Development of Indium Arsenide Quantum Well Electronic Circuits

Development of Indium Arsenide Quantum Well Electronic Circuits PDF Author: Joshua Bergman
Publisher:
ISBN:
Category : Indium arsenide
Languages : en
Pages :

Get Book Here

Book Description
This dissertation focuses on the development of integrated circuits that employ InAs quantum well electronic devices. There are two InAs quantum well electronic devices studied in this work, the first being the pseudomorphic InAs/In0.53Ga0.47As/AlAs resonant tunneling diode (RTD) grown on an InP substrate, and the second being the InAs/AlSb HEMT. Because of there is no semi-insulating substrate near the InAs lattice constant of 6.06, this work develops monolithic and hybrid integration methods to realize integrated circuits. For the case of hybrid RTD circuits, a thin-film integration method was developed to integrate InAs/In0.53Ga0.47As/AlAs RTDs to prefabricated CMOS circuits, and this technique was employed to demonstrate a novel RTD-CMOS comparator. To achieve higher speed circuit operation, a next-generation RTD fabrication process was developed to minimize the parasitic capacitance associated with the thin-film hybridization process. This improved fabrication process is detailed and yield and uniformity analysis is included. Similar InP-based tunnel diodes can be integrated with InP-based HEMTs in monolithic RTD-HEMT integrated circuits, and in this work elementary microwave circuit components were characterized that co-integrate InP-based tunnel diodes with HEMTs. In the case of the InAs/AlSb HEMT, the monolithic approach grows the HEMT on a metamorphic buffer on a GaAs substrate. The semiconductor material and process development of the InAs/AlSb HEMT MMIC technology is described. The remarkable microwave and RF noise properties of the InAs/AlSb HEMT were characterized and analyzed, with special attention given to the strong effects of impact ionization in the narrow bandgap InAs channel. Results showed the extent to which impact ionization affects the small-signal gain and noise figure of the HEMT, and that these effects become less prevalent as the frequency of operation increases.

Development of Indium Arsenide Quantum Well Electronic Circuits

Development of Indium Arsenide Quantum Well Electronic Circuits PDF Author: Joshua Bergman
Publisher:
ISBN:
Category : Indium arsenide
Languages : en
Pages :

Get Book Here

Book Description
This dissertation focuses on the development of integrated circuits that employ InAs quantum well electronic devices. There are two InAs quantum well electronic devices studied in this work, the first being the pseudomorphic InAs/In0.53Ga0.47As/AlAs resonant tunneling diode (RTD) grown on an InP substrate, and the second being the InAs/AlSb HEMT. Because of there is no semi-insulating substrate near the InAs lattice constant of 6.06, this work develops monolithic and hybrid integration methods to realize integrated circuits. For the case of hybrid RTD circuits, a thin-film integration method was developed to integrate InAs/In0.53Ga0.47As/AlAs RTDs to prefabricated CMOS circuits, and this technique was employed to demonstrate a novel RTD-CMOS comparator. To achieve higher speed circuit operation, a next-generation RTD fabrication process was developed to minimize the parasitic capacitance associated with the thin-film hybridization process. This improved fabrication process is detailed and yield and uniformity analysis is included. Similar InP-based tunnel diodes can be integrated with InP-based HEMTs in monolithic RTD-HEMT integrated circuits, and in this work elementary microwave circuit components were characterized that co-integrate InP-based tunnel diodes with HEMTs. In the case of the InAs/AlSb HEMT, the monolithic approach grows the HEMT on a metamorphic buffer on a GaAs substrate. The semiconductor material and process development of the InAs/AlSb HEMT MMIC technology is described. The remarkable microwave and RF noise properties of the InAs/AlSb HEMT were characterized and analyzed, with special attention given to the strong effects of impact ionization in the narrow bandgap InAs channel. Results showed the extent to which impact ionization affects the small-signal gain and noise figure of the HEMT, and that these effects become less prevalent as the frequency of operation increases.

(Indium, Gallium)arsenide Quantum Dot Materials for Solar Cell Applications

(Indium, Gallium)arsenide Quantum Dot Materials for Solar Cell Applications PDF Author: Anup Pancholi
Publisher: ProQuest
ISBN: 9780549924562
Category : Gallium arsenide
Languages : en
Pages :

Get Book Here

Book Description
The last few years have seen rapid advances in nanoscience and nanotechnology, allowing unprecedented manipulation of nanostructures controlling solar energy capture, conversion, and storage. Quantum confined nanostructures, such as quantum wells (QWs) and quantum dots (QDs) have been projected as potential candidates for the implementation of some high efficiency photovoltaic device concepts, including the intermediate band solar cell (IBSC). In this dissertation research, we investigated multiple inter-related themes, with the main objective of providing a deeper understanding of the physical and optical properties of QD structures relevant to the IBSC concept. These themes are: (i) Quantum engineering and control of energy levels in QDs, via a detailed study of the electronic coupling in multilayer QD structures; (ii) Controlled synthesis of well-organized, good quality, high volume density, and uniform-size QD arrays, in order to maximize the absorption efficiency and to ensure the coupling between the dots and the formation of the minibands; and (iii) Characterization of carrier dynamics and development of techniques to enhance the charge transport and efficient light harvesting. A major issue in a QD-based IBSC is the occurrence of charge trapping, followed by recombination in the dots, which results in fewer carriers being collected and hence low quantum efficiency. In order to collect most of the light-generated carriers, long radiative lifetimes, higher mobilities, and a lower probability of non-radiative recombination events in the solar cell would be desirable. QD size-dependent radiative lifetime and electronic coupling in multilayer QD structures were studied using photoluminescence (PL) and time-resolved photoluminescence (TRPL). For the uncoupled QD structures with thick barriers between the adjacent QD layers, the radiative lifetime was found to increase with the QD size, which was attributed to increased oscillator strength in smaller size dots. On the other hand, in the sample with thin barrier and electronically coupled QDs, the radiative lifetime increases and later decreases with the dot size. This is due to the enhancement of the oscillator strength in the larger size, coherently coupled QDs. In order to improve the quality of multi-layer QD structures, strain compensated barriers were introduced between the QD layers grown on off-oriented GaAs (311)B substrate. The QD shape anisotropy resulted from the growth on off-oriented substrate was studied using polarization-dependent PL measurements both on the surface and the edge of the samples. The transverse electric mode of the edge-emitted PL showed about 5° deviation from the sample surface for the dots grown on (311)B GaAs, which was attributed to the tilted vertical alignment and the shape asymmetry of dots resulted from the substrate orientation. Significant structural quality improvements were attained by introducing strain compensated barriers, i.e., reduction of misfit dislocations and uniform dot size formation. Longer lifetime (~1 ns) and enhanced PL intensity at room temperature were obtained, compared to those in conventional multilayer (In, Ga)As/GaAs QD structures. A significant increase in the open circuit voltage (V oc) was observed for the solar cell devices fabricated with the strain compensated structures. A major issue in a QD IBSC is the occurrence of charge trapping, followed by recombination in the dots, which results in fewer carriers being collected, and hence low quantum efficiency. We proposed and studied a novel structure, in which InAs QDs were sandwiched between GaAsSb (12% Sb) strain-reducing layers (SRLs) with various thicknesses. Both short (~1 ns) and long (~4-6 ns) radiative lifetimes were measured in the dots and were attributed to type-I and type-II transitions, respectively, which were induced by the band alignment modifications at the QD/barrier interface in the structures analyzed, due to the quantum confinement effect resulting from different GaAsSb barrier thicknesses. Based on our findings, a structure with type-II QD/barrier interface with relatively long radiative recombination lifetime may be a viable candidate in designing IBSC.

Electrical Properties of Indium Arsenide Nanowires and Their Field-Effect Transistors

Electrical Properties of Indium Arsenide Nanowires and Their Field-Effect Transistors PDF Author: Mengqi Fu
Publisher: Springer
ISBN: 9811334447
Category : Science
Languages : en
Pages : 113

Get Book Here

Book Description
This book explores the impacts of important material parameters on the electrical properties of indium arsenide (InAs) nanowires, which offer a promising channel material for low-power electronic devices due to their small bandgap and high electron mobility. Smaller diameter nanowires are needed in order to scale down electronic devices and improve their performance. However, to date the properties of thin InAs nanowires and their sensitivity to various factors were not known. The book presents the first study of ultrathin InAs nanowires with diameters below 10 nm are studied, for the first time, establishing the channel in field-effect transistors (FETs) and the correlation between nanowire diameter and device performance. Moreover, it develops a novel method for directly correlating the atomic-level structure with the properties of individual nanowires and their device performance. Using this method, the electronic properties of InAs nanowires and the performance of the FETs they are used in are found to change with the crystal phases (wurtzite, zinc-blend or a mix phase), the axis direction and the growth method. These findings deepen our understanding of InAs nanowires and provide a potential way to tailor device performance by controlling the relevant parameters of the nanowires and devices.

Dissertation Abstracts International

Dissertation Abstracts International PDF Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 780

Get Book Here

Book Description


Masters Theses in the Pure and Applied Sciences

Masters Theses in the Pure and Applied Sciences PDF Author: Wade H. Shafer
Publisher: Springer Science & Business Media
ISBN: 1461573947
Category : Science
Languages : en
Pages : 430

Get Book Here

Book Description
Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Oata Analysis and Synthesis (CINOAS) * at Purdue. University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 33 (thesis year 1988) a total of 13,273 theses titles from 23 Canadian and 1 85 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 33 reports theses submitted in 1988, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.

Virtual Synthesis of Nanosystems by Design

Virtual Synthesis of Nanosystems by Design PDF Author: Liudmila Pozhar
Publisher: Elsevier
ISBN: 0123972892
Category : Science
Languages : en
Pages : 383

Get Book Here

Book Description
This is the only book on a novel fundamental method that uses quantum many body theoretical approach to synthesis of nanomaterials by design. This approach allows the first-principle prediction of transport properties of strongly spatially non-uniform systems, such as small QDs and molecules, where currently used DFT-based methods either fail, or have to use empirical parameters. The book discusses modified algorithms that allow mimicking experimental synthesis of novel nanomaterials---to compare the results with the theoretical predictions--and provides already developed electronic templates of sub-nanoscale systems and molecules that can be used as components of larger materials/fluidic systems. - The only publication on quantum many body theoretical approach to synthesis of nano- and sub-nanoscale systems by design. - Novel and existing many-body field theoretical, computational methods are developed and used to realize the theoretical predictions for materials for IR sensors, light sources, information storage and processing, electronics, light harvesting, etc. Novel algorithms for EMD and NEMD molecular simulations of the materials' synthesis processes and charge-spin transport in synthesized systems are developed and described. - Includes the first ever models of Ni-O quantum wires supported by existing experimental data. - All-inclusive analysis of existing experimental data versus the obtained theoretical predictions and nanomaterials templates.

Chemical Abstracts

Chemical Abstracts PDF Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 2002

Get Book Here

Book Description


Intersubband Transitions in Quantum Wells: Physics and Device Applications

Intersubband Transitions in Quantum Wells: Physics and Device Applications PDF Author:
Publisher: Academic Press
ISBN: 0080864600
Category : Science
Languages : en
Pages : 323

Get Book Here

Book Description
Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The Willardson and Beer series, as it is widely known, has succeeded in producing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise that this tradition will be maintained and even expanded.Reflecting the truly interdisciplinary nature of the field that the series covers, the volumes in Semiconductors and Semimetals have been and will continue to be of great interest to physicists, chemists, materials scientists, and device engineers in modern industry.

Optical Characterization and Modeling of Compositionally Matched Indium Arsenide-Antimonide Bulk and Multiple Quantum Well Semiconductors

Optical Characterization and Modeling of Compositionally Matched Indium Arsenide-Antimonide Bulk and Multiple Quantum Well Semiconductors PDF Author: Scott C. Phillips
Publisher:
ISBN: 9781423516262
Category : Quantum electronics
Languages : en
Pages : 121

Get Book Here

Book Description
Indium arsenide-antimonide (InAsSb) semiconductors have been determined to emit in the 3-5 micrometer range, the window of interest for countermeasures against infrared electro-optical threats. This experiment set out to cross the bulk to quantum well characterization barrier by optically characterizing two sets of compositionally matched type I quantum well and bulk well material samples. Absorption measurements determined the band gap energy of the bulk samples and the first allowed subband transition for the quantum wells. By collecting absorption spectra at different temperatures, the trend of the energy transitions was described by fitting a Varshni equation to them. The expected result of the quantum well always having slightly higher energy than its bulk counterpart was observed. An etalon effect also was observed in the quantum wells, caused by the cladding layers in those samples. Photoluminescence spectra also were collected to characterize the change in electron temperature (Te) as the excitation power was varied. As expected, electron temperature increased with increasing power and increasing temperature. The start of the longitudinal optical phonon-dominated cooling range due to excitation intensity also was determined for the samples from 1/Te. It was found that the quantum well required higher excitation intensities to achieve this effect. Lastly, the energy transitions found for the quantum well samples were compared to those found by a finite element method model. The predicted energies all had a constant value above what was found experimentally, indicating the program had a translation error within it. (10 tables, 47 figures, 18 refs.)

Comprehensive Semiconductor Science and Technology

Comprehensive Semiconductor Science and Technology PDF Author:
Publisher: Newnes
ISBN: 0080932282
Category : Science
Languages : en
Pages : 3572

Get Book Here

Book Description
Semiconductors are at the heart of modern living. Almost everything we do, be it work, travel, communication, or entertainment, all depend on some feature of semiconductor technology. Comprehensive Semiconductor Science and Technology, Six Volume Set captures the breadth of this important field, and presents it in a single source to the large audience who study, make, and exploit semiconductors. Previous attempts at this achievement have been abbreviated, and have omitted important topics. Written and Edited by a truly international team of experts, this work delivers an objective yet cohesive global review of the semiconductor world. The work is divided into three sections. The first section is concerned with the fundamental physics of semiconductors, showing how the electronic features and the lattice dynamics change drastically when systems vary from bulk to a low-dimensional structure and further to a nanometer size. Throughout this section there is an emphasis on the full understanding of the underlying physics. The second section deals largely with the transformation of the conceptual framework of solid state physics into devices and systems which require the growth of extremely high purity, nearly defect-free bulk and epitaxial materials. The last section is devoted to exploitation of the knowledge described in the previous sections to highlight the spectrum of devices we see all around us. Provides a comprehensive global picture of the semiconductor world Each of the work's three sections presents a complete description of one aspect of the whole Written and Edited by a truly international team of experts