAL-DIELECTRIC INTERFACE. [Thesis]. Purdue University; 2015. Available from: https://docs.lib.purdue.edu/open_access_theses/1087
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Minnesota
4.
Goff, Philip.
Exciton Dynamics in Organic Semiconducting Materials.
Degree: PhD, Chemistry, 2017, University of Minnesota
URL: http://hdl.handle.net/11299/188833
► World energy consumption is projected to rise dramatically over the next three decades. Presently, over 80% of worldwide energy consumption is derived from nonrenewable sources.…
(more)
▼ World energy consumption is projected to rise dramatically over the next three decades. Presently, over 80% of worldwide energy consumption is derived from nonrenewable sources. In order to meet these demands, increased utilization of solar energy will be required. Organic semiconducting materials are an attractive alternative to the traditional crystalline silicon devices which at present dominate the photovoltaic market. They possess a number of material and physical processes which may ultimately prove for photogeneration of electricity at a cost competitive with conventional nonrenewable fuel sources. However, the power conversion efficiencies of these devices at present limits their widespread adoption. In order to improve their efficiencies, it is important to understand the relationship between chemical and physical characteristics of the molcules with the exhibited excited state photophysics. In this dissertation, the excited state properties of various organic semiconducting materials, such as polymers and small molecules, will be examined. First, in Chapter 3 a series of statistical donor/acceptor copolymers were generated where the monomer unit composition was tuned in order to adjust the absorption properties of the polymer. Ultrafast pump-probe spectroscopy was employed to characterize the effect that changing polymer composition has on the exciton lifetime within these materials. It was found that by tuning the composition of the monomer units, the lifetime could be extended nearly 30 times over that of either neat donor or neat acceptor monomer units. Moreover, the lifetime reached a maximum at a ratio of approximately 1:4 donor to acceptor monomer units, suggesting that fine-tuning the ratio of the two may provide enhancements in OPV performance. In Chapters 4 and 5, ultrafast pump-probe spectroscopy was used to characterize exciton transport in thin films of Subphthalocyanine and Subnaphthalocyanine. Adjusting the film composition was found to have a substantial influence on the exciton diffusion length in the films. Importantly, exciton-annihilation induced heating of the films resulted in the manifestation of thermal signatures in the transient spectra. These signatures were not previously well appreciated in literature as manifesting on a sub-nanosecond timescale, and have been potentially erroneously assigned as electronic signatures from excited state species. A method is proposed to isolate these thermal signatures from the excitonic signatures, yielding accurate exciton decay dynamics. Finally, the excited state dynamics of a series of novel boron dipyrromethane derivatives will be investigated in Chapter 6. Particular attention will be made as to whether there is a potential for these materials to spontaneously form a spontaneously self-assembled supramolecular complex with fullerene in solution. The formation of such complexes is of considerable interest, however the results herein suggest that many of the previously reported complexes may actually be misinterpretation of photoluminescence…
Subjects/Keywords: exciton; organic photovoltaic; pump-probe; transient absorption
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APA (6th Edition):
Goff, P. (2017). Exciton Dynamics in Organic Semiconducting Materials. (Doctoral Dissertation). University of Minnesota. Retrieved from http://hdl.handle.net/11299/188833
Chicago Manual of Style (16th Edition):
Goff, Philip. “Exciton Dynamics in Organic Semiconducting Materials.” 2017. Doctoral Dissertation, University of Minnesota. Accessed March 06, 2021.
http://hdl.handle.net/11299/188833.
MLA Handbook (7th Edition):
Goff, Philip. “Exciton Dynamics in Organic Semiconducting Materials.” 2017. Web. 06 Mar 2021.
Vancouver:
Goff P. Exciton Dynamics in Organic Semiconducting Materials. [Internet] [Doctoral dissertation]. University of Minnesota; 2017. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/11299/188833.
Council of Science Editors:
Goff P. Exciton Dynamics in Organic Semiconducting Materials. [Doctoral Dissertation]. University of Minnesota; 2017. Available from: http://hdl.handle.net/11299/188833
Boston University
5.
Shah, Parth Prashant.
Ultrafast infrared spectroscopy of nitrous oxide as a probe in salt water and supercritical sulfur hexafluoride.
Degree: PhD, Chemistry, 2019, Boston University
URL: http://hdl.handle.net/2144/39599
► Different forms of ultrafast spectroscopy, namely two-dimensional infrared spectroscopy (2DIR) and pump probe spectroscopy, are used to determine spectral diffusion, vibrational energy relaxation (VER), and…
(more)
▼ Different forms of ultrafast spectroscopy, namely two-dimensional infrared spectroscopy (2DIR) and
pump probe spectroscopy, are used to determine spectral diffusion, vibrational energy relaxation (VER), and the dynamics of the solvent environments around
probe molecules in various solutions. Supercritical fluids are valuable as potential green solvents, so it is important to explore and understand these dynamical processes in these solvents.
Ultrafast
pump-
probe spectroscopy was used to investigate the VER of nitrous oxide (N2O) dissolved in water with different concentrations of ionic salts. Chloride salts of different cations were used to determine changes in VER and reorientation anisotropy decay (R(t)) of N2O as a function of cation. These rates were found to be consistent with the Hoffmeister series trend of structure makers and structure breakers and showed evidence of cation effects on the water hydrogen bonding network beyond the first solvation shell.
Ultrafast two-dimensional infrared (2DIR) spectroscopy of N2O’s asymmetric stretching (√3) mode in sulfur hexafluoride (SF6) gas resulted in rovibrational spectral lineshapes which show complicated behavior compared to 2DIR lineshapes of traditional condensed phase samples. There is an additional antidiagonal features which appears in the spectra of dense state points. These observed spectra indicate that there is a quasi-free rotor population, which is captured by a model including all 36 possible rovibrational density matrix pathways originating from a specific J-level. The decays of these 2DIR spectral features can be attributed to the N2O and SF6 collisions, roughly decaying on the scale of one to two collisions.
Further 2DIR spectra were taken of the system in the supercritical regime of SF6. Even at these supercritical state points, the frequency correlation decay is still on the order of one to two collisions and confirm that an independent binary collision model is sufficient for describing rotational relaxation in these SCF solutions.
Pump-
probe spectroscopic measurements offer N2O √3 vibrational relaxation timescales ~10 times slower than spectral diffusion dynamics attributable to rotational relaxation. The growth of a “Q”-type 1 ← 0 √3 transition feature in the null region of the mid-IR spectrum is observed with increasing fluid density. Analysis based on these 2DIR results indicates this feature is a sign of liquid-like character in these solutions and that both hindered and quasi-free rotors exist in the same solvent environment in the dense and supercritical N2O – SF6 solution. This experimental methodology enables future lineshape studies on the effects of solvent interactions on vibrational and rotational relaxation rates, dynamics from non-equilibrium states at high temperature and pressures, and critical point solvation dynamics.
Advisors/Committee Members: Ziegler, Lawrence D. (advisor), Erramilli, Shyamsunder (advisor).
Subjects/Keywords: Physical chemistry; 2DIR; Laser; Pump-probe
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APA ·
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APA (6th Edition):
Shah, P. P. (2019). Ultrafast infrared spectroscopy of nitrous oxide as a probe in salt water and supercritical sulfur hexafluoride. (Doctoral Dissertation). Boston University. Retrieved from http://hdl.handle.net/2144/39599
Chicago Manual of Style (16th Edition):
Shah, Parth Prashant. “Ultrafast infrared spectroscopy of nitrous oxide as a probe in salt water and supercritical sulfur hexafluoride.” 2019. Doctoral Dissertation, Boston University. Accessed March 06, 2021.
http://hdl.handle.net/2144/39599.
MLA Handbook (7th Edition):
Shah, Parth Prashant. “Ultrafast infrared spectroscopy of nitrous oxide as a probe in salt water and supercritical sulfur hexafluoride.” 2019. Web. 06 Mar 2021.
Vancouver:
Shah PP. Ultrafast infrared spectroscopy of nitrous oxide as a probe in salt water and supercritical sulfur hexafluoride. [Internet] [Doctoral dissertation]. Boston University; 2019. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2144/39599.
Council of Science Editors:
Shah PP. Ultrafast infrared spectroscopy of nitrous oxide as a probe in salt water and supercritical sulfur hexafluoride. [Doctoral Dissertation]. Boston University; 2019. Available from: http://hdl.handle.net/2144/39599
Louisiana State University
6.
Khoury, Rami Anthony.
Ultrafast and Nonlinear Spectroscopy of Nanomaterials.
Degree: PhD, Physical Chemistry, 2018, Louisiana State University
URL: https://digitalcommons.lsu.edu/gradschool_dissertations/4682
► Ultrafast and nonlinear spectroscopies are implemented in the investigation of excited-state dynamics and structural properties of materials and nanomaterials. In the first study, the…
(more)
▼ Ultrafast and nonlinear spectroscopies are implemented in the investigation of excited-state dynamics and structural properties of materials and nanomaterials. In the first study, the excited-state dynamics of size-dependent colloidal TiO2-Au nanocomposites are investigated using ultrafast transient absorption spectroscopy. The dynamics corresponding to the plasmon depletion band are characterized by electron-phonon and phonon-phonon coupling lifetimes that are observed to be independent of the gold nanocluster shell thickness. The excited-state dynamics corresponding to the interband transition of gold is also spectrally overlapped with the interfacial electron transfer lifetime, which is shown to decrease as the nanocluster shell thickness increases. In the second study, in-situ second harmonic generation (SHG), a nonlinear spectroscopic technique, is coupled with extinction spectroscopy to monitor the growth of colloidal gold nanoparticles in real time. The in-situ SHG results capture an early stage of the growth process where a large enhancement in the SHG is observed due to the formation of plasmonic hot spots attributed to a rough and uneven nanoparticle surface. In a third project, the ultrafast carrier dynamics of self-assembled La1-xSrxTiO3-δ (LMSO) is studied using ultrafast reflectivity experiments. The measured long-lived phonon-phonon coupling lifetime for the oxygen deficient LSMO thin film indicates that the phonons are the major energy carrier in the system. Residual oscillations of two distinct phonon frequencies are also observed and are superimposed on a biexponential decay. Both oscillatory signals are fit with an exponentially damping sine function in which both frequency and damping times are obtained. In a fourth project, our ultrafast reflectivity setup is modified with an added microscopy component for our work with the Consortium for Innovation in Manufacturing and Materials (CIMM) to investigate heating and melting dynamics of metals, semiconductors, and metal alloys. Finally, in the last portion of this dissertation, electronic sum-frequency generation spectroscopy is utilized to study the azimuthal angular dependence in α-quartz (0001). This dissertation describes the versatility of these ultrafast and nonlinear spectroscopic techniques through fundamental research on different types of materials and nanomaterials in colloidal suspension and at surfaces.
Subjects/Keywords: ultrafast; nonlinear; plasmonics; nanoparticles; pump-probe; reflectivity
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APA (6th Edition):
Khoury, R. A. (2018). Ultrafast and Nonlinear Spectroscopy of Nanomaterials. (Doctoral Dissertation). Louisiana State University. Retrieved from https://digitalcommons.lsu.edu/gradschool_dissertations/4682
Chicago Manual of Style (16th Edition):
Khoury, Rami Anthony. “Ultrafast and Nonlinear Spectroscopy of Nanomaterials.” 2018. Doctoral Dissertation, Louisiana State University. Accessed March 06, 2021.
https://digitalcommons.lsu.edu/gradschool_dissertations/4682.
MLA Handbook (7th Edition):
Khoury, Rami Anthony. “Ultrafast and Nonlinear Spectroscopy of Nanomaterials.” 2018. Web. 06 Mar 2021.
Vancouver:
Khoury RA. Ultrafast and Nonlinear Spectroscopy of Nanomaterials. [Internet] [Doctoral dissertation]. Louisiana State University; 2018. [cited 2021 Mar 06].
Available from: https://digitalcommons.lsu.edu/gradschool_dissertations/4682.
Council of Science Editors:
Khoury RA. Ultrafast and Nonlinear Spectroscopy of Nanomaterials. [Doctoral Dissertation]. Louisiana State University; 2018. Available from: https://digitalcommons.lsu.edu/gradschool_dissertations/4682
McMaster University
7.
Gao, Shuaiwen.
Carrier Lifetime and Diffusion Measurement using Free-carrier Absorption Imaging.
Degree: MASc, 2020, McMaster University
URL: http://hdl.handle.net/11375/25815
► At the moment, when energy and environmental issues are of concerned in our society, photovoltaic technology has received tremendous development and demand. Because carrier lifetime…
(more)
▼ At the moment, when energy and environmental issues are of concerned in our society, photovoltaic technology has received tremendous development and demand. Because carrier lifetime and diffusion coefficient are the important indicators to determine the recombination level, which influences the efficiency of solar cells to a large extent, they are regarded as key in choosing solar cell materials. A technique for effective lifetime measurement, modulated free-carrier absorption (FCA), can extract lifetime and diffusion coefficient simultaneously, which is supported by a general mathematical model that predicts the experimental signal accounting for the 3-dimensional (3D) charge-carrier transport and recombination within the semiconductor. A single mode 1064 nm laser modulated by an EO modulator is used as the pump and a 2050 nm modulated LED is used as probe in this experiment as the pump/probe parts. An IR camera detects the frequency-domain diffusion image from the tested silicon sample at the tested frequency range between 1 kHz to 200 kHz and the lifetime can be extracted by frequency-domain free-carrier concentration equation, which is a Lorentzian model. By simulating the diffusion data from the camera with the 3D free-carrier absorption model, we can extract lifetime and diffusion coefficient simultaneously. The fitted lifetime from frequency-domain free-carrier absorption equation is 33.5 ± 1.3 μs, and the fitted lifetime from this 3D FCA model is 32.8 ± 1.5 μs, which match to within the error bars. The fitted diffusion coefficient from this 3D FCA model is 15.6 ± 0.7 cm2/s, which agrees with the theoretical value of 16 cm2/s for silicon. Good quantitative agreement is found among the model, experimental data, and theory.
Thesis
Master of Applied Science (MASc)
Advisors/Committee Members: Kleiman, Rafael, Engineering Physics.
Subjects/Keywords: lifetime spectroscopy; recombination lifetime; pump/probe; silicon
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APA ·
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APA (6th Edition):
Gao, S. (2020). Carrier Lifetime and Diffusion Measurement using Free-carrier Absorption Imaging. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/25815
Chicago Manual of Style (16th Edition):
Gao, Shuaiwen. “Carrier Lifetime and Diffusion Measurement using Free-carrier Absorption Imaging.” 2020. Masters Thesis, McMaster University. Accessed March 06, 2021.
http://hdl.handle.net/11375/25815.
MLA Handbook (7th Edition):
Gao, Shuaiwen. “Carrier Lifetime and Diffusion Measurement using Free-carrier Absorption Imaging.” 2020. Web. 06 Mar 2021.
Vancouver:
Gao S. Carrier Lifetime and Diffusion Measurement using Free-carrier Absorption Imaging. [Internet] [Masters thesis]. McMaster University; 2020. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/11375/25815.
Council of Science Editors:
Gao S. Carrier Lifetime and Diffusion Measurement using Free-carrier Absorption Imaging. [Masters Thesis]. McMaster University; 2020. Available from: http://hdl.handle.net/11375/25815
NSYSU
8.
Wang, Ming-Sung.
The carrier relaxation of Si doped InN thin films.
Degree: Master, Physics, 2011, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0823111-190150
► Ultrafast time-resolved pump-probe (TRPP) apparatus has been applied to study the carrier dynamics of Si-doped InN thin films grown buffer by molecular beam expitaxy with…
(more)
▼ Ultrafast time-resolved
pump-
probe (TRPP) apparatus has been applied to study the carrier dynamics of Si-doped InN thin films grown buffer by molecular beam expitaxy with and without a low-temperature growth GaN buffer layer. The peak of the PL has been found to increase from 0.7 to 0.8 eV with the back ground density. The total decay rates as a function of the delay time were obtained by the density-dependent TRPP peak intensity and the time-resolved TRPP signals. The total decay rates were interpreted as the sum of radiative and nonradiative recombination. The Shockley-Read-Hall decay rate derived from the TRPP signal at low photoexccitation density was found to increase with the doping density. At low concentration, the Auger recombination is not effective. The dominant recombination mechanism at room temperature is the Shockely-Read-Hall recombination.
Advisors/Committee Members: Der-Jun Jang (committee member), Chie-Tong Kuo (chair), Yung-Sung Chen (chair), Meng-En Lee (chair), Li-Wei Tu (chair).
Subjects/Keywords: InN; time-resolved pump-probe; Si-doped InN; decay rate; PL
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APA ·
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Manager
APA (6th Edition):
Wang, M. (2011). The carrier relaxation of Si doped InN thin films. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0823111-190150
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wang, Ming-Sung. “The carrier relaxation of Si doped InN thin films.” 2011. Thesis, NSYSU. Accessed March 06, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0823111-190150.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wang, Ming-Sung. “The carrier relaxation of Si doped InN thin films.” 2011. Web. 06 Mar 2021.
Vancouver:
Wang M. The carrier relaxation of Si doped InN thin films. [Internet] [Thesis]. NSYSU; 2011. [cited 2021 Mar 06].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0823111-190150.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wang M. The carrier relaxation of Si doped InN thin films. [Thesis]. NSYSU; 2011. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0823111-190150
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
NSYSU
9.
Wang, Fu-Yun.
The Study of Carrier Dynamics in Multi-Stacked InAs/GaAs Quantum Dots.
Degree: Master, Physics, 2012, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0808112-114247
► This paper is using the Time-resolved Pump-Probe spectroscopy to study the quantum dots samples. The samples are InAs/GaAs multi-stacked quantum dots that with different spacer…
(more)
▼ This paper is using the Time-resolved
Pump-
Probe spectroscopy to study the quantum dots samples. The samples are InAs/GaAs multi-stacked quantum dots that with different spacer layer (10~30 nm). The stain between the InAs quantum dots and GaAs spacer layer that makes the valence band to split into heavy-hole and light-hole energy band. From the photoluminescence (PL), we see the heavy-hole and light-hole energy band are blue shift in InAs quantum dot, when the GaAs spacer layer decrease. We use the optic property of
Pump-
Probe spectroscopy of the change in the refraction index În to investigate the shift of heavy-hole energy band, when the GaAs spacer layer decrease. We see the heavy-hole energy band of GaAs is blue shift when the GaAs spacer layer decrease. When we change the
pump energy, the TRPP spectroscopy signal will change from positive to negative. This is the band-filling effect changes the refraction index În , when the energy close to the GaAs heavy hole energy state. When the energy is above the GaAs heavy hole energy state, the TRPP signal is positive. When the excited carrier density decrease and the delay time increase, TRPP signal will change the positive value to negative value. These are band-gap renormalization and free-carrier absorption effect change the refraction index În, when the carrier density decrease.
Advisors/Committee Members: Li-Wei Tu (chair), Der-Jun Jang (committee member), Meng-En Lee (chair), Yung-Sung Chen (chair), Tsu-Chiang Yen (chair).
Subjects/Keywords: multi-stacked; GaAs; InAs; quantum dot; dynamics; pump-probe
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APA (6th Edition):
Wang, F. (2012). The Study of Carrier Dynamics in Multi-Stacked InAs/GaAs Quantum Dots. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0808112-114247
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wang, Fu-Yun. “The Study of Carrier Dynamics in Multi-Stacked InAs/GaAs Quantum Dots.” 2012. Thesis, NSYSU. Accessed March 06, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0808112-114247.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wang, Fu-Yun. “The Study of Carrier Dynamics in Multi-Stacked InAs/GaAs Quantum Dots.” 2012. Web. 06 Mar 2021.
Vancouver:
Wang F. The Study of Carrier Dynamics in Multi-Stacked InAs/GaAs Quantum Dots. [Internet] [Thesis]. NSYSU; 2012. [cited 2021 Mar 06].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0808112-114247.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wang F. The Study of Carrier Dynamics in Multi-Stacked InAs/GaAs Quantum Dots. [Thesis]. NSYSU; 2012. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0808112-114247
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Ruhr Universität Bochum
10.
Niermann, Benedikt.
The role of metastable atoms in radio-frequency
micro-plasma jet discharges operated at atmospheric
pressure.
Degree: 2012, Ruhr Universität Bochum
URL: http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-34543
► Laser- (TDLAS) und Breitband-Spektroskopie wurden genutzt, um räumlich und zeitlich hoch aufgelöste Dichteprofile von metastbabilen Edelgasatomen in RF Mikroplasma-Entladungen unter Atmosphärendruck zu messen. Zwei unterschiedliche…
(more)
▼ Laser- (TDLAS) und Breitband-Spektroskopie wurden
genutzt, um räumlich und zeitlich hoch aufgelöste Dichteprofile von
metastbabilen Edelgasatomen in RF Mikroplasma-Entladungen unter
Atmosphärendruck zu messen. Zwei unterschiedliche
Elektroden-Konfigurationen wurden eingesetzt: ein konventionelles
Parallelplatten-System, betrieben als stabile alpha- Mode
Entladung, und eine koaxiale Geometrie mit einem filamentierten
Plasma im expandierenden Effluenten. Um die Entladungsdynamik
vollständig zu verstehen, wurde eine breite Parameter-Studie, vor
allem in den Bereichen Leistungseinkopplung, Elektrodenabstand,
Gasmischung, Gasfluss und Verunreinigungsbeimischung durchgeführt.
Die fundamentale Verhaltensweise der Entladung und die Grenzen des
stabilen Betriebsbereichs wurden untersucht. Darüber hinaus werden
in der Arbeit die Dynamik von Plasma Durchbruch und Kollaps sowie
deren Manipulation bei Wechselwirkung mit starken Laser Feldern
diskutiert.
Advisors/Committee Members: Physik und Astronomie.
Subjects/Keywords: Plasma; Angeregter Zustand; Absorptionsspektroskopie;
Filament; Pump-Probe-Technik
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APA (6th Edition):
Niermann, B. (2012). The role of metastable atoms in radio-frequency
micro-plasma jet discharges operated at atmospheric
pressure. (Thesis). Ruhr Universität Bochum. Retrieved from http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-34543
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Niermann, Benedikt. “The role of metastable atoms in radio-frequency
micro-plasma jet discharges operated at atmospheric
pressure.” 2012. Thesis, Ruhr Universität Bochum. Accessed March 06, 2021.
http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-34543.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Niermann, Benedikt. “The role of metastable atoms in radio-frequency
micro-plasma jet discharges operated at atmospheric
pressure.” 2012. Web. 06 Mar 2021.
Vancouver:
Niermann B. The role of metastable atoms in radio-frequency
micro-plasma jet discharges operated at atmospheric
pressure. [Internet] [Thesis]. Ruhr Universität Bochum; 2012. [cited 2021 Mar 06].
Available from: http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-34543.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Niermann B. The role of metastable atoms in radio-frequency
micro-plasma jet discharges operated at atmospheric
pressure. [Thesis]. Ruhr Universität Bochum; 2012. Available from: http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-34543
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Universiteit Utrecht
11.
Clarijs, J.
Femtosecond laser nano-ablation of glass surfaces and their self-scattering effects.
Degree: 2016, Universiteit Utrecht
URL: http://dspace.library.uu.nl:8080/handle/1874/328402
► In this thesis, the interaction between a femtosecond laser and glasses in the ablation regime is studied. A pulsed femtosecond laser setup allows for surface…
(more)
▼ In this thesis, the interaction between a femtosecond laser and glasses in the ablation regime is studied. A pulsed femtosecond laser setup allows for surface ablation of glasses under strong focussing conditions. This setup is used to measure the reflectivity of four different glasses as a function of the laser fluence, in order to study the self action of the laser pulse. The craters produced by the laser pulse are examined using atomic force microscopy. These two measurements together are able to provide insights in the energy coupling of the laser pulse into the material. It is found that for increasing fluences, the selfreflectivity and crater depth both rise with increasing slopes. With a similar experimental setup, which uses a
pump and
probe technique, the dynamics of femtosecond laser matter interaction in fused silica are studied under weak focussing conditions. By illuminating the plasma generated by the
pump beam at different times using a delayed
probe beam, its evolution can be observed by its reflectivity. It is seen that in 1 ps, the plasma reaches its maximum reflectivity. The plasma's reflectivity remains constant for several picoseconds, before recombining with the glass. Well after the laser has interacted with the glass, signs of material ablation can be observed. A one-dimensional finite-difference time-domain simulation is performed to replicate the experiment's results. The simulation applies the Drude model and the often used single rate equation developed by Stuart et al. to model ionization. The simulated results do not agree with the experimental results, due to an overestimation of the ionization rate by the single rate equation. Instead, implementation of a multiple rate equation is suggested to model ionization.
Advisors/Committee Members: Oosten, D. van.
Subjects/Keywords: Ablation; Femtosecond laser; Glass; Reflectivity; Drude model; FDTD; Pump probe
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APA (6th Edition):
Clarijs, J. (2016). Femtosecond laser nano-ablation of glass surfaces and their self-scattering effects. (Masters Thesis). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/328402
Chicago Manual of Style (16th Edition):
Clarijs, J. “Femtosecond laser nano-ablation of glass surfaces and their self-scattering effects.” 2016. Masters Thesis, Universiteit Utrecht. Accessed March 06, 2021.
http://dspace.library.uu.nl:8080/handle/1874/328402.
MLA Handbook (7th Edition):
Clarijs, J. “Femtosecond laser nano-ablation of glass surfaces and their self-scattering effects.” 2016. Web. 06 Mar 2021.
Vancouver:
Clarijs J. Femtosecond laser nano-ablation of glass surfaces and their self-scattering effects. [Internet] [Masters thesis]. Universiteit Utrecht; 2016. [cited 2021 Mar 06].
Available from: http://dspace.library.uu.nl:8080/handle/1874/328402.
Council of Science Editors:
Clarijs J. Femtosecond laser nano-ablation of glass surfaces and their self-scattering effects. [Masters Thesis]. Universiteit Utrecht; 2016. Available from: http://dspace.library.uu.nl:8080/handle/1874/328402
12.
Spatzek, Stefan.
Kohärente Kontrolle und
Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs
Quantenpunktensemble.
Degree: 2011, Technische Universität Dortmund
URL: http://hdl.handle.net/2003/28894
► Zur Realisierung eines Quantencomputers muss ein Quantenbit erzeugt, ausgelesen und kontrolliert werden. Ebenso wird eine Quelle der Verschränkung zwischen den Quantenbits benötigt. Der Elektronenspin in…
(more)
▼ Zur Realisierung eines
Quantencomputers muss ein Quantenbit erzeugt, ausgelesen und
kontrolliert werden. Ebenso wird eine Quelle der Verschränkung
zwischen den Quantenbits benötigt. Der Elektronenspin in einen
Quantenpunkt bietet einen Ansatz für die Realisierung eines
Quantenbits. In dieser Arbeit wird gezeigt, wie die Spins effizient
polarisiert werden können. Ebenso wird beschrieben, wie die
Polarisation ausgelesen werden kann. Des Weiteren werden
experimentelle Messungen dargestellt, in denen die Spinpolarisation
innerhalb von Pikosekunden manipuliert wird. Abschließend wird
gezeigt, dass eine Wechselwirkung von Elektronenspins in einem
selbstorganisierten Quantenpunktensemble vorhanden ist.
Advisors/Committee Members: Bayer, Manfred.
Subjects/Keywords: Pump&Probe-Spektroskopie;
Quantenbit; Quanteninformationsverarbeitung; Quantenpunkt;
Ultraschnelle Spinrotation; 530
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APA ·
Chicago ·
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Spatzek, S. (2011). Kohärente Kontrolle und
Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs
Quantenpunktensemble. (Thesis). Technische Universität Dortmund. Retrieved from http://hdl.handle.net/2003/28894
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Spatzek, Stefan. “Kohärente Kontrolle und
Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs
Quantenpunktensemble.” 2011. Thesis, Technische Universität Dortmund. Accessed March 06, 2021.
http://hdl.handle.net/2003/28894.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Spatzek, Stefan. “Kohärente Kontrolle und
Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs
Quantenpunktensemble.” 2011. Web. 06 Mar 2021.
Vancouver:
Spatzek S. Kohärente Kontrolle und
Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs
Quantenpunktensemble. [Internet] [Thesis]. Technische Universität Dortmund; 2011. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2003/28894.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Spatzek S. Kohärente Kontrolle und
Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs
Quantenpunktensemble. [Thesis]. Technische Universität Dortmund; 2011. Available from: http://hdl.handle.net/2003/28894
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
13.
Li, Yuwei.
Time-Resolved Studies and Nanostructure Formation in Sb2Te3 Films Using Femtosecond Lasers.
Degree: PhD, Physics, 2014, University of Michigan
URL: http://hdl.handle.net/2027.42/108790
► Antimony telluride (Sb2Te3) is an important material with a wide range of applications in thermoelectrics, data storage devices and topological insulator research. Our work on…
(more)
▼ Antimony telluride (Sb2Te3) is an important material with a wide range of applications in thermoelectrics, data storage devices and topological insulator research. Our work on femtosecond laser studies of Sb2Te3 films has significance for insights into femtosecond laser interaction with Sb2Te3 above the damage threshold, as well as providing a new pathway for novel fabrication of highly-ordered nanostructured Sb2Te3. These new developments are made possible by careful control of the laser scanning conditions, opening the way to future nanoscale studies and materials applications.
The
pump-
probe scheme for the time-resolved studies employed a novel asynchronous optical sampling (ASOPS) technique, which has distinctive advantages over the traditional mechanical-delay scheme including superior stability of beam alignment during scans, faster data acquisition rates, and the ability to monitor a much wider range of dynamics up to ten nanoseconds. With ASOPS, it is shown that a sequence of connected processes can be studied in Sb2Te3 films, from coherent optical phonons and acoustic echoes at picosecond timescale, through thermal transport at nanosecond timescale. In particular, the coherent phonons were used, for the first time, to monitor the element segregation in Sb2Te3 films under high-fluence
pump laser irradiation conditions. These results are important for the ultrafast spectroscopy research community: they highlight the need for careful interpretation of coherent phonon spectra in tellurides, which are susceptible to fs laser damage.
Femtosecond laser irradiation of Sb2Te3 above ~6 mJ/cm2 was also found to produce highly-ordered nanotracks with a periodicity an order of magnitude below the laser wavelength. A variety of characterization techniques identified these nanotracks as single crystalline Sb2Te3 nanowires separated by polycrystalline phases including a large amount of the insulating Sb2O3. Laser irradiation in different gas environments revealed the sensitivity of the Sb2Te3 surface morphology to the surrounding gas species, especially O2, highlighting the critical role of the ambient environment interactions with Sb2Te3 for nanostructure formation in the thin films. These results provide valuable experimental input for the future analysis of the generation mechanism of these nanostructures. Additionally, the results open up new opportunities for fabrication of in-plane Sb2Te3 nanowires for planar applications.
Advisors/Committee Members: Clarke, Roy (committee member), Pipe, Kevin Patrick (committee member), Kurdak, Cagliyan (committee member), Goldman, Rachel S. (committee member), Uher, Ctirad (committee member).
Subjects/Keywords: Femtosecond Lasers; Antimony Telluride; Nanostructures; Pump-probe; Physics; Science
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APA (6th Edition):
Li, Y. (2014). Time-Resolved Studies and Nanostructure Formation in Sb2Te3 Films Using Femtosecond Lasers. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/108790
Chicago Manual of Style (16th Edition):
Li, Yuwei. “Time-Resolved Studies and Nanostructure Formation in Sb2Te3 Films Using Femtosecond Lasers.” 2014. Doctoral Dissertation, University of Michigan. Accessed March 06, 2021.
http://hdl.handle.net/2027.42/108790.
MLA Handbook (7th Edition):
Li, Yuwei. “Time-Resolved Studies and Nanostructure Formation in Sb2Te3 Films Using Femtosecond Lasers.” 2014. Web. 06 Mar 2021.
Vancouver:
Li Y. Time-Resolved Studies and Nanostructure Formation in Sb2Te3 Films Using Femtosecond Lasers. [Internet] [Doctoral dissertation]. University of Michigan; 2014. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2027.42/108790.
Council of Science Editors:
Li Y. Time-Resolved Studies and Nanostructure Formation in Sb2Te3 Films Using Femtosecond Lasers. [Doctoral Dissertation]. University of Michigan; 2014. Available from: http://hdl.handle.net/2027.42/108790
Texas A&M University
14.
Wan, Qiujie.
Development of Molecular Contrast in Coherence Domain Optical Imaging.
Degree: PhD, Biomedical Engineering, 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10554
► Optical imaging has been developed quickly in the past decades because it has become an important research tool in biology, biochemistry, and biomedical sciences. Coherence…
(more)
▼ Optical imaging has been developed quickly in the past decades because it has become an important research tool in biology, biochemistry, and biomedical sciences. Coherence domain optical imaging is one of the well developed optical imaging modalities, as it provides high resolution and long penetration depth. In this dissertation, we will report our work on development of molecular contrast in coherence domain optical imaging.
In order to image important molecules which are poor fluorophores, we developed a high resolution molecular imaging technique,
pump-
probe optical coherence microscopy (PPOCM), which does not rely on fluorescent tags. PPOCM is the fusion of
Pump-
Probe spectroscopy and optical coherence microscopy (OCM). We have demonstrated the prototype system on a fixed human skin sample containing a nodular melanoma. The results indicate that PPOCM can clearly provide strong contrast between the melanotic and amelanotic regions. This technique can be applied to early diagnosis of melanoma and the mapping of tumor margins during excision. It also can be extended to any biological chromophore with a known absorption spectrum and sufficient concentration. In order to differentiate further multiple chromophores, we developed a spectrally resolved two color
pump-
probe Optical Coherence Microscopy (SRPPOCM). We showed the prototype system on a red hair and a black hair. Our preliminary results show that the SRPPOCM technique could provide a contrast between pheomelanin and eumelanin. This technique could be used potentially as a clinical tool for diagnosing different progression stages of melanoma. This technique could also be applied to differentiate other mixed chromophores.
Second harmonic optical coherence tomography (SHOCT) is non-linear high resolution optical molecular imaging modality which is widely used in non-centrosymmetric material. However, depth ambiguity is associated with SHOCT in tissue sample because forward generated second harmonic signal does not correctly report where the second harmonic signal is generated. We studied the feasibility of collecting the backward generated second harmonic signal from nanocrystals through a Second Harmonic Optical Coherence Tomography in Fourier domain. The preliminary result shows that we can collect backward generated second harmonic signal from nanocrystals which indicates that this technique could suppress the depth ambiguity.
Advisors/Committee Members: Applegate, Brian E. (advisor), Yeh, Alvin T. (committee member), Jo, Javier (committee member), Ji, Jim (committee member).
Subjects/Keywords: Pump-Probe; Optical Coherence Tomography; Second Harmonic Generation
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APA (6th Edition):
Wan, Q. (2012). Development of Molecular Contrast in Coherence Domain Optical Imaging. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10554
Chicago Manual of Style (16th Edition):
Wan, Qiujie. “Development of Molecular Contrast in Coherence Domain Optical Imaging.” 2012. Doctoral Dissertation, Texas A&M University. Accessed March 06, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10554.
MLA Handbook (7th Edition):
Wan, Qiujie. “Development of Molecular Contrast in Coherence Domain Optical Imaging.” 2012. Web. 06 Mar 2021.
Vancouver:
Wan Q. Development of Molecular Contrast in Coherence Domain Optical Imaging. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10554.
Council of Science Editors:
Wan Q. Development of Molecular Contrast in Coherence Domain Optical Imaging. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10554
Penn State University
15.
Larsen, Alec Von.
SPECTROSCOPIC CHARACTERIZATION OF THIN FILM SEMICONDUCTING MATERIALS.
Degree: 2016, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/29531
► The detailed characterization of thin films for use in semiconducting photovoltaic devices is critical in assisting the development of novel materials and processing conditions. Following…
(more)
▼ The detailed characterization of thin films for use in semiconducting photovoltaic devices is critical in assisting the development of novel materials and processing conditions. Following the characterization of thin films in organo-halide perovskites, our results provide useful information to the scientific community about charge carrier recombination centers and their preferential formation on surface and grain boundaries. This information identifies key details that contradict the field’s assumptions about the innocence of grain boundaries in the perovskite films.
To provide a more complete understanding of the photophysics of materials, photothermal deflection spectroscopy was developed in our lab. The use of a solid deflecting medium provided a novel means of investigating optical absorption and non-radiative decay of excited states. Upon completion, this experimental technique provided critical information for the development of a novel spectroscopy, ultra-fast photo thermal deflection spectroscopy.
Advisors/Committee Members: John B Asbury, Thesis Advisor/Co-Advisor, Mark Maroncelli, Thesis Advisor/Co-Advisor, Tom Mallouk, Thesis Advisor/Co-Advisor.
Subjects/Keywords: Perovskite; Spectroscopy; XRD; Ultra-Fast; Pump Probe; Transient Absorption
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Larsen, A. V. (2016). SPECTROSCOPIC CHARACTERIZATION OF THIN FILM SEMICONDUCTING MATERIALS. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/29531
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Larsen, Alec Von. “SPECTROSCOPIC CHARACTERIZATION OF THIN FILM SEMICONDUCTING MATERIALS.” 2016. Thesis, Penn State University. Accessed March 06, 2021.
https://submit-etda.libraries.psu.edu/catalog/29531.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Larsen, Alec Von. “SPECTROSCOPIC CHARACTERIZATION OF THIN FILM SEMICONDUCTING MATERIALS.” 2016. Web. 06 Mar 2021.
Vancouver:
Larsen AV. SPECTROSCOPIC CHARACTERIZATION OF THIN FILM SEMICONDUCTING MATERIALS. [Internet] [Thesis]. Penn State University; 2016. [cited 2021 Mar 06].
Available from: https://submit-etda.libraries.psu.edu/catalog/29531.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Larsen AV. SPECTROSCOPIC CHARACTERIZATION OF THIN FILM SEMICONDUCTING MATERIALS. [Thesis]. Penn State University; 2016. Available from: https://submit-etda.libraries.psu.edu/catalog/29531
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
16.
Wales, Benjamin.
Ultrafast Imaging of Molecular Processes in Small Molecules Using Coulomb Explosion Imaging.
Degree: 2017, University of Waterloo
URL: http://hdl.handle.net/10012/12481
► Molecular structure and dynamics of three molecules (carbonyl sulfide, acetylene, and ethylene) are examined using various implementations of the Coulomb Explosion Imaging technique. Soft x-rays…
(more)
▼ Molecular structure and dynamics of three molecules (carbonyl sulfide, acetylene, and ethylene) are examined using various implementations of the Coulomb Explosion Imaging technique. Soft x-rays from the Canadian Light Source synchrotron are used to ionize OCS doubly, triply, and quadruply. The structural changes and dynamics of the ionization processes and subsequent fragmentation processes are imaged through coincident measurements of ionic fragment momenta. Variations in these processes are explored as a function of photon energy from 90 eV to 173 eV, imaging structural changes as a result of fast (<1 fs) and slow (>1 fs) ionization processes.
Fragmentation processes in OCS 3+ and OCS 4+ are also examined using short, intense, infrared laser pulses of variable pulse length (7 - 500 fs) at the Advanced Laser Light Source. Here, several sequential fragmentation pathways are observed along with pulse-length dependent bond stretching and bending. The extreme case of the latter is shown to open up a new fragmentation pathway for pulse lengths greater than 200 fs.
Proton migration in both the acetylene (HC2H) and ethylene (H2C2H2) cations are imaged using a short pulse (32 and 40 fs) UV-IR pump-probe ionization scheme in order to access the excited cation states which lead to isomerization. For the acetylene molecule, the probe pulse removes two more electrons allowing us to map the momentum vectors of fragments in the channel CH+ + C+ + H+ as a function of time, and thus image the isomerization from HC2H+ into C2H2+. The isomer yield is shown to match theory. Similarly, isomerization of ethylene into ethylidene is imaged, measuring a peak isomerization yield at 100 fs.
Subjects/Keywords: Coulomb Explosion Imaging; Pump-probe; Carbonyl Sulfide; Acetylene; Ethylene; Molecular Dynamics
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APA ·
Chicago ·
MLA ·
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Manager
APA (6th Edition):
Wales, B. (2017). Ultrafast Imaging of Molecular Processes in Small Molecules Using Coulomb Explosion Imaging. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/12481
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wales, Benjamin. “Ultrafast Imaging of Molecular Processes in Small Molecules Using Coulomb Explosion Imaging.” 2017. Thesis, University of Waterloo. Accessed March 06, 2021.
http://hdl.handle.net/10012/12481.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wales, Benjamin. “Ultrafast Imaging of Molecular Processes in Small Molecules Using Coulomb Explosion Imaging.” 2017. Web. 06 Mar 2021.
Vancouver:
Wales B. Ultrafast Imaging of Molecular Processes in Small Molecules Using Coulomb Explosion Imaging. [Internet] [Thesis]. University of Waterloo; 2017. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10012/12481.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wales B. Ultrafast Imaging of Molecular Processes in Small Molecules Using Coulomb Explosion Imaging. [Thesis]. University of Waterloo; 2017. Available from: http://hdl.handle.net/10012/12481
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
NSYSU
17.
Ng, Kuong Ngai.
Carrier Relaxation of InGaN Thin Films.
Degree: Master, Physics, 2018, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0728118-175617
► In this study, the carrier dynamics of InGaN thin films were studied using time resolved pump probe technique (TRPP). This was done by studying the…
(more)
▼ In this study, the carrier dynamics of InGaN thin films were studied using time resolved
pump probe technique (TRPP). This was done by studying the energy released due to excitation and recombination of InGaN thin films in different conditions, such as power density and composition of In. In TRPP spectroscopy, higher
pump power results to a higher decay rate in all the samples. By increasing the composition of In in InGaN, a faster decay was observed. Furthermore, the temperature dependent photoluminescence (PL) spectroscopy was measured in order to determine the band gap of the InGaN thin films. The PL peak energy of InGaN was discovered to increase from 2.38 eV to 2.97 eV as the composition of In was decreased from 0.215 to 0.091.
Advisors/Committee Members: Li-Wei Tu (chair), Der-Jun Jang (committee member), Meng-En Lee (chair).
Subjects/Keywords: InGaN thin film; Pump-Probe; Carrier relaxation; Two colour
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APA (6th Edition):
Ng, K. N. (2018). Carrier Relaxation of InGaN Thin Films. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0728118-175617
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Ng, Kuong Ngai. “Carrier Relaxation of InGaN Thin Films.” 2018. Thesis, NSYSU. Accessed March 06, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0728118-175617.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ng, Kuong Ngai. “Carrier Relaxation of InGaN Thin Films.” 2018. Web. 06 Mar 2021.
Vancouver:
Ng KN. Carrier Relaxation of InGaN Thin Films. [Internet] [Thesis]. NSYSU; 2018. [cited 2021 Mar 06].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0728118-175617.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ng KN. Carrier Relaxation of InGaN Thin Films. [Thesis]. NSYSU; 2018. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0728118-175617
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Boston College
18.
Hicks, Robert Paul.
Probing Electrocatalytic and Photocatalytic Processes with
Structure-Specific Spectroscopies.
Degree: MS, Chemistry, 2019, Boston College
URL: http://dlib.bc.edu/islandora/object/bc-ir:108657
► Studying the adsorption and reaction kinetics of surface-bound chemical species, on different metal catalysts or electrodes, is of paramount importance in the development of inhomogeneous…
(more)
▼ Studying the adsorption and reaction kinetics of
surface-bound chemical species, on different metal catalysts or
electrodes, is of paramount importance in the development of
inhomogeneous catalytic methodology. Our study of the oxidation of
CO on platinum was accomplished by designing a thin layer flow cell
in an external reflection configuration. A charge-injection circuit
was successfully implemented which decreased the time required to
charge the double layer in the electrochemical cell. We were able
to obtain a signal via Stark shift spectrum, of the adsorbed CO,
using the thin layer cell configuration. Additionally,
electrochemical impedance spectroscopy was used as a diagnostic
tool to assess the effect of electrode geometry, on the voltage
response, in the thin layer cell. The coupling of visible
light-driven photoexciation with transition metal catalytic plat-
forms is emerging as a synthetic strategy to achieve unique
reactivity that has previously been inaccessible. One such example
is the iridium/nickel-dipyridyl system discovered recently.
Characterizing the interactions between the iridium and nickel
catalysts, under reaction conditions, is important to develop a
better understanding of the system. In order to apply infrared
spectroscopic measurement techniques, in-situ, we made
modifications to the synthetic scheme by changing the solvent and
by utilizing different iridium catalysts for the synthesis of the
desired methyl 4-(benzoyloxy)benzoate product. Using our trans-
mission infrared setup we effectively demonstrated in-situ product
detection of the aryl- ester coupled product. Additionally, after
constructing a transient infrared
pump-
probe setup, we collected
preliminary results of the triplet state lifetime of the iridium
dye. The surface morphology of copper has been shown to affect the
electrochemical reduction of CO2. Using surface-enhanced Raman
spectroscopies, the reversible formation of nanoscale metal
clusters on a copper electrode was revealed at sufficiently
cathodic potentials where we observed the appearance of a new band
at 2080 cm-1 corresponding to C≡O adsorbed to undercoordinated
copper defect sites. The formation of new undercoordinated sites
additionally resulted in the surface enhancement of the Raman
scattering which amplified the intensity of the other spectral
bands.
Advisors/Committee Members: Matthias M. Waegele (Thesis advisor).
Subjects/Keywords: CO2 reduction; CO oxidation; FTIR; Oxidation; pump probe; Raman
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APA (6th Edition):
Hicks, R. P. (2019). Probing Electrocatalytic and Photocatalytic Processes with
Structure-Specific Spectroscopies. (Masters Thesis). Boston College. Retrieved from http://dlib.bc.edu/islandora/object/bc-ir:108657
Chicago Manual of Style (16th Edition):
Hicks, Robert Paul. “Probing Electrocatalytic and Photocatalytic Processes with
Structure-Specific Spectroscopies.” 2019. Masters Thesis, Boston College. Accessed March 06, 2021.
http://dlib.bc.edu/islandora/object/bc-ir:108657.
MLA Handbook (7th Edition):
Hicks, Robert Paul. “Probing Electrocatalytic and Photocatalytic Processes with
Structure-Specific Spectroscopies.” 2019. Web. 06 Mar 2021.
Vancouver:
Hicks RP. Probing Electrocatalytic and Photocatalytic Processes with
Structure-Specific Spectroscopies. [Internet] [Masters thesis]. Boston College; 2019. [cited 2021 Mar 06].
Available from: http://dlib.bc.edu/islandora/object/bc-ir:108657.
Council of Science Editors:
Hicks RP. Probing Electrocatalytic and Photocatalytic Processes with
Structure-Specific Spectroscopies. [Masters Thesis]. Boston College; 2019. Available from: http://dlib.bc.edu/islandora/object/bc-ir:108657
19.
Spatzek, Stefan.
Kohärente Kontrolle und Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs Quantenpunktensemble.
Degree: 2011, Technische Universität Dortmund
URL: http://dx.doi.org/10.17877/DE290R-1633
► Zur Realisierung eines Quantencomputers muss ein Quantenbit erzeugt, ausgelesen und kontrolliert werden. Ebenso wird eine Quelle der Verschränkung zwischen den Quantenbits benötigt. Der Elektronenspin in…
(more)
▼ Zur Realisierung eines Quantencomputers muss ein Quantenbit erzeugt, ausgelesen und kontrolliert werden. Ebenso wird eine Quelle der Verschränkung zwischen den Quantenbits benötigt. Der Elektronenspin in einen Quantenpunkt bietet einen Ansatz für die Realisierung eines Quantenbits. In dieser Arbeit wird gezeigt, wie die Spins effizient polarisiert werden können. Ebenso wird beschrieben, wie die Polarisation ausgelesen werden kann. Des Weiteren werden experimentelle Messungen dargestellt, in denen die Spinpolarisation innerhalb von Pikosekunden manipuliert wird. Abschließend wird gezeigt, dass eine Wechselwirkung von Elektronenspins in einem selbstorganisierten Quantenpunktensemble vorhanden ist.
Advisors/Committee Members: Bayer, Manfred (advisor), Westphal, Carsten (referee).
Subjects/Keywords: Pump&Probe-Spektroskopie; Quantenbit; Quanteninformationsverarbeitung; Quantenpunkt; Ultraschnelle Spinrotation; 530
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APA (6th Edition):
Spatzek, S. (2011). Kohärente Kontrolle und Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs Quantenpunktensemble. (Doctoral Dissertation). Technische Universität Dortmund. Retrieved from http://dx.doi.org/10.17877/DE290R-1633
Chicago Manual of Style (16th Edition):
Spatzek, Stefan. “Kohärente Kontrolle und Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs Quantenpunktensemble.” 2011. Doctoral Dissertation, Technische Universität Dortmund. Accessed March 06, 2021.
http://dx.doi.org/10.17877/DE290R-1633.
MLA Handbook (7th Edition):
Spatzek, Stefan. “Kohärente Kontrolle und Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs Quantenpunktensemble.” 2011. Web. 06 Mar 2021.
Vancouver:
Spatzek S. Kohärente Kontrolle und Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs Quantenpunktensemble. [Internet] [Doctoral dissertation]. Technische Universität Dortmund; 2011. [cited 2021 Mar 06].
Available from: http://dx.doi.org/10.17877/DE290R-1633.
Council of Science Editors:
Spatzek S. Kohärente Kontrolle und Wechselwirkung von Elektronenspins in einem (In,Ga)As/GaAs Quantenpunktensemble. [Doctoral Dissertation]. Technische Universität Dortmund; 2011. Available from: http://dx.doi.org/10.17877/DE290R-1633
20.
Pohl, Martin.
Ultrafast optical phenomena in magneto-plasmonic crystals and magnetically ordered materials.
Degree: 2014, Technische Universität Dortmund
URL: http://dx.doi.org/10.17877/DE290R-13719
► The understanding and control of fundamental light-matter interactions is able to provide solutions for current challenges concerning light-emitting diodes, solar-cells, microchip design, data storage and…
(more)
▼ The understanding and control of fundamental light-matter interactions is able to provide solutions for current challenges concerning light-emitting diodes, solar-cells, microchip design, data storage and many more. Driven by the need of compact, fast and energy efficient device technologies, ultrafast optical phenomena are studied in different material systems by means of femtosecond time-resolved
pump-
probe techniques. The presented experiments focus on magneto-optic phenomena as a tool for external optical control. By means of femtosecond laser pulses, these are observed on timescales comparable to the exchange interaction or typical electron scattering times, which grants deep insight into the electronic processes involved. The aim is to gain fundamental knowledge for the optical control of the material’s magneto-optical properties for all-optical applications. In magneto-plasmonic crystals, surface plasmon polaritons provide a versatile and
efficient tool due to the concentration of optical energy to subwavelength dimensions. Mott insulators, on the other hand are
subject to strong exchange interactions. It is shown that the optical properties in these systems can be manipulated on timescales between 10 and 500 femtoseconds. In magnetic iron garnets, non-thermal ways for the optical control of the magnetization are investigated. The obtained knowledge is then combined with plasmonic enhancement with a view to ultrafast magnetic switching in modern data storage technologies.
Advisors/Committee Members: Akimov, Ilya (advisor), Hövel, Heinz (referee).
Subjects/Keywords: Femtosekunden-Optik; Pump-Probe Spektroskopie; Magneto-Optik; Plasmonik; Halbleiter; 530
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MLA ·
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CSE |
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APA (6th Edition):
Pohl, M. (2014). Ultrafast optical phenomena in magneto-plasmonic crystals and magnetically ordered materials. (Doctoral Dissertation). Technische Universität Dortmund. Retrieved from http://dx.doi.org/10.17877/DE290R-13719
Chicago Manual of Style (16th Edition):
Pohl, Martin. “Ultrafast optical phenomena in magneto-plasmonic crystals and magnetically ordered materials.” 2014. Doctoral Dissertation, Technische Universität Dortmund. Accessed March 06, 2021.
http://dx.doi.org/10.17877/DE290R-13719.
MLA Handbook (7th Edition):
Pohl, Martin. “Ultrafast optical phenomena in magneto-plasmonic crystals and magnetically ordered materials.” 2014. Web. 06 Mar 2021.
Vancouver:
Pohl M. Ultrafast optical phenomena in magneto-plasmonic crystals and magnetically ordered materials. [Internet] [Doctoral dissertation]. Technische Universität Dortmund; 2014. [cited 2021 Mar 06].
Available from: http://dx.doi.org/10.17877/DE290R-13719.
Council of Science Editors:
Pohl M. Ultrafast optical phenomena in magneto-plasmonic crystals and magnetically ordered materials. [Doctoral Dissertation]. Technische Universität Dortmund; 2014. Available from: http://dx.doi.org/10.17877/DE290R-13719
Vrije Universiteit Amsterdam
21.
Stahl, A.D.
Structure-function relationship in photosynthetic and photo-active proteins: A mid-Infrared investigation with femtosecond time resolution
.
Degree: 2011, Vrije Universiteit Amsterdam
URL: http://hdl.handle.net/1871/23951
Subjects/Keywords: femtosecond infrared pump-probe
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CSE |
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APA (6th Edition):
Stahl, A. D. (2011). Structure-function relationship in photosynthetic and photo-active proteins: A mid-Infrared investigation with femtosecond time resolution
. (Doctoral Dissertation). Vrije Universiteit Amsterdam. Retrieved from http://hdl.handle.net/1871/23951
Chicago Manual of Style (16th Edition):
Stahl, A D. “Structure-function relationship in photosynthetic and photo-active proteins: A mid-Infrared investigation with femtosecond time resolution
.” 2011. Doctoral Dissertation, Vrije Universiteit Amsterdam. Accessed March 06, 2021.
http://hdl.handle.net/1871/23951.
MLA Handbook (7th Edition):
Stahl, A D. “Structure-function relationship in photosynthetic and photo-active proteins: A mid-Infrared investigation with femtosecond time resolution
.” 2011. Web. 06 Mar 2021.
Vancouver:
Stahl AD. Structure-function relationship in photosynthetic and photo-active proteins: A mid-Infrared investigation with femtosecond time resolution
. [Internet] [Doctoral dissertation]. Vrije Universiteit Amsterdam; 2011. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1871/23951.
Council of Science Editors:
Stahl AD. Structure-function relationship in photosynthetic and photo-active proteins: A mid-Infrared investigation with femtosecond time resolution
. [Doctoral Dissertation]. Vrije Universiteit Amsterdam; 2011. Available from: http://hdl.handle.net/1871/23951
University of Colorado
22.
Buckley, Danielle M.
Carrier Dynamics of Colloidal Solutions and Arrays of Lead Chalcogenide Quantum Dots.
Degree: PhD, Chemistry & Biochemistry, 2014, University of Colorado
URL: https://scholar.colorado.edu/chem_gradetds/121
► While quantum dots (QDs) potentially offer routes to increase the efficiency of solar energy harvesting, fundamental photophysical processes, such as carrier cooling, are still…
(more)
▼ While quantum dots (QDs) potentially offer routes to increase the efficiency of solar energy harvesting, fundamental photophysical processes, such as carrier cooling, are still not fully understood. Ultrafast degenerate
pump-
probe spectroscopy is used to investigate carrier dynamics in both isolated colloidal quantum dots, uncoupled quantum dot arrays, and most importantly, coupled quantum dot arrays that may be suitable for device applications. Pumping and probing at the same wavelength overcomes frequency-dependent absorption cross-section issues that may complicate results. Additionally, utilizing novel sample refreshing techniques minimizes photodegradation and photocharging.
The time-dependent behavior of PbS nanocrystal arrays and colloidal solutions is measured at the band gap with sub-100fs time resolution and at higher photon energies with sub-40fs resolution. Different ligand treatments are employed to exchange bulky long-chain organics for shorter chains with different functional groups. Ligand exchange is performed on films as well as a colloidal solution.
Investigations of 2nm diameter PbS quantum dots at the band gap and at 1.4 times the band gap show the biexciton lifetime in an uncoupled array is the same as in colloidal solution. This is in contrast to previous reports of different decay times for various sizes of PbSe QD solutions and uncoupled arrays. Degenerate studies of these same 2nm diameter PbS QDs as coupled arrays at the band gap indicate substantial excited state absorption that increases with increasing
pump fluence.
Advisors/Committee Members: David Jonas, Gordana Dukovic, Veronica Vaida, Robert Parson, Henry Kapteyn.
Subjects/Keywords: degenerate pump probe; lead sulfide; quantum dots; ultrafast spectroscopy; Physical Chemistry
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APA (6th Edition):
Buckley, D. M. (2014). Carrier Dynamics of Colloidal Solutions and Arrays of Lead Chalcogenide Quantum Dots. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/chem_gradetds/121
Chicago Manual of Style (16th Edition):
Buckley, Danielle M. “Carrier Dynamics of Colloidal Solutions and Arrays of Lead Chalcogenide Quantum Dots.” 2014. Doctoral Dissertation, University of Colorado. Accessed March 06, 2021.
https://scholar.colorado.edu/chem_gradetds/121.
MLA Handbook (7th Edition):
Buckley, Danielle M. “Carrier Dynamics of Colloidal Solutions and Arrays of Lead Chalcogenide Quantum Dots.” 2014. Web. 06 Mar 2021.
Vancouver:
Buckley DM. Carrier Dynamics of Colloidal Solutions and Arrays of Lead Chalcogenide Quantum Dots. [Internet] [Doctoral dissertation]. University of Colorado; 2014. [cited 2021 Mar 06].
Available from: https://scholar.colorado.edu/chem_gradetds/121.
Council of Science Editors:
Buckley DM. Carrier Dynamics of Colloidal Solutions and Arrays of Lead Chalcogenide Quantum Dots. [Doctoral Dissertation]. University of Colorado; 2014. Available from: https://scholar.colorado.edu/chem_gradetds/121
University of Illinois – Urbana-Champaign
23.
Yang, Kexin.
Magnetic and thermal properties of metallic antiferromagnetic materials.
Degree: PhD, Physics, 2020, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/108482
► Metallic antiferromagnetic materials are of great potential in spintronics due to their insensitivity to external fields and faster dynamics compared to typical ferromagnetic materials. Although…
(more)
▼ Metallic antiferromagnetic materials are of great potential in spintronics due to their insensitivity to external fields and faster dynamics compared to typical ferromagnetic materials. Although they have these advantages, studies of their order parameter is difficult to perform because of the lack of net magnetization.
The linear magneto-optic Kerr effect (MOKE) is often used to
probe magnetism of ferromagnetic materials, but MOKE cannot be applied to collinear antiferromagnets due to the cancellation of sublattice magnetization. Magneto-optic constants that are quadratic in magnetization, however, provide an approach for studying antiferromagnets on picosecond timescales.
I combined transient measurements of linear birefringence and optical reflectivity to study the optical response of Fe2As to small ultrafast temperature excursions. We performed temperature-dependent pumpprobe measurements on crystallographically isotropic (001) and anisotropic (010) faces of Fe2As bulk crystals and found that the largest optical signals arise from changes in the index of refraction along the z-axis, perpendicular to the Neel vector. Both real and imaginary parts of the transient optical birefringence signal approximately follow the temperature dependence of the magnetic heat capacity, as expected if the changes in dielectric function are dominated by contributions of exchange interactions to the dielectric function.
In spintronic devices, it is essential to determine the dynamics of magnetic precession, the frequency of spin waves, the thermal stability of magnetic domains, and the efficiency. Thus magnetocrystalline anisotropy is a fundamental property of antiferromagnetic materials. Torque magnetometry measurements of Fe2As were performed. We reported that the four-fold magnetocrystalline anisotropy K22 in the (001)-plane of Fe2As is K22 = −150 kJ/m
3 at T = 4 K, much smaller than the perpendicular magnetic anisotropy of ferromagnetic materials structure widely used in spintronics device. K22 is strongly temperature dependent and close to zero at T > 150 K. The anisotropy K1 in the (010) plane is too large to be measured by torque magnetometry and we determine K1 = −830 kJ/m
3 using first-principles density functional theory. Our simulations show that the contribution to the anisotropy from classical magnetic dipole-dipole interactions is comparable to the contribution from spin-orbit coupling. The calculated four-fold anisotropy in the (001) plane K22 ranges from −290 to 280 kJ/m
3, the same order of magnitude as the measured value. We used K1 from theory to predict the frequency and polarization of the lowest frequency antiferromagnetic resonance mode and find that the mode is linearly polarized in the (001)-plane with frequency 670 GHz.
As we observed The field-dependent domain distribution and quadratic magnetization can potentially be measured with optical technique. We set up a static system for imaging in-plane magnetic domains. To test this system, I measured the quadratic MOKE coefficient of ferromagnetic cobalt…
Advisors/Committee Members: Cahill, David G. (advisor), Mason, Nadya (Committee Chair), Schleife, Andre (committee member), Lorenz, Virginia O. (committee member).
Subjects/Keywords: Magnetism; magneto-optical effects; magnetometry; pump-probe techniques
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Manager
APA (6th Edition):
Yang, K. (2020). Magnetic and thermal properties of metallic antiferromagnetic materials. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/108482
Chicago Manual of Style (16th Edition):
Yang, Kexin. “Magnetic and thermal properties of metallic antiferromagnetic materials.” 2020. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed March 06, 2021.
http://hdl.handle.net/2142/108482.
MLA Handbook (7th Edition):
Yang, Kexin. “Magnetic and thermal properties of metallic antiferromagnetic materials.” 2020. Web. 06 Mar 2021.
Vancouver:
Yang K. Magnetic and thermal properties of metallic antiferromagnetic materials. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2020. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2142/108482.
Council of Science Editors:
Yang K. Magnetic and thermal properties of metallic antiferromagnetic materials. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2020. Available from: http://hdl.handle.net/2142/108482
University of Southern California
24.
Rivera, Christopher Andrew.
Ultrafast spectroscopic interrogation and simulation of
excited states and reactive surfaces.
Degree: PhD, Chemistry (Chemical Physics), 2011, University of Southern California
URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/433284/rec/7657
► Making a movie of a chemical reaction requires intricate knowledge of both the chemical actors and the environment. Furthermore, the subtleties of the reactive surfaces…
(more)
▼ Making a movie of a chemical reaction requires
intricate knowledge of both the chemical actors and the
environment. Furthermore, the subtleties of the reactive surfaces
and the effect of external forces such as solvent electrostatics
and molecular collisions on these surfaces often play a major role
in the reaction outcome. Many of these external effects begin
influencing the reaction within tens of femtoseconds, requiring
sophisticated experimental techniques in order to observe dynamics
on these timescales.; Ultrafast
pump-
probe spectroscopy is employed
to study the benchmark ICN Ã photodissociation reaction. This
prototypical triatomic system is known to produce a highly
non-equilibrium distribution of rotationally excited cyano
radicals. The generation of these rotors comes from a non-adiabatic
transition which applies extra torque to an already rapidly bending
I-CN bond and leads to two product states corresponding to the
I*(²P1/2) + cold CN and I(²P3/2) + hot CN channel. Simulations show
that this rotationally excited CN pushes solvent molecules out of
the way to create a cavity where free rotation takes place for
several picoseconds. Our hypothesis is that this spinning CN
resembles a gas phase molecule, and thus should have a gas phase
spectral signature.; Although the relaxation of the hot CN takes
place on relatively long time scales for ultrafast spectroscopists,
the initial curve crossing event takes place much earlier
(
Advisors/Committee Members: Bradforth, Stephen E. (Committee Chair), Reisler, Hannah (Committee Member), Haworth, Ian S. (Committee Member).
Subjects/Keywords: molecular dynamics; photodissociation; pump-probe; spectroscopy; time-resolved; ultrafast
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Manager
APA (6th Edition):
Rivera, C. A. (2011). Ultrafast spectroscopic interrogation and simulation of
excited states and reactive surfaces. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/433284/rec/7657
Chicago Manual of Style (16th Edition):
Rivera, Christopher Andrew. “Ultrafast spectroscopic interrogation and simulation of
excited states and reactive surfaces.” 2011. Doctoral Dissertation, University of Southern California. Accessed March 06, 2021.
http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/433284/rec/7657.
MLA Handbook (7th Edition):
Rivera, Christopher Andrew. “Ultrafast spectroscopic interrogation and simulation of
excited states and reactive surfaces.” 2011. Web. 06 Mar 2021.
Vancouver:
Rivera CA. Ultrafast spectroscopic interrogation and simulation of
excited states and reactive surfaces. [Internet] [Doctoral dissertation]. University of Southern California; 2011. [cited 2021 Mar 06].
Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/433284/rec/7657.
Council of Science Editors:
Rivera CA. Ultrafast spectroscopic interrogation and simulation of
excited states and reactive surfaces. [Doctoral Dissertation]. University of Southern California; 2011. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/433284/rec/7657
Duke University
25.
Simpson, Mary Jane.
Melanin Chemistry Revealed by Excited State Dynamics and the Resulting Biological Implications
.
Degree: 2014, Duke University
URL: http://hdl.handle.net/10161/8785
► Dermatopathologists need more reliable tools for analyzing biopsies of lesions that are potentially melanomas and determining the best treatment plan for the patient. Previously…
(more)
▼ Dermatopathologists need more reliable tools for analyzing biopsies of lesions that are potentially melanomas and determining the best treatment plan for the patient. Previously inaccessible, the chemical and physical properties of melanin provide insight into melanoma biochemistry. Two-color, near-infrared
pump-
probe microscopy of unstained, human pathology slides reveals differences in the type of melanins and the distribution of melanins between melanomas and benign nevi. Because the
pump-
probe response of melanin is resilient to aging, even for hundreds of millions of years, this tool could prove useful in retrospective studies to correlate melanin characteristics with patient outcome, thus eliminating the pathologist's uncertainty from the development of this classification method.
Pump-
probe spectroscopy of a variety of melanin preparations including melanins with varying amounts of metal ions and toxins, those that have been photo-damaged or chemically oxidized, and melanins with a homogeneous size distribution shows that the
pump-
probe response is sensitive to these chemical and physical differences, not just melanin type as previously hypothesized. When sampling the response at several
pump wavelengths, the specificity of this technique is derived from the absorption spectra of the underlying chromophores. Therefore, hyperspectral
pump-
probe microscopy of melanin could serve as an indicator of the chemical environment in a variety of biological contexts. For example, the melanin chemistry of macrophages suggests that these cells oxidize, homogenize, and compact melanin granules; whereas melanocytes produce heterogeneous melanins.
Advisors/Committee Members: Warren, Warren S (advisor).
Subjects/Keywords: Physical chemistry;
melanin;
melanoma;
microscopy;
nonlinear optics;
pump-probe;
spectroscopy
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APA (6th Edition):
Simpson, M. J. (2014). Melanin Chemistry Revealed by Excited State Dynamics and the Resulting Biological Implications
. (Thesis). Duke University. Retrieved from http://hdl.handle.net/10161/8785
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Simpson, Mary Jane. “Melanin Chemistry Revealed by Excited State Dynamics and the Resulting Biological Implications
.” 2014. Thesis, Duke University. Accessed March 06, 2021.
http://hdl.handle.net/10161/8785.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Simpson, Mary Jane. “Melanin Chemistry Revealed by Excited State Dynamics and the Resulting Biological Implications
.” 2014. Web. 06 Mar 2021.
Vancouver:
Simpson MJ. Melanin Chemistry Revealed by Excited State Dynamics and the Resulting Biological Implications
. [Internet] [Thesis]. Duke University; 2014. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10161/8785.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Simpson MJ. Melanin Chemistry Revealed by Excited State Dynamics and the Resulting Biological Implications
. [Thesis]. Duke University; 2014. Available from: http://hdl.handle.net/10161/8785
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Duke University
26.
Matthews, Thomas.
Pump-Probe Molecular Imaging
.
Degree: 2011, Duke University
URL: http://hdl.handle.net/10161/5685
► In this dissertation, we develop pump probe spectroscopy as a method to differentiate different chemical varieties of melanin, a common biopigment, and exploit these…
(more)
▼ In this dissertation, we develop
pump probe spectroscopy as a method to differentiate different chemical varieties of melanin, a common biopigment, and exploit these differences to improve the accuracy of melanoma diagnosis. This method gives insight into the chemical makeup and secondary structure of melanins.
Pump probe spectroscopy is implemented in a scanning laser microscope as a form of multiphoton imaging, where it is used to image biopsies of human pigmented cutaneous lesions. Melanoma diagnosis is clinically challenging: the accuracy of visual inspection by dermatologists is highly variable and heavily weighted toward false positives. Even the current gold standard of biopsy results in varying diagnoses among pathologists. Using
pump probe imaging, significant chemical and morphological changes were found between melanoma and melanocytic nevi, including increased eumelanin content, chemical heterogeneity and general pigmentation. Signal processing methods revealed further differences between melanoma and melanocytic nevi on the cellular scale.
Pump probe imaging directly in H&E stained biopsy samples allows integration of this technique with existing histopathology protocols. High resolution imaging found chemical heterogeneity of melanin within pigmented cells. We show that oxyhemoglobin and deoxyhemoglobin may also be differentiated by
pump probe imaging. Epi mode imaging of eumelanin, pheomelanin and microvasculature is demonstrated in vivo in human xenograft mouse models of melanoma.
Advisors/Committee Members: Warren, Warren S (advisor).
Subjects/Keywords: Physical Chemistry;
Biomedical Engineering;
Optics;
melanoma;
multiphoton imaging;
pump-probe
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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Manager
APA (6th Edition):
Matthews, T. (2011). Pump-Probe Molecular Imaging
. (Thesis). Duke University. Retrieved from http://hdl.handle.net/10161/5685
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Matthews, Thomas. “Pump-Probe Molecular Imaging
.” 2011. Thesis, Duke University. Accessed March 06, 2021.
http://hdl.handle.net/10161/5685.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Matthews, Thomas. “Pump-Probe Molecular Imaging
.” 2011. Web. 06 Mar 2021.
Vancouver:
Matthews T. Pump-Probe Molecular Imaging
. [Internet] [Thesis]. Duke University; 2011. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10161/5685.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Matthews T. Pump-Probe Molecular Imaging
. [Thesis]. Duke University; 2011. Available from: http://hdl.handle.net/10161/5685
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Maryland
27.
Jadidi, Mohammad Mehdi.
Plasmonic and Ultrafast Optical Response of 2D and 3D Dirac Materials.
Degree: Electrical Engineering, 2016, University of Maryland
URL: http://hdl.handle.net/1903/19078
► The fast-evolving field of condensed matter physics is witnessing a rapid development of a new class of materials, called Dirac materials. The low-energy electronic excitation…
(more)
▼ The fast-evolving field of condensed matter physics is witnessing a rapid development of a new class of materials, called Dirac materials. The low-energy electronic excitation in these materials behaves like massless Dirac particles. These materials exhibit unique optoelectronic properties, and understanding of Dirac quasi-particle dynamics in two and three dimensions is imperative to realizing the potential applications.
In this dissertation, we study two prominent Dirac materials that have unique optoelectronic properties: graphene (two-dimensional) and tantalum arsenide (three-dimensional). While the former can be regarded as the father of materials with a symmetry-protected Dirac spectrum, the latter is a more recent example of topology-protected Dirac materials, also known as 3D Weyl semimetals. We employ spectroscopy and ultrafast optical techniques to study plasmons, and the interaction/relaxation dynamics of photo-excited carriers in these materials.
More specifically, we study a new class of plasmon resonances in hybrid metal-graphene structures, which is an important step towards practical graphene plasmonic optoelectronic devices. In addition, we investigate the giant nonlinear THz response of graphene plasmons using
pump-
probe techniques and discuss the physical origin of the plasmon-enhanced nonlinearity. Furthermore, we introduce a novel continuous-wave photomixing spectroscopy technique to investigate the frequency dependence and nonlinearity of hot-electron cooling in graphene. Finally, we explore the relaxation dynamics of photo-excited Weyl fermions in tantalum arsenide via ultrafast optical
pump-
probe techniques, which shed light on the electron-phonon relaxation processes in this material.
Advisors/Committee Members: Murphy, Thomas E. (advisor).
Subjects/Keywords: Physics; Dirac Materials; Graphene; Plasmonics; pump-probe; Ultrafast Optics; Weyl Semimetals
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APA (6th Edition):
Jadidi, M. M. (2016). Plasmonic and Ultrafast Optical Response of 2D and 3D Dirac Materials. (Thesis). University of Maryland. Retrieved from http://hdl.handle.net/1903/19078
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Jadidi, Mohammad Mehdi. “Plasmonic and Ultrafast Optical Response of 2D and 3D Dirac Materials.” 2016. Thesis, University of Maryland. Accessed March 06, 2021.
http://hdl.handle.net/1903/19078.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Jadidi, Mohammad Mehdi. “Plasmonic and Ultrafast Optical Response of 2D and 3D Dirac Materials.” 2016. Web. 06 Mar 2021.
Vancouver:
Jadidi MM. Plasmonic and Ultrafast Optical Response of 2D and 3D Dirac Materials. [Internet] [Thesis]. University of Maryland; 2016. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1903/19078.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Jadidi MM. Plasmonic and Ultrafast Optical Response of 2D and 3D Dirac Materials. [Thesis]. University of Maryland; 2016. Available from: http://hdl.handle.net/1903/19078
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Minnesota
28.
Wu, Xuewang.
Thermal Transport In Nanostructured Materials By Ultrafast Pump-Probe Techniques.
Degree: PhD, Mechanical Engineering, 2019, University of Minnesota
URL: http://hdl.handle.net/11299/215113
► Thermal transport in nanostructured materials is crucial to nanotechnology-initiated applications such as electronics, solid-state energy conversion, and biomedical applications. At reduced size, the thermal properties…
(more)
▼ Thermal transport in nanostructured materials is crucial to nanotechnology-initiated applications such as electronics, solid-state energy conversion, and biomedical applications. At reduced size, the thermal properties of nanostructured materials can differ greatly from their bulk counterparts due to events such as the scattering of heat carriers. New experimental techniques, which can detect the nanoscale thermal properties, are needed to promote further study in this field. Pump-probe optical techniques, which utilize ultrafast laser pulses with a very short duration time and high-power objective lenses to achieve high temporal and spatial resolutions, make it feasible. Our studies were motivated to advance the understandings of thermal transport in nanostructured materials as functions of various structural parameters, utilizing pump-probe optical techniques and numerical/theoretical methods. In this dissertation, I have presented three research projects of thermal transport in different novel nanostructured materials including ultrathin films, nanoparticles, and nanocomposite. First, we extract the glass-like thermal conductivities of single-crystalline La0.5Sr0.5CoO2.9 (LSCO) epitaxial films with “built-in ordered oxygen vacancies”, through Time-domain thermoreflectance (TDTR) and linear extrapolation. Molecular dynamics simulation (MD) and Boltzmann Transport Equation (BTE) are applied to reveal the suppression mechanisms on thermal conductivity of LSCO due to structural parameters including the oxygen vacancies and orderings, film thickness, and substitution. Second, we study thermal transport across cetyltrimethylammonium bromide (CTAB) and polyethylene glycol (PEG) surfactants on gold nanorods (GNRs) in water solution, utilizing transient absorption (TA) technique. We notice a better thermal performance in PEG compared to that in CTAB on GNRs. Through a multiscale thermal modeling with the incorporation of MD simulation, we reveal such better thermal performance in PEG is due to water penetration and strong covalent bonding between GNR and PEG, which are not present in CTAB. Finally, we report thermal conductivities of direct-contact ZnO nanocrystal (NC) networks with infill materials of ZnO and/or Al2O3 by TDTR, as functions of contact radius between adjacent NCs, doping concentration, and the infill composition. A modified effective medium approximation model is applied to validate the experiment results and reveal the influences of various parameters on the thermal conductivity of this nanocomposite sample system.
Subjects/Keywords: Gold nanorod; Nanocrystal; Nanostructured material; Perovskite; Pump-probe techniques; Thermal transport
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Wu, X. (2019). Thermal Transport In Nanostructured Materials By Ultrafast Pump-Probe Techniques. (Doctoral Dissertation). University of Minnesota. Retrieved from http://hdl.handle.net/11299/215113
Chicago Manual of Style (16th Edition):
Wu, Xuewang. “Thermal Transport In Nanostructured Materials By Ultrafast Pump-Probe Techniques.” 2019. Doctoral Dissertation, University of Minnesota. Accessed March 06, 2021.
http://hdl.handle.net/11299/215113.
MLA Handbook (7th Edition):
Wu, Xuewang. “Thermal Transport In Nanostructured Materials By Ultrafast Pump-Probe Techniques.” 2019. Web. 06 Mar 2021.
Vancouver:
Wu X. Thermal Transport In Nanostructured Materials By Ultrafast Pump-Probe Techniques. [Internet] [Doctoral dissertation]. University of Minnesota; 2019. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/11299/215113.
Council of Science Editors:
Wu X. Thermal Transport In Nanostructured Materials By Ultrafast Pump-Probe Techniques. [Doctoral Dissertation]. University of Minnesota; 2019. Available from: http://hdl.handle.net/11299/215113
University of Cambridge
29.
Hinrichsen, Ture Fabian.
Spectroscopic studies of charge dynamics in non-fullerene organic solar cells.
Degree: PhD, 2019, University of Cambridge
URL: https://doi.org/10.17863/CAM.51384
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805910
► Organic solar cells (OSCs) are a promising technology for emission-free electricity supply. However, low power conversion efficiencies and poor device stabilities have so far prevented…
(more)
▼ Organic solar cells (OSCs) are a promising technology for emission-free electricity supply. However, low power conversion efficiencies and poor device stabilities have so far prevented widespread commercial applications. Remarkable progress has been made recently by the development of non-fullerene electron acceptor materials. They benefit from good tunablity of energy levels as well as greater thermal and photochemical stability, and remarkable power conversion efficiencies of up to 16.5 % have been achieved. Furthermore, they have shown efficient charge separation with negligible energy loss, overcoming one of the crucial limitations of fullerene based OSC. Here, we present a study on the charge generation, separation, and recombination dynamics of non-fullerene solar cells. We investigate the model system P3TEA:SF-PDI₂ via pump-probe spectroscopy and time-resolved photoluminescence spectroscopy. We find ultrafast charge generation as well as regeneration of singlets via encounters of free electrons and holes. Additionally, we observe slow (~ 100 ps) and thermally activated charge separation from vibrationally relaxed charge transfer exciton (CTE) states. To directly track the CTE population, we employ pump-push-probe spectroscopy. Our results suggest that singlet excitons, CTE states, and free charges form an equilibrium, with reversible interconversion between them. These systems are therefore not limited by the need to provide excess energy to overcome the Coulomb binding energy. Thus, future efforts to improve efficiencies should focus on removing energy offsets and irreversible processes, such as non-radiative recombination. Furthermore, we study PBDB-T:ITIC, a material that was used in the first non-fullerene cell that exceeded 10 % efficiency. We find that the charge generation occurs on a ~ 10 ps timescale, several orders of magnitude slower than in efficient fullerene-based systems. Additionally, we identify two different pathways for non-radiative decay: triplet generation in the polymer and trap-assisted charge recombination.
Subjects/Keywords: non-fullerene acceptors; organic solar cells; organic photovoltaics; pump-probe spectroscopy; pump-push-probe spectroscopy; transient absorption spectroscopy; charge transfer; charge sepearation; charge generation
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APA (6th Edition):
Hinrichsen, T. F. (2019). Spectroscopic studies of charge dynamics in non-fullerene organic solar cells. (Doctoral Dissertation). University of Cambridge. Retrieved from https://doi.org/10.17863/CAM.51384 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805910
Chicago Manual of Style (16th Edition):
Hinrichsen, Ture Fabian. “Spectroscopic studies of charge dynamics in non-fullerene organic solar cells.” 2019. Doctoral Dissertation, University of Cambridge. Accessed March 06, 2021.
https://doi.org/10.17863/CAM.51384 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805910.
MLA Handbook (7th Edition):
Hinrichsen, Ture Fabian. “Spectroscopic studies of charge dynamics in non-fullerene organic solar cells.” 2019. Web. 06 Mar 2021.
Vancouver:
Hinrichsen TF. Spectroscopic studies of charge dynamics in non-fullerene organic solar cells. [Internet] [Doctoral dissertation]. University of Cambridge; 2019. [cited 2021 Mar 06].
Available from: https://doi.org/10.17863/CAM.51384 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805910.
Council of Science Editors:
Hinrichsen TF. Spectroscopic studies of charge dynamics in non-fullerene organic solar cells. [Doctoral Dissertation]. University of Cambridge; 2019. Available from: https://doi.org/10.17863/CAM.51384 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805910
NSYSU
30.
Chen, Hsuan-Yin.
Saturable Absorption and Ultrafast Carrier Dynamics Study of Topological Insulators.
Degree: Master, Electro-Optical Engineering, 2016, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0527116-155259
► In this thesis, carrier dynamics and phonon propagation of topological insulators are investigated using novel pump-probe technique. First, the evolution of carrier dynamics of Bi2Te3…
(more)
▼ In this thesis, carrier dynamics and phonon propagation of topological insulators are investigated using novel
pump-
probe technique. First, the evolution of carrier dynamics of Bi2Te3 thin films from unsaturated to saturated condition was characterized by extremely low excitation condition. The competition between surface state and bulk state was proposed to interpret the clear trend of which the bulk state will dominate the behavior as decreasing film thickness.
Regarding to the phonon propagation of topological insulator Bi2Se3 thin films, a new type of reflective
pump probe which the
pump and
probe beam excite the film on the opposite side was buildup. The result of clear coherent phonon behavior further confirm the conclusion from typical reflective
pump probe measurement. Additionally, the result indicated the nature of phonon propagation. Furthermore, thickness dependent of phonon life time and relaxation time are also discussed.
Advisors/Committee Members: Chao-Kuei Lee (committee member), Yuan-Yao Lin (chair), Ann-Kuo Chu (chair), Cheng-Maw Cheng (chair), Yi-Jen Chiu (chair).
Subjects/Keywords: Topological insulators; Bi2Se3; Coherent phonon; Bi2Te3; Pump-probe technique; Saturable absorption; Surface state; Bulk state
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APA ·
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APA (6th Edition):
Chen, H. (2016). Saturable Absorption and Ultrafast Carrier Dynamics Study of Topological Insulators. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0527116-155259
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chen, Hsuan-Yin. “Saturable Absorption and Ultrafast Carrier Dynamics Study of Topological Insulators.” 2016. Thesis, NSYSU. Accessed March 06, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0527116-155259.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chen, Hsuan-Yin. “Saturable Absorption and Ultrafast Carrier Dynamics Study of Topological Insulators.” 2016. Web. 06 Mar 2021.
Vancouver:
Chen H. Saturable Absorption and Ultrafast Carrier Dynamics Study of Topological Insulators. [Internet] [Thesis]. NSYSU; 2016. [cited 2021 Mar 06].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0527116-155259.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chen H. Saturable Absorption and Ultrafast Carrier Dynamics Study of Topological Insulators. [Thesis]. NSYSU; 2016. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0527116-155259
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
◁ [1] [2] [3] [4] [5] [6] ▶
. 
Open Access Theses and Dissertations
