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University of Oklahoma
1.
Bokalawela, Roshan S. P.
NANO INTEGRATED LITHIUM POLYMER ELECTROLYTES BASED ON ANODIC ALUMINUM OXIDE (AAO) TEMPLATES.
Degree: PhD, 2012, University of Oklahoma
URL: http://hdl.handle.net/11244/319028
The Appendices at the end of this thesis include details of the developed procedures and apparatus, as well as additional experimental results not shown in the thesis.
Advisors/Committee Members: Johnson, Matthew B (advisor).
Subjects/Keywords: Polyelectrolytes; Aluminum oxide; Metals – Anodic oxidization; Lithium; Electrolytes – Conductivity
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APA (6th Edition):
Bokalawela, R. S. P. (2012). NANO INTEGRATED LITHIUM POLYMER ELECTROLYTES BASED ON ANODIC ALUMINUM OXIDE (AAO) TEMPLATES. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/319028
Chicago Manual of Style (16th Edition):
Bokalawela, Roshan S P. “NANO INTEGRATED LITHIUM POLYMER ELECTROLYTES BASED ON ANODIC ALUMINUM OXIDE (AAO) TEMPLATES.” 2012. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021.
http://hdl.handle.net/11244/319028.
MLA Handbook (7th Edition):
Bokalawela, Roshan S P. “NANO INTEGRATED LITHIUM POLYMER ELECTROLYTES BASED ON ANODIC ALUMINUM OXIDE (AAO) TEMPLATES.” 2012. Web. 27 Feb 2021.
Vancouver:
Bokalawela RSP. NANO INTEGRATED LITHIUM POLYMER ELECTROLYTES BASED ON ANODIC ALUMINUM OXIDE (AAO) TEMPLATES. [Internet] [Doctoral dissertation]. University of Oklahoma; 2012. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/11244/319028.
Council of Science Editors:
Bokalawela RSP. NANO INTEGRATED LITHIUM POLYMER ELECTROLYTES BASED ON ANODIC ALUMINUM OXIDE (AAO) TEMPLATES. [Doctoral Dissertation]. University of Oklahoma; 2012. Available from: http://hdl.handle.net/11244/319028

University of Oklahoma
2.
Lotfi, Hossein.
Interband Cascade Structures for Infrared Photodetectors and Thermophotovoltaic Devices.
Degree: PhD, 2016, University of Oklahoma
URL: http://hdl.handle.net/11244/47113
► Interband cascade (IC) devices are a family of quantum engineered heterostructures that include: IC lasers (ICLs), IC infrared photodetectors (ICIPs) and IC thermophotovoltaic (ICTPV) devices.…
(more)
▼ Interband cascade (IC) devices are a family of quantum engineered heterostructures that include: IC lasers (ICLs), IC infrared photodetectors (ICIPs) and IC thermophotovoltaic (ICTPV) devices. In these structures, the transport of carriers across different stages is made possible by the type-II broken-gap band alignment between InAs and GaSb. Many shortcomings in conventional single absorber narrow-bandgap devices, such as short carrier lifetime and limited diffusion length (particularly at high temperatures) can be addressed by a multiple-stage architecture. While multiple photons need to be absorbed to output one electron in a multi-stage detector or photovoltaic cell, the multiple-stage architecture has some big benefits, especially at high temperatures and long wavelengths. The multiple excitations (depending on the number of stages) of each electron in an ICIP result in lower noise (higher signal-to-noise) than conventional single-stage detectors with thick absorbers. Furthermore, by keeping individual absorbers shorter than the minority carrier diffusion length most of the photogenerated carriers can be collected. This efficient collection of photogenerated carriers along with the high open-circuit voltages lead to high conversion efficiencies in ICTPV devices. The theoretical and experimental exploration of these properties of ICIPs and ICTPV devices are the main focus of this dissertation.
Design and characterization of ICIPs in different bands including short- through very long-wavelength IR are discussed in detail. It is shown that a multiple-stage detector has superior performance over a single-stage detector at high temperatures.
In contrast to single-stage detectors, in ICIPs high-frequency bandwidths can be achieved with no compromise on the device sensitivity. The high-frequency modeling and characterization of ICIPs reveal gigahertz bandwidth (~1.3 GHz) with high detectivity (˃1E9 cm.Hz1/2/W) for three-stage mid-IR ICIPs at 300 K. A comparative study of time domain characteristics (i.e., eye diagrams) of single-stage detectors and ICIPs (with the total absorber thickness equal to that of the single-stage devices) confirmed the higher bandwidth and shorter fall and rise times in ICIPs.
The unidirectional flow of carriers in IC lasers makes their structure feasible for infrared detection. Therefore, it is possible to realize monolithically integrated lasers and detectors on a single chip. Since the detector section is edge-illuminated in these bi-functional devices, detectivities higher than 1E10 cm.Hz1/2/W were estimated for these detectors at room temperature (RT). High-detectivity and high-speed ICIPs along with low power consumption ICLs make monolithically integrated IC lasers and detectors a practical choice for compact spectrometers and lab-on-a-chip devices.
Two sets of ICTPV devices (Eg < 0.5 eV) were investigated to understand the influence of number of stages/absorber thickness on the TPV cells performance. Efficiencies up to ~10% were achieved in three-stage ICTPVs with 0.41 eV bandgap.…
Advisors/Committee Members: Yang, Rui Q. (advisor), Johnson, Matthew B. (committee member), Shi, Zhisheng (committee member), Cruz, J. R. (committee member), Sellers, Ian R. (committee member).
Subjects/Keywords: Optoelectronics; Infrared; Photodetectors; Thermophotovoltaic
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APA (6th Edition):
Lotfi, H. (2016). Interband Cascade Structures for Infrared Photodetectors and Thermophotovoltaic Devices. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/47113
Chicago Manual of Style (16th Edition):
Lotfi, Hossein. “Interband Cascade Structures for Infrared Photodetectors and Thermophotovoltaic Devices.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021.
http://hdl.handle.net/11244/47113.
MLA Handbook (7th Edition):
Lotfi, Hossein. “Interband Cascade Structures for Infrared Photodetectors and Thermophotovoltaic Devices.” 2016. Web. 27 Feb 2021.
Vancouver:
Lotfi H. Interband Cascade Structures for Infrared Photodetectors and Thermophotovoltaic Devices. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/11244/47113.
Council of Science Editors:
Lotfi H. Interband Cascade Structures for Infrared Photodetectors and Thermophotovoltaic Devices. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/47113

University of Oklahoma
3.
Rassel, SM Shazzad.
CHARACTERIZATION AND DEVELOPMENT OF SEMICONDUCTOR CASCADE DEVICES.
Degree: PhD, 2018, University of Oklahoma
URL: http://hdl.handle.net/11244/299799
► Interband cascade lasers (ICLs) are efficient source of mid-infrared light for many applications that require low power consumption and continuous wave (cw) operation at room…
(more)
▼ Interband cascade lasers (ICLs) are efficient source of mid-infrared light for many applications that require low power consumption and continuous wave (cw) operation at room temperature. In the last decade, remarkable progress has been made in developing ICLs on GaSb substrates, mainly in the 3 to 4μm wavelength region, but room temperature (RT) cw operation at the longer wavelength region beyond 6μm has not been achieved. Based on the characterization of earlier grown ICLs, InAs-based plasmon-waveguide ICLs were designed and fabricated to achieve improved performance near or beyond 6μm. These lasers were extensively characterized, investigated and analyzed in terms of various performance features and compared to other state-of-the-art lasers. One laser demonstrated a threshold current density (Jth) as low as 333A/cm2 at 300K for emission at 6003nm. This Jth is the lowest ever reported for a mid-infrared semiconductor laser in this wavelength range. These ICLs lased at temperatures up to 293K in cw mode and up to 357K in pulsed mode. A narrow-ridge laser operated in cw at 293K with a threshold input power as low as 0.66W, and was able to generate 3mW/facet output power at 280K, without accounting for beam divergence loss. These results are very encouraging examples of efficient ICLs at long wavelengths with low power consumption.
To investigate the quality of the laser beam of these InAs-based ICLs, the far-field patterns were studied and analyzed for both broad-area and narrow-ridge geometries. In the growth direction, near diffraction-limited single-mode beams were obtained. As expected, multi-mode lasing was observed in the lateral direction because the stripe widths were much longer than the lasing wavelength. Also, as expected, these multi-modes were found to be dependent on applied bias current. These far-field profiles were compared to simulations and reasonable agreement was obtained. Beam propagation factors were plotted against the laser stripe sizes and the values were found close to unity along the growth direction -indicating better beam quality, and below 18 along lateral direction -indicating room for improvement. This methodology can be applied to previously fabricated ICLs to better understand their beam optics.
In a related research project, single mode operation of ICLs was obtained by designing and fabricating a cleaved-coupled-cavity (CCC) laser. In our case, rather than cleaving to fabricate two cavities, we successfully demonstrated two ion-milling recipes, using a focused ion beam (FIB) to fabricate our CCC lasers. One recipe separated the two sections of CCC lasers electrically and the other recipe milled a narrow slot (air-gap) into the mesa. Based on the optical power from the fabricated cavities, the quality of the milled facet was found to be comparable to that of an as-cleaved facet. This CCC laser demonstrated a single mode operation at ~3109nm at room temperature with a reasonable side-mode-suppression-ratio (SMSR) of 24dB. A continuous tuning range of ~1.1nm and…
Advisors/Committee Members: Yang, Rui (advisor), Johnson, Matthew (committee member), Santos, Michael (committee member), Sigmarsson, Hjalti (committee member), Fulton, Caleb (committee member).
Subjects/Keywords: interband cascade laser; high-frequency; coupled cavity laser; far field beam; carrier transport
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Rassel, S. S. (2018). CHARACTERIZATION AND DEVELOPMENT OF SEMICONDUCTOR CASCADE DEVICES. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/299799
Chicago Manual of Style (16th Edition):
Rassel, SM Shazzad. “CHARACTERIZATION AND DEVELOPMENT OF SEMICONDUCTOR CASCADE DEVICES.” 2018. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021.
http://hdl.handle.net/11244/299799.
MLA Handbook (7th Edition):
Rassel, SM Shazzad. “CHARACTERIZATION AND DEVELOPMENT OF SEMICONDUCTOR CASCADE DEVICES.” 2018. Web. 27 Feb 2021.
Vancouver:
Rassel SS. CHARACTERIZATION AND DEVELOPMENT OF SEMICONDUCTOR CASCADE DEVICES. [Internet] [Doctoral dissertation]. University of Oklahoma; 2018. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/11244/299799.
Council of Science Editors:
Rassel SS. CHARACTERIZATION AND DEVELOPMENT OF SEMICONDUCTOR CASCADE DEVICES. [Doctoral Dissertation]. University of Oklahoma; 2018. Available from: http://hdl.handle.net/11244/299799

University of Oklahoma
4.
Jiang, Yuchao.
High-performance InAs-based interband cascade lasers.
Degree: PhD, 2016, University of Oklahoma
URL: http://hdl.handle.net/11244/34604
► Currently, there are only two types of mid-infrared lasers that are capable of continuous-wave (CW) operation above room temperature: quantum cascade (QC) lasers and interband…
(more)
▼ Currently, there are only two types of mid-infrared lasers that are capable of continuous-wave (CW) operation above room temperature: quantum cascade (QC) lasers and interband cascade (IC) lasers. Both of them share the cascade feature for carrier recycling. The most successful QC lasers, based on the inter-subband transition and the well-established InGaAs/InAlAs/InP material system, are able to deliver several watts of optical power. In contrast, IC lasers, based on the interband transition and the unique InAs/GaSb/AlSb type-II broken-bandgap material system, have the threshold power density more than an order of magnitude lower than that of QC lasers (e.g., 0.3 kW/cm2 vs. 11 kW/cm2). As a result, IC lasers become a better solution for low-power applications in the mid-infrared region.
GaSb-based IC lasers have achieved the best performance around 3.7 μm with a threshold current density as low as 100 A/cm2 at 300 K. However, their waveguide cladding layers, consisting of thick InAs/AlSb superlattice, have a low thermal conductivity and are challenging to grow by molecular beam epitaxy. These problems become more severe at longer lasing wavelengths due to the requirement of thicker cladding layers. InAs-based IC lasers, utilizing highly doped InAs as the optical cladding layer, have been developed to address these issues. The goal of this dissertation is to use modeling and experiments to explore several aspects of InAs-based IC lasers, including far-field patterns, high-temperature operation, long-wavelength operation, wide-tunability, and single frequency mode operation.
The beam quality is critical for the laser application. The higher-order spatial modes naturally appear when the laser ridge is wider than the lasing wavelength in the medium. For InAs-based IC lasers with a thin top cladding layer, the top contact configuration can have a major influence on the spatial modes, which are observed in the measurement of far-field patterns. The physical origin is identified by waveguide modeling based on an effective index method.
Radical design innovations, including “shortened injector” and “carrier rebalancing,” have significantly improved the performance of both GaSb-based and InAs-based IC lasers. Furthermore, a hybrid waveguide, consisting of an inner cladding layer with InAs/AlSb superlattice and an outer cladding layer with highly doped InAs, has significantly increased the modal gain of InAs-based IC lasers. As a result, CW operations above room temperature have been achieved at wavelengths of 4.6~4.8 μm. The threshold current density, 247 A/cm2 at 300 K in pulsed mode, is the lowest ever reported among the mid-infrared semiconductor lasers at similar wavelengths. The pulsed operating temperature is as high as 377 K.
Long-wavelength operations are vigorously explored. With the hybrid waveguide mentioned above, the lasing temperature reaches 324 K at a wavelength of 6.4 μm. Further design improvement and optimization are presented. In addition, the lasing wavelength is extended to 11.2 μm at 130 K.…
Advisors/Committee Members: Yang, Rui (advisor), Santos, Michael (committee member), Shi, Zhisheng (committee member), Johnson, Matthew (committee member), Sluss, James (committee member).
Subjects/Keywords: semiconductor lasers; interband cascade; mid-infrared
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Jiang, Y. (2016). High-performance InAs-based interband cascade lasers. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/34604
Chicago Manual of Style (16th Edition):
Jiang, Yuchao. “High-performance InAs-based interband cascade lasers.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021.
http://hdl.handle.net/11244/34604.
MLA Handbook (7th Edition):
Jiang, Yuchao. “High-performance InAs-based interband cascade lasers.” 2016. Web. 27 Feb 2021.
Vancouver:
Jiang Y. High-performance InAs-based interband cascade lasers. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/11244/34604.
Council of Science Editors:
Jiang Y. High-performance InAs-based interband cascade lasers. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/34604

University of Oklahoma
5.
Lei, Lin Jr.
Mid-wavelength and long-wavelength interband cascade infrared photodetectors.
Degree: PhD, 2017, University of Oklahoma
URL: http://hdl.handle.net/11244/52405
► Interband cascade (IC) devices are a family of infrared optoelectronic devices that includes interband cascade lasers (ICLs), interband cascade infrared photodetectors (ICIPs) and interband cascade…
(more)
▼ Interband cascade (IC) devices are a family of infrared optoelectronic devices that includes interband cascade lasers (ICLs), interband cascade infrared photodetectors (ICIPs) and interband cascade infrared thermophotovoltaics (ICTPVs). They are unique due to their multiple-stage architecture based on type-II heterostructures. In IC devices, the carrier transport is rectified with two unipolar barriers (injectors), namely the electron barrier (hole injector) and hole barrier (electron injector). The series connection between cascade stages is realized by employing the type-II broken-gap alignment between InAs and GaSb layers. While a conventional single stage detector is limited by the short diffusion length and carrier lifetime at high temperatures and long wavelengths, an ICIP with a series of thin discrete absorbers can circumvent these limitations with high device performance. Although the responsivity of ICIPs is reduced by the thin absorbers, noise is also reduced significantly by the series connected cascade stages so that a large signal to noise ratio is retained. Most of the interest for IR detector applications is focused on the mid-wavelength (MW) infrared (IR) and long-wavelength (LW) IR bands. However, most of them require a cooling system to achieve high device performance. ICIPs are one of the most promising candidates for meeting the high-performance and uncooled requirements of these applications.
MW ICIPs based on InAs/GaSb type-II superlattice (T2SL) and bulk GaInAsSb absorbers are discussed in detail. High temperature operation and high device performance are demonstrated with
Johnson-noise limited detectivities over 1.0×10
9 cmˑHz
1/2/W at 300 K.
LW ICIPs with current-matching and non-current matching architectures were systematically studied. These ICIPs are capable of operating at high temperatures up to 340 K. They exhibited a high device performance with a detectivity (D*) higher than 1.0×10
9 and 1.0×10
8 cmˑHz
1/2/W at 200 and 300 K, respectively. While current-matching is necessary for maximizing photon absorption to achieve optimal responsivity, the lower responsivity in the non-current matched ICIPs is attributed to light attenuation in the optically deeper stages. Meanwhile, the responsivity in the non-current matched ICIPs is enhanced by the significantly higher electrical gain, along with the much higher resistances, so that their device performance is comparable or even slightly higher than the current matched ICIPs.
Multi-stage ICIPs show superior performance over conventional one-stage detectors at high temperatures in both the MWIR and LWIR regions. The presence of high electrical gain in the both MW and LW ICIPs may be related to two mechanisms: one is the photoconductive gain due to a shorter transit time than carrier lifetime, the other is the compensation of dark current to maintain current continuity.
The observed multiple negative differential conductance (NDC) features in the LW ICIPs at high temperatures are related to the sequential turn-off of intraband…
Advisors/Committee Members: Yang, Rui Q. Jr (advisor), Santos, Michael Jr (committee member), Johnson, Matthew Jr (committee member), Mullen, Kieran Jr (committee member), Kao, Chung Jr (committee member), Sigmarsson, Hjalti Jr (committee member).
Subjects/Keywords: infrared detectors; interband cascade; mid-wavelength and long wavelength; high operating temperature
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lei, L. J. (2017). Mid-wavelength and long-wavelength interband cascade infrared photodetectors. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/52405
Chicago Manual of Style (16th Edition):
Lei, Lin Jr. “Mid-wavelength and long-wavelength interband cascade infrared photodetectors.” 2017. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021.
http://hdl.handle.net/11244/52405.
MLA Handbook (7th Edition):
Lei, Lin Jr. “Mid-wavelength and long-wavelength interband cascade infrared photodetectors.” 2017. Web. 27 Feb 2021.
Vancouver:
Lei LJ. Mid-wavelength and long-wavelength interband cascade infrared photodetectors. [Internet] [Doctoral dissertation]. University of Oklahoma; 2017. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/11244/52405.
Council of Science Editors:
Lei LJ. Mid-wavelength and long-wavelength interband cascade infrared photodetectors. [Doctoral Dissertation]. University of Oklahoma; 2017. Available from: http://hdl.handle.net/11244/52405

University of Oklahoma
6.
Larson, Preston.
Fabrication and characterization of ordered arrays of nanostructures.
Degree: PhD, Homer L. Dodge Department of Physics and Astronomy, 2005, University of Oklahoma
URL: http://hdl.handle.net/11244/893
► Nanostructures are currently of great interest because of their unique properties and potential applications in a wide range of areas such as opto-electronic and biomedical…
(more)
▼ Nanostructures are currently of great interest because of their unique properties and potential applications in a wide range of areas such as opto-electronic and biomedical devices. Current research in nanotechnology involves fabrication and characterization of these structures, as well as theoretical and experimental studies to explore their unique and novel properties. Not only do nanostructures have the potential to be both evolutionary (state-of-the-art ICs have more and more features on the nanoscale) but revolutionary (quantum computing) as well.
Advisors/Committee Members: Johnson, Matthew B., (advisor).
Subjects/Keywords: Nanostructures.; Nanotechnology.; Physics, Condensed Matter.
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APA ·
Chicago ·
MLA ·
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Export
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APA (6th Edition):
Larson, P. (2005). Fabrication and characterization of ordered arrays of nanostructures. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/893
Chicago Manual of Style (16th Edition):
Larson, Preston. “Fabrication and characterization of ordered arrays of nanostructures.” 2005. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021.
http://hdl.handle.net/11244/893.
MLA Handbook (7th Edition):
Larson, Preston. “Fabrication and characterization of ordered arrays of nanostructures.” 2005. Web. 27 Feb 2021.
Vancouver:
Larson P. Fabrication and characterization of ordered arrays of nanostructures. [Internet] [Doctoral dissertation]. University of Oklahoma; 2005. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/11244/893.
Council of Science Editors:
Larson P. Fabrication and characterization of ordered arrays of nanostructures. [Doctoral Dissertation]. University of Oklahoma; 2005. Available from: http://hdl.handle.net/11244/893

University of Oklahoma
7.
Curits, Mark Erman.
High-Resolution Transmission Electron Microscopy Analysis of Nanostructures.
Degree: PhD, 2009, University of Oklahoma
URL: http://hdl.handle.net/11244/319354
► Nanostructures are of great interest because of the unique size range they occupy between the bulk and the quantum regimes. Characterizing nanostructures requires tools that…
(more)
▼ Nanostructures are of great interest because of the unique size range they occupy between the bulk and the quantum regimes. Characterizing nanostructures requires tools that can access this size regime. Transmission electron microscopy (TEM) is one of the most important tools used to study materials and structures on the nanoscale because of its high-resolution imaging capabilities and the number of different characterization techniques that one single instrument can perform. In this dissertation, the characterization of several types of nanostructures using TEM and TEM-based techniques is described in detail. These techniques are used in conjunction with other nanoscale characterization methods such as AFM, XRD, and SEM to obtain a more complete understanding of the structures being studied.
Advisors/Committee Members: Johnson, Matthew (advisor).
Subjects/Keywords: Nanostructures; Transmission electron microscopy
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Curits, M. E. (2009). High-Resolution Transmission Electron Microscopy Analysis of Nanostructures. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/319354
Chicago Manual of Style (16th Edition):
Curits, Mark Erman. “High-Resolution Transmission Electron Microscopy Analysis of Nanostructures.” 2009. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021.
http://hdl.handle.net/11244/319354.
MLA Handbook (7th Edition):
Curits, Mark Erman. “High-Resolution Transmission Electron Microscopy Analysis of Nanostructures.” 2009. Web. 27 Feb 2021.
Vancouver:
Curits ME. High-Resolution Transmission Electron Microscopy Analysis of Nanostructures. [Internet] [Doctoral dissertation]. University of Oklahoma; 2009. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/11244/319354.
Council of Science Editors:
Curits ME. High-Resolution Transmission Electron Microscopy Analysis of Nanostructures. [Doctoral Dissertation]. University of Oklahoma; 2009. Available from: http://hdl.handle.net/11244/319354
8.
Ye, Hao.
Molecular Beam Epitaxy of InAs, GaSb, AlSb Structures for Interband Cascade Devices.
Degree: PhD, 2016, University of Oklahoma
URL: http://hdl.handle.net/11244/34898
► The interband cascade (IC) family of devices has been extended beyond mid-infrared lasers to include photovoltaic (PV) and photodetector (PD) devices. These devices utilize the…
(more)
▼ The interband cascade (IC) family of devices has been extended beyond mid-infrared lasers to include photovoltaic (PV) and photodetector (PD) devices. These devices utilize the transition between conduction and valence bands for photon emission or absorption in the infrared region. The cascade structure recycles electrons to generate or collect multiple photons per electron. Epitaxial growths of the device structures are challenging because they consist of hundreds of quantum wells and require atomic layer precision in thickness control. Molecular beam epitaxy (MBE) was used to grow these structures with InAs, GaSb, AlSb, and their alloys on InAs or GaSb substrates.
IC laser structures with InAs plasmon cladding layers were grown on InAs substrates for wavelengths greater than 3 μm. To provide a smooth initial surface for the cascade region, the optimal conditions for growth of homoepitaxial InAs layers were investigated over a wide range of substrate temperatures and As2/In flux ratios at a growth rate of 0.66 monolayer/s (ML/s). Material quality was investigated using differential interference contrast microscopy, scanning electron microscopy, and atomic force microscopy. The geometry of oval hillock defects on the InAs layers suggested that these defects originated at the substrate surface. The InAs-based IC lasers had emission wavelengths out to 11 μm, which is the longest wavelength among interband lasers based on III–V materials. By introducing intermediate superlattice (SL) cladding layers to enhance optical confinement and reduce internal absorption loss, the first continuous wave operation of InAs-based IC lasers at room temperature was demonstrated. The threshold current density of 247 A/cm2 for emission near 4.6 μm is the lowest ever reported among semiconductor mid-infrared lasers at similar wavelengths.
ICPV and ICPD devices were developed based on the architecture of IC lasers. They both consist of multiple discrete InAs/GaSb SL absorbers sandwiched between electron and hole barriers. ICPV devices can be used in thermophotovoltaic systems that convert radiant energy from a heat source into electricity. Strain-balanced InAs/GaSb SL structures were achieved by adjusting the group-V overpressure during MBE growth. Two- and three-stage ICPV devices operated at room temperature with substantial open-circuit voltages at a cutoff wavelength of 5.3 μm, the longest ever reported for room-temperature PV devices.
The interfaces of InAs/GaSb SLs were studied with the goal of improving the PDs designed for the long-wavelength infrared region. Two ICPD structures with different SL interfaces were grown by MBE, one with a ~1.2 ML-thick InSb layer inserted intentionally only at the GaSb-on-InAs interfaces and another with a ~0.6 ML-thick InSb layer inserted at both InAs-on-GaSb and GaSb-on-InAs interfaces. The material quality of the PD structures was similar according to differential interference contrast microscopy, atomic force microscopy, and x-ray diffraction measurements. The device performances were not…
Advisors/Committee Members: Yang, Rui (advisor), Santos, Michael (advisor), Murphy, Sheena (committee member), Ruyle, Jessica (committee member), Shi, Zhisheng (committee member), Johnson, Matthew (committee member).
Subjects/Keywords: Molecular Beam Epitaxy; III-V Semiconductor Material; Laser; Detector
…at the University of
Oklahoma [24]. There are several advantages of using the…
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ye, H. (2016). Molecular Beam Epitaxy of InAs, GaSb, AlSb Structures for Interband Cascade Devices. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/34898
Chicago Manual of Style (16th Edition):
Ye, Hao. “Molecular Beam Epitaxy of InAs, GaSb, AlSb Structures for Interband Cascade Devices.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021.
http://hdl.handle.net/11244/34898.
MLA Handbook (7th Edition):
Ye, Hao. “Molecular Beam Epitaxy of InAs, GaSb, AlSb Structures for Interband Cascade Devices.” 2016. Web. 27 Feb 2021.
Vancouver:
Ye H. Molecular Beam Epitaxy of InAs, GaSb, AlSb Structures for Interband Cascade Devices. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/11244/34898.
Council of Science Editors:
Ye H. Molecular Beam Epitaxy of InAs, GaSb, AlSb Structures for Interband Cascade Devices. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/34898
.