You searched for +publisher:"University of Oklahoma" +contributor:("Johnson, Matthew").
Showing records 1 – 6 of
6 total matches.
No search limiters apply to these results.
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
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
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 August 21, 2019.
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. 21 Aug 2019.
Vancouver:
Bokalawela RSP. NANO INTEGRATED LITHIUM POLYMER ELECTROLYTES BASED ON ANODIC ALUMINUM OXIDE (AAO) TEMPLATES. [Internet] [Doctoral dissertation]. University of Oklahoma; 2012. [cited 2019 Aug 21].
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.
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
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
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 August 21, 2019.
http://hdl.handle.net/11244/34604.
MLA Handbook (7th Edition):
Jiang, Yuchao. “High-performance InAs-based interband cascade lasers.” 2016. Web. 21 Aug 2019.
Vancouver:
Jiang Y. High-performance InAs-based interband cascade lasers. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2019 Aug 21].
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
3.
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
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
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 August 21, 2019.
http://hdl.handle.net/11244/47113.
MLA Handbook (7th Edition):
Lotfi, Hossein. “Interband Cascade Structures for Infrared Photodetectors and Thermophotovoltaic Devices.” 2016. Web. 21 Aug 2019.
Vancouver:
Lotfi H. Interband Cascade Structures for Infrared Photodetectors and Thermophotovoltaic Devices. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2019 Aug 21].
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
4.
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.
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
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 August 21, 2019.
http://hdl.handle.net/11244/893.
MLA Handbook (7th Edition):
Larson, Preston. “Fabrication and characterization of ordered arrays of nanostructures.” 2005. Web. 21 Aug 2019.
Vancouver:
Larson P. Fabrication and characterization of ordered arrays of nanostructures. [Internet] [Doctoral dissertation]. University of Oklahoma; 2005. [cited 2019 Aug 21].
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
5.
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
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
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 August 21, 2019.
http://hdl.handle.net/11244/319354.
MLA Handbook (7th Edition):
Curits, Mark Erman. “High-Resolution Transmission Electron Microscopy Analysis of Nanostructures.” 2009. Web. 21 Aug 2019.
Vancouver:
Curits ME. High-Resolution Transmission Electron Microscopy Analysis of Nanostructures. [Internet] [Doctoral dissertation]. University of Oklahoma; 2009. [cited 2019 Aug 21].
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
6.
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…
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
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 August 21, 2019.
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. 21 Aug 2019.
Vancouver:
Ye H. Molecular Beam Epitaxy of InAs, GaSb, AlSb Structures for Interband Cascade Devices. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2019 Aug 21].
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
. 
Open Access Theses and Dissertations
