+publisher:"University of Oklahoma" +contributor:("Yang, Rui")

University of Oklahoma

1. Hinkey, Robert. MULTIPLE-STAGE INTERBAND CASCADE PHOTOVOLTAIC DEVICES USING 6.1 Å SEMICONDUCTOR MATERIALS.

Degree: PhD, 2013, University of Oklahoma

► Interband cascade photovoltaic (IC PV) structures are an attractive alternative to the conventional long-absorber diode structures currently used for mid-infrared photovoltaic devices. The unique feature… (more)

▼ Interband cascade photovoltaic (IC PV) structures are an attractive alternative to the conventional long-absorber diode structures currently used for mid-infrared photovoltaic devices. The unique feature of IC PV devices is that they utilize a multiple-stage architecture. This sort of design is made possible by the type-II broken-gap alignment between InAs and GaSb. In a multiple-stage device, electrons must be excited several times by above-bandgap photons in order to pass between the device contacts. Although counterintuitive, this transport feature can be beneficial for both energy-conversion and infrared detector technology. In particular, the interband cascade approach should be useful for improving the performance of narrow-bandgap optoelectronic devices operating at high temperature by ensuring a more efficient usage of the incident photons. The aim of this dissertation is to identify and demonstrate the advantages that interband cascade photovoltaic devices offer, both theoretically and experimentally. A theoretical framework for studying signal and noise in multiple-stage interband photovoltaic devices is presented. The theory flows from a general picture of electrons transitioning between thermalized reservoirs. Making the assumption of bulk-like absorbers, we show how the standard semiconductor transport and recombination equations can be extended to the case of multiple-stage devices. The electronic noise arising from fluctuations in the transition rates between reservoirs is derived using the Shockley-Ramo and Weiner-Khintchine theorems. This provides a unified noise treatment accounting for both the Johnson and shot noise. In this framework, we derive consistent analytic expressions for the quantum efficiency and thermal noise in terms of the design parameters and macroscopic material properties of the absorber. The theory is then applied in order to quantify the potential performance improvement that can be gained from the use of multiple stages. We show that multiple-stage detectors can achieve higher sensitivities for applications requiring a very fast temporal response. This is shown by deriving an expression for the optimal number of stages in terms of the absorption coefficient and absorber thicknesses for a multiple-stage detector with short absorbers. The multiple-stage architecture may also be useful for improving the sensitivity of high operating temperature detectors, if a short diffusion length limits the quantum efficiency. The potential sensitivity improvement offered by a multiple-stage architecture can be judged from the product of the absorption coefficient, α, and diffusion length, Ln, of the absorber material. For detector designs where the absorber lengths in each of the stages is equal, the multiple-stage architecture offers the potential for significant detectivity improvement when αLn ≤ 0.2. We also explore the potential of multiple-stage detectors with photocurrent-matched absorbers. In this architecture, the absorbers are designed to absorb and collect an… Advisors/Committee Members: Santos, Michael (advisor), Yang, Rui (committee member), Mullen, Kieran (committee member), Murphy, Sheena (committee member), Sigmarsson, Hjalti (committee member), Abraham, Eric (committee member).

Subjects/Keywords: Physics; Optics.

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APA (6^th Edition):

Hinkey, R. (2013). MULTIPLE-STAGE INTERBAND CASCADE PHOTOVOLTAIC DEVICES USING 6.1 Å SEMICONDUCTOR MATERIALS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/7906

Chicago Manual of Style (16^th Edition):

Hinkey, Robert. “MULTIPLE-STAGE INTERBAND CASCADE PHOTOVOLTAIC DEVICES USING 6.1 Å SEMICONDUCTOR MATERIALS.” 2013. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021. http://hdl.handle.net/11244/7906.

MLA Handbook (7^th Edition):

Hinkey, Robert. “MULTIPLE-STAGE INTERBAND CASCADE PHOTOVOLTAIC DEVICES USING 6.1 Å SEMICONDUCTOR MATERIALS.” 2013. Web. 27 Feb 2021.

Vancouver:

Hinkey R. MULTIPLE-STAGE INTERBAND CASCADE PHOTOVOLTAIC DEVICES USING 6.1 Å SEMICONDUCTOR MATERIALS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2013. [cited 2021 Feb 27]. Available from: http://hdl.handle.net/11244/7906.

Council of Science Editors:

Hinkey R. MULTIPLE-STAGE INTERBAND CASCADE PHOTOVOLTAIC DEVICES USING 6.1 Å SEMICONDUCTOR MATERIALS. [Doctoral Dissertation]. University of Oklahoma; 2013. Available from: http://hdl.handle.net/11244/7906

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 (6^th 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 (16^th 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 (7^th 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. Huang, Wenxiang. THERMOPHOTOVOLTAIC DEVICES AND INFRARED PHOTODETECTORS BASED ON INTERBAND CASCADE STRUCTURES.

Degree: PhD, 2020, University of Oklahoma

URL: http://hdl.handle.net/11244/324320

► Mid-infrared (IR) optoelectronic devices form the basis for many practical applications such as thermophotovoltaic (TPV) energy conversion, gas sensing, thermal imaging, medical diagnostics, free-space communications,… (more)

▼ Mid-infrared (IR) optoelectronic devices form the basis for many practical applications such as thermophotovoltaic (TPV) energy conversion, gas sensing, thermal imaging, medical diagnostics, free-space communications, infrared countermeasures and IR illumination. The mid-IR device family based on interband cascade (IC) structures includes IC lasers (ICLs), ICTPV cells and IC infrared photodetectors (ICIPs). These are special types of multistage devices whose operation is made possible by the unique properties of the 6.1 Å material system: InAs, GaSb and AlSb, and their related alloys. One of the key properties is the type-II broken-gap alignment between InAs and GaSb. In multistage ICTPV cells and ICIPs, electrons must undergo multiple interband excitations in order to travel between the electrical contacts. This means that the transport of a single electron requires multiple photons, which reverses the situation in ICLs where a single electron can generate multiple photons. Counterintuitively, this transport feature in ICTPV cells and ICIPs is conducive to improving device performance by enhancing the open-circuit voltage in ICTPV cells and suppressing the noise in ICIPs. Furthermore, the collection efficiency of photo-generated carriers in multistage IC devices can be significantly improved by thinning the absorbers in individual stages. Collectively, these advantages make IC structures an attractive choice for narrow bandgap optoelectronic devices, especially for operation at high temperatures. One focus of this dissertation is to outline and demonstrate the advantages provided by IC structures, both in theory and experiment. Another focus of this dissertation is to obtain a better understanding of the physics of IC devices and gain insights into their operation. Theoretical studies of single-absorber and multistage ICTPV cells are presented. The limitations in efficiency are understood by considering several important practical factors. These factors are identified to be closely associated with a short carrier lifetime, high dark saturation current density, small absorption coefficient, and limited diffusion length. The multistage IC architecture is shown to be able to overcome the diffusion length limitation that is responsible for the low quantum efficiency (QE) in single-absorber TPV cells. This ability of the IC architecture offers the opportunity to enhance conversion efficiency by about 10% for wide ranges of aL (product of absorption coefficient and diffusion length) and bandgaps, resulting in a particle conversion efficiency approaching 100%. The illustrated theoretical advantage of multistage IC structures is confirmed experimentally in a comparative study of three fabricated TPV devices, one with a single absorber and two that are multistage IC structures. The bandgap of the InAs/GaSb type-II superlattices (T2SLs) in the three devices is close to 0.2 eV at 300 K. The extracted collection efficiency is considerably higher in multistage IC devices than in the single-absorber device. To further… Advisors/Committee Members: Yang, Rui (advisor), Santos, Michael (committee member), Wang, Bin (committee member), Barboza, Bruno (committee member), Schwettmann, Arne (committee member), Mullen, Kieran (committee member).

Subjects/Keywords: Thermophotovoltaic cells; Infrared photodetectors; Interband cascade

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Huang, W. (2020). THERMOPHOTOVOLTAIC DEVICES AND INFRARED PHOTODETECTORS BASED ON INTERBAND CASCADE STRUCTURES. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/324320

Chicago Manual of Style (16^th Edition):

Huang, Wenxiang. “THERMOPHOTOVOLTAIC DEVICES AND INFRARED PHOTODETECTORS BASED ON INTERBAND CASCADE STRUCTURES.” 2020. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021. http://hdl.handle.net/11244/324320.

MLA Handbook (7^th Edition):

Huang, Wenxiang. “THERMOPHOTOVOLTAIC DEVICES AND INFRARED PHOTODETECTORS BASED ON INTERBAND CASCADE STRUCTURES.” 2020. Web. 27 Feb 2021.

Vancouver:

Huang W. THERMOPHOTOVOLTAIC DEVICES AND INFRARED PHOTODETECTORS BASED ON INTERBAND CASCADE STRUCTURES. [Internet] [Doctoral dissertation]. University of Oklahoma; 2020. [cited 2021 Feb 27]. Available from: http://hdl.handle.net/11244/324320.

Council of Science Editors:

Huang W. THERMOPHOTOVOLTAIC DEVICES AND INFRARED PHOTODETECTORS BASED ON INTERBAND CASCADE STRUCTURES. [Doctoral Dissertation]. University of Oklahoma; 2020. Available from: http://hdl.handle.net/11244/324320

University of Oklahoma

4. 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 (6^th 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 (16^th 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 (7^th 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

5. 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 (6^th 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 (16^th 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 (7^th 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

6. Sedlacek, Jonathon. MICROWAVE AND SURFACE ELECTROMETRY WITH RYDBERG ATOMS.

Degree: PhD, 2016, University of Oklahoma

URL: http://hdl.handle.net/11244/34363

► Measurements of microwave electric fields in rubidium vapor cells, and of static electric fields near quartz with cold rubidium are presented. The measurements are performed… (more)

Subjects/Keywords: Atom Physics; Ultracold Physics; Rydberg Atom Physics

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APA (6^th Edition):

Sedlacek, J. (2016). MICROWAVE AND SURFACE ELECTROMETRY WITH RYDBERG ATOMS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/34363

Chicago Manual of Style (16^th Edition):

Sedlacek, Jonathon. “MICROWAVE AND SURFACE ELECTROMETRY WITH RYDBERG ATOMS.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021. http://hdl.handle.net/11244/34363.

MLA Handbook (7^th Edition):

Sedlacek, Jonathon. “MICROWAVE AND SURFACE ELECTROMETRY WITH RYDBERG ATOMS.” 2016. Web. 27 Feb 2021.

Vancouver:

Sedlacek J. MICROWAVE AND SURFACE ELECTROMETRY WITH RYDBERG ATOMS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Feb 27]. Available from: http://hdl.handle.net/11244/34363.

Council of Science Editors:

Sedlacek J. MICROWAVE AND SURFACE ELECTROMETRY WITH RYDBERG ATOMS. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/34363

University of Oklahoma

7. Zhu, Zaifang. Resolving DNA Using A Bare Open Narrow Capillary without Sieving Matrix.

Degree: PhD, 2014, University of Oklahoma

URL: http://hdl.handle.net/11244/10445

► DNA molecules encode the hereditary information utilized in all living organisms, including humans. Separating DNA fragments is essential in biological research because it informs us… (more)

▼ DNA molecules encode the hereditary information utilized in all living organisms, including humans. Separating DNA fragments is essential in biological research because it informs us how DNA molecules work and eventually guides us to solve related problems based on DNA examinations. Agarose gel electrophoresis (AGE) and capillary gel electrophoresis (CGE) are the two most-widely used techniques for DNA separations. While these two techniques are capable of resolving DNA fragments nicely and efficiently, the use of viscous gels results in many issues, such as time-consuming gel preparation and tedious operations. To address these issues, our group recently developed a technique for gel-free DNA separations. As this technique was carried out in a bare narrow capillary and separations were majorly based on hydrodynamic chromatography, it was named Bare Narrow Capillary-Hydrodynamic Chromatography (BaNC-HDC). The objective of this dissertation is to develop a miniature and automatic BaNC-HDC system for rapid and high-throughput DNA separations without using any sieving matrix. We first proposed a new configuration of electroosmotic pumps (EOPs). In this new configuration, a basic EOP unit was composed of a +EOP and a –EOP. The pump capillaries used in +EOP were derivatized and the inner surface was positively charged. In –EOP, bare capillaries were used and the inner surface was negatively charged. In practice, high voltage was applied to the junction of +EOP and –EOP while both the inlet and outlet were grounded. With this configuration, we stacked ten open-capillary EOP units in series to boost the pressure, and a pumping pressure of up to 21.4 MPa was achieved. The performance of the constructed ten-unit EOP was evaluated by applying it to drive high performance liquid chromatography for separations of peptides or proteins. We then explored the resolving power of BaNC-HDC and presented the extremely high efficiency of BaNC-HDC for DNA separations. By manipulating the elution velocity, efficiency of more than one million theoretical plates per meter was easily obtained. Through studying the relationship between the elution velocity and the height equivalent to a theoretical plate, we revealed the unique behaviors of BaNC-HDC in van Deemter curves. The effect of temperature on DNA separations in BaNC-HDC was also investigated. In order to automate injections in BaNC-HDC, a microfabricated chip injector was developed. The chip injector was composed of an on-chip cross and an off-chip six-port valve, and it was able to deliver picoliters of sample reliably and reproducibly. By integrating this chip injector and the developed EOP into the BaNC-HDC system, the separation of GeneRulerTM 1-kbp plus DNA ladder was accomplished within five minutes and plasmid DNA was accurately sized. To improve throughput in BaNC-HDC, a splitting-based chip injector was developed. With the new injector, injections could be performed while the separation was in process, and this facilitated successive injections in BaNC-HDC.… Advisors/Committee Members: Liu, Shaorong (advisor), Richter-Addo, George (committee member), White, Robert (committee member), Yang, Zhibo (committee member), Yang, Rui (committee member).

Subjects/Keywords: Chemistry; Analytical.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Zhu, Z. (2014). Resolving DNA Using A Bare Open Narrow Capillary without Sieving Matrix. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/10445

Chicago Manual of Style (16^th Edition):

Zhu, Zaifang. “Resolving DNA Using A Bare Open Narrow Capillary without Sieving Matrix.” 2014. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021. http://hdl.handle.net/11244/10445.

MLA Handbook (7^th Edition):

Zhu, Zaifang. “Resolving DNA Using A Bare Open Narrow Capillary without Sieving Matrix.” 2014. Web. 27 Feb 2021.

Vancouver:

Zhu Z. Resolving DNA Using A Bare Open Narrow Capillary without Sieving Matrix. [Internet] [Doctoral dissertation]. University of Oklahoma; 2014. [cited 2021 Feb 27]. Available from: http://hdl.handle.net/11244/10445.

Council of Science Editors:

Zhu Z. Resolving DNA Using A Bare Open Narrow Capillary without Sieving Matrix. [Doctoral Dissertation]. University of Oklahoma; 2014. Available from: http://hdl.handle.net/11244/10445

University of Oklahoma

8. Johnson, Marcus. ASSESSMENT OF ONE-MOMENT AND TWO-MOMENT BULK MICROPHYSICS AND SPECTRAL BIN MICROPHYSICS SCHEMES USING IDEALIZED SUPERCELL SIMULATIONS AND REAL DATA CONVECTIVE-SCALE PREDICTIONS.

Degree: PhD, 2019, University of Oklahoma

URL: http://hdl.handle.net/11244/319577

► Optimal hydrometeor parameterization and their associated processes in microphysics schemes (both spectral bin and bulk) continue to evolve as these schemes attempt to match observed… (more)

▼ Optimal hydrometeor parameterization and their associated processes in microphysics schemes (both spectral bin and bulk) continue to evolve as these schemes attempt to match observed hydrometeor complexity. This dissertation spans several flavors of microphysics schemes: the one-moment Unified Model (UM), the partially-two moment Thompson and Morrison with one rimed ice category, the two-moment Milbrandt-Yau (MY2) and National Severe Storms Laboratory (NSSL) with two rimed ice categories, the Predicted Particle Properties (P3) with multiple mass assumptions within its ice particle size distributions (PSDs), and the spectral bin Hebrew University Cloud Model (HUCM). Microphysical performance (including their bias documentation) is examined in idealized supercell simulations by considering cloud ice and snow moment (and their associated budget) evolution, cloud ice and snow PSDs, low-level classic polarimetric radar signatures (ZDR arc and hail signature in the forward flank downdraft), and ice hydrometeor contoured frequency by altitude diagrams (CFADs). Two test cases over the Korean Peninsula (Changma front and Typhoon Sanba [2012]) are compared to S-band radar observations by applying a dual-polarization radar variable simulator to UM output. 2018 NOAA Hazardous Weather Testbed (HWT) Spring Experiment seasonal forecasts over much of the continental United States (CONUS) and four select convective line cases are both quantitatively and qualitatively compared to observed composite reflectivity, accumulated precipitation, and brightness temperature in the 11.2 μm channel for short-term (t = 1 – 6 forecast hours) and next-day (t = 12 – 36 forecast hours) forecasts. UM microphysics struggles to match observed dual-pol variables because of its one-moment parameterization of rain, specifically its rain PSD intercept parameter N0 diagnosis. As N0 varies inversely with rain mass, the scheme is producing too many small (large) drops in regions of too weak (intense) reflectivity. Both the fully two-moment MY2 and NSSL schemes are able to simulate a local maximum of ZDR near the forward flank edge and a gradual decrease in the direction of the deep-layer storm relative mean wind vector, but the large, dry hail in the MY2 scheme reduces ZDR on the edge of the supercell, while the NSSL’s ZDR arc is less elongated compared to typical observations. The P3 scheme with two ice categories is unable to simulate either signature, due to the restrictive rain and ice PSD slope Λ limiters (both directly and indirectly) preventing larger particles. In idealized supercell simulations, the HUCM and NSSL schemes simulate larger ice crystal moments than snow, while the Thompson scheme simulates more snow mass. This is due to the aggressive cloud ice to snow conversion in the scheme, which is intended given the assumed snow PSD. The flexible spectral bin HUCM PSDs simulate less small snow particles than the rigid bulk NSSL and Thompson schemes, but also sediments too large snow to the surface. Over the 2018 NOAA HWT Spring Experiment, the… Advisors/Committee Members: Xue, Ming (advisor), Jung, Youngsun (committee member), Homeyer, Cameron (committee member), Zhang, Guifu (committee member), Yang, Rui (committee member).

Subjects/Keywords: Microphysics; Numerical weather prediction; Convective-scale simulations

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APA (6^th Edition):

Johnson, M. (2019). ASSESSMENT OF ONE-MOMENT AND TWO-MOMENT BULK MICROPHYSICS AND SPECTRAL BIN MICROPHYSICS SCHEMES USING IDEALIZED SUPERCELL SIMULATIONS AND REAL DATA CONVECTIVE-SCALE PREDICTIONS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/319577

Chicago Manual of Style (16^th Edition):

Johnson, Marcus. “ASSESSMENT OF ONE-MOMENT AND TWO-MOMENT BULK MICROPHYSICS AND SPECTRAL BIN MICROPHYSICS SCHEMES USING IDEALIZED SUPERCELL SIMULATIONS AND REAL DATA CONVECTIVE-SCALE PREDICTIONS.” 2019. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021. http://hdl.handle.net/11244/319577.

MLA Handbook (7^th Edition):

Johnson, Marcus. “ASSESSMENT OF ONE-MOMENT AND TWO-MOMENT BULK MICROPHYSICS AND SPECTRAL BIN MICROPHYSICS SCHEMES USING IDEALIZED SUPERCELL SIMULATIONS AND REAL DATA CONVECTIVE-SCALE PREDICTIONS.” 2019. Web. 27 Feb 2021.

Vancouver:

Johnson M. ASSESSMENT OF ONE-MOMENT AND TWO-MOMENT BULK MICROPHYSICS AND SPECTRAL BIN MICROPHYSICS SCHEMES USING IDEALIZED SUPERCELL SIMULATIONS AND REAL DATA CONVECTIVE-SCALE PREDICTIONS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2019. [cited 2021 Feb 27]. Available from: http://hdl.handle.net/11244/319577.

Council of Science Editors:

Johnson M. ASSESSMENT OF ONE-MOMENT AND TWO-MOMENT BULK MICROPHYSICS AND SPECTRAL BIN MICROPHYSICS SCHEMES USING IDEALIZED SUPERCELL SIMULATIONS AND REAL DATA CONVECTIVE-SCALE PREDICTIONS. [Doctoral Dissertation]. University of Oklahoma; 2019. Available from: http://hdl.handle.net/11244/319577

University of Oklahoma

9. Wickramasinghe, Kaushini. MOLECULAR BEAM EPITAXY OF ANTIMONY QUANTUM WELLS FOR PROBING TOPOLOGICAL SURFACE STATES.

Degree: PhD, 2017, University of Oklahoma

URL: http://hdl.handle.net/11244/50910

► A topoelectronic transition was predicted for an Sb quantum well (QW) as a function of QW thickness. Bulk Sb is a semimetal with a negative… (more)

▼ A topoelectronic transition was predicted for an Sb quantum well (QW) as a function of QW thickness. Bulk Sb is a semimetal with a negative bandgap, with neither the conduction band minimum nor the valence band maximum at the Γ point. The Dirac point for the topological surface states is at the Γ point. In this dissertation, we present a detailed structural analysis of ultra-thin Sb QWs grown using a novel molecular beam epitaxy procedure that controls the thickness of the QW down to a few angstroms. Also, we studied the electronic properties of the topological surface states by suppressing the bulk conductivity through quantum confinement and enhancing the surface conductivity through remote n-type doping at the Γ point. Conductivity measurements on undoped QWs (0.7 to 6 nm thick) show a suppression of the bulk states, such that the surface conductivity is ~20% of the total conductivity for a 3.8 nm-thick QW. Interpretation of Hall-effect measurements, which nominally indicate p-type conduction for undoped QWs, was complicated by the presence of both electrons and holes. Therefore, we carried out experiments to populate the topological electron states by doping the GaSb barrier layer with tellurium (Te) atoms, creating donor states at the Γ point. At the Γ point of the QW, the topological electron states have a lower energy than any of the bulk conduction band minima. Remote n-doping of Sb QWs was confirmed by analyzing the spacer dependence of the Hall coefficients in a low magnetic field of 0 – 0.15 T and a temperature of 20 K. From high field magnetoresistance measurements, we deduced that holes still contributed significantly to the conductivity even though the Hall voltage indicated nominally n-type conduction. By further analyzing the fine features in the longitudinal resistance, we deduced that the surface states in a remotely-doped QW have an electron concentration of ~3.3×1012 cm-2 and a mobility of ~1600 – 2000 cm2/V·s. Assuming the initial electron concentration, before doping the Sb QW, is 2×1012 cm-2 (i.e. the lowest possible value estimated from theory), we calculated that the maximum amount transferred to the QW is ~1.3×1012 cm-2 when using GaSb barrier material and a Te-doping concentration of 1×1018 cm-3. The fine features that we interpreted as Shubnikov de Haas oscillations are of the order of the noise level; thus we cannot be certain of this interpretation. Therefore, we suggest future experiments to resolve this uncertainty. Advisors/Committee Members: Santos, Michael (advisor), Mullen, Kieran (committee member), Yang, Rui (committee member), Murphy, Sheena (committee member), Kao, Chung (committee member).

Subjects/Keywords: Molecular Beam Epitaxy growth and characterization; Topological Insulators

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wickramasinghe, K. (2017). MOLECULAR BEAM EPITAXY OF ANTIMONY QUANTUM WELLS FOR PROBING TOPOLOGICAL SURFACE STATES. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/50910

Chicago Manual of Style (16^th Edition):

Wickramasinghe, Kaushini. “MOLECULAR BEAM EPITAXY OF ANTIMONY QUANTUM WELLS FOR PROBING TOPOLOGICAL SURFACE STATES.” 2017. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021. http://hdl.handle.net/11244/50910.

MLA Handbook (7^th Edition):

Wickramasinghe, Kaushini. “MOLECULAR BEAM EPITAXY OF ANTIMONY QUANTUM WELLS FOR PROBING TOPOLOGICAL SURFACE STATES.” 2017. Web. 27 Feb 2021.

Vancouver:

Wickramasinghe K. MOLECULAR BEAM EPITAXY OF ANTIMONY QUANTUM WELLS FOR PROBING TOPOLOGICAL SURFACE STATES. [Internet] [Doctoral dissertation]. University of Oklahoma; 2017. [cited 2021 Feb 27]. Available from: http://hdl.handle.net/11244/50910.

Council of Science Editors:

Wickramasinghe K. MOLECULAR BEAM EPITAXY OF ANTIMONY QUANTUM WELLS FOR PROBING TOPOLOGICAL SURFACE STATES. [Doctoral Dissertation]. University of Oklahoma; 2017. Available from: http://hdl.handle.net/11244/50910

University of Oklahoma

10. 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 1.0×10⁹ cmˑHz¹/2/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 1.0×10⁹ and 1.0×10⁸ cmˑHz¹/2/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 (6^th 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 (16^th 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 (7^th 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

11. Esmaielpour, Hamidreza. TYPE-II QUANTUM WELL HOT CARRIER SOLAR CELLS.

Degree: PhD, 2018, University of Oklahoma

URL: http://hdl.handle.net/11244/316752

► Hot carrier solar cells are a third generation photovoltaic technology, which aims to increase power conversion efficiency of solar cells beyond the fundamental Shockley-Queisser limit… (more)

▼ Hot carrier solar cells are a third generation photovoltaic technology, which aims to increase power conversion efficiency of solar cells beyond the fundamental Shockley-Queisser limit (33%). A major source of loss in conventional solar cells is thermalization loss (heat generation), which occurs when photogenerated hot carriers lose their excess kinetic energy by interacting with phonons. Hot carrier solar cells have been proposed to reduce such thermalization losses if electron-phonon interactions can be inhibited. Despite significant recent progress in the field, there are still two significant challenges to overcome in order to design a practical hot carrier solar cell: 1) designing an efficient hot carrier absorber to inhibit hot carrier-phonon interactions; 2) develop energy selective contacts to extract hot carriers before thermalization occurs. Here, type-II InAs/AlAsSb quantum well (QW) structures are investigated as a promising candidate for hot carrier absorbers. Continuous wave power and temperature dependent photoluminescence spectroscopy and ultrafast transient absorption spectroscopy show evidence of robust hot carrier effects at low excitation powers and room temperature, which are significant properties when designing practical hot carrier solar cells. In addition, we have investigated accurate determination of the carrier temperature and phononic properties in the QW structures to provide a better understanding and fuller picture of the nature of hot carrier effects in these systems. Furthermore, we have designed and fabricated p-i-n diodes to study the electrical properties of hot carriers within practical InAs QW structures. As a result, through determination of the origin of hot carrier thermalization processes in the system it is possible to find ways to manipulate and/or control the hot carrier loss mechanisms for hot carrier solar cell or other optoelectronic applications. Finally, we have also investigated the optical spectroscopy of 2D hybrid lead halide perovskite structures for potential hot carrier solar cells. Advisors/Committee Members: Sellers, Ian R. (advisor), Santos, Michael B. (committee member), Barboza, Bruno U. (committee member), Yang, Rui Q. (committee member), Abraham, Eric R. I. (committee member).

Subjects/Keywords: Physics, Condensed Matter.; Photovoltaics Solar Cells; Photoluminescence Spectroscopy; Hot Carrier Effects

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Esmaielpour, H. (2018). TYPE-II QUANTUM WELL HOT CARRIER SOLAR CELLS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/316752

Chicago Manual of Style (16^th Edition):

Esmaielpour, Hamidreza. “TYPE-II QUANTUM WELL HOT CARRIER SOLAR CELLS.” 2018. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021. http://hdl.handle.net/11244/316752.

MLA Handbook (7^th Edition):

Esmaielpour, Hamidreza. “TYPE-II QUANTUM WELL HOT CARRIER SOLAR CELLS.” 2018. Web. 27 Feb 2021.

Vancouver:

Esmaielpour H. TYPE-II QUANTUM WELL HOT CARRIER SOLAR CELLS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2018. [cited 2021 Feb 27]. Available from: http://hdl.handle.net/11244/316752.

Council of Science Editors:

Esmaielpour H. TYPE-II QUANTUM WELL HOT CARRIER SOLAR CELLS. [Doctoral Dissertation]. University of Oklahoma; 2018. Available from: http://hdl.handle.net/11244/316752

12. 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 (6^th 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 (16^th 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 (7^th 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

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