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  • Physical vapor deposition of novel thin-film solar absorbers

    Creator:
    Waters, Benjamin E.
    Abstract:
    Current leading thin-film solar cell technologies, i.e., cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS), employ elements which are either toxic (Cd), or rare and/or expensive (In, Te, Ga, and Cd). The aim of this thesis is to investigate new, abundant, non-toxic p-type semiconductors for potential solar absorber application....
    Resource Type:
    Masters Thesis
    Full Text:
    ] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.7 Energy band diagrams of (a) radiative, (b) Auger, and (c) Shockley- Read-Hall recombination

  • Assessment of High Mobility Oxide Thin-Film Transistors

    Creator:
    Stewart, Kevin A.
    Abstract:
    The trend towards higher resolution, faster refresh rate active-matrix liquid-crystal displays (AMLCDs) as well as the emergence of active-matrix organic light-emitting diode (AMOLED) displays is driving the demand for amorphous oxide semiconductor thin-film transistors (AOS TFTs) with higher mobility. A physics-based model for carrier transport in an amorphous semiconductor is...
    Resource Type:
    Dissertation
    Full Text:
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.11 Proposed AOS DOS model for (a) a-IGZO [6, 7] and (b) a-ZTO [8]. . 17 2.12 Hall mobility

  • Al-In-Sn-O thin-film transistors

    Creator:
    Stewart, Kevin A.
    Abstract:
    The aim of the research undertaken for this thesis was to develop a new high-performance amorphous oxide semiconductor (AOS) for use as a channel layer in a thin-film transistor (TFT). AOS TFTs offer higher electron mobility than the established amorphous silicon based technology. A new channel material comprised of aluminum...
    Resource Type:
    Masters Thesis
    Full Text:
    ). . . . . . . . . . . . . . . . 73 A.2 Hall measurements with the Van der Pauw method of 80 and 200 nm thick AITO films

  • Alternating-current thin-film electroluminescent device physics and modeling

    Creator:
    Douglas, Allan A.
    Abstract:
    Alternating-current thin-film electroluminescent (ACTFEL) devices are used in the formation of pixels in flat panel displays. ACTFEL flat panel displays have many advantages over other flat panel technologies. Specifically, ACTFEL panels are emissive displays, they have high brightness, wide viewing angles, and rugged construction. Although much is already known about...
    Resource Type:
    Masters Thesis
    Full Text:
    physics and modeling AN ABSTRACT OF THE THESIS OF Allan A. Douglas for the degree of Master of Science

  • Development of high efficiency solar absorbers

    Creator:
    Ravichandran, Ram
    Abstract:
    Current cadmium telluride and copper indium gallium diselenide thin-film solar cells (TFSCs) utilize thick absorbers (2 - 4 μm). For efficient carrier extraction in these TFSCs, the absorber layer requires high carrier mobilities and a long minority carrier lifetime, which necessitates the use of a high purity, defect-free thin film....
    Resource Type:
    Dissertation
    Full Text:
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 5.2 Hall measurement results from annealed FeS2 thin films. The films exhibit (a) carrier

  • Atomic solid state energy scale applied to novel thin-film solar absorbers

    Creator:
    Pelatt, Brian D.
    Abstract:
    The atomic solid state energy (SSE) scale is introduced as a tool for inorganic materials design. The SSE scale is obtained by assessing an average electron affinity (EA) (for a cation) or an average ionization potential (IP) (for an anion) for each atom using data from compounds having that specific...
    Resource Type:
    Dissertation
    Full Text:
    ) Shockley-Read-Hall recombination. . . . . . . . . . . . . . 13 2.8 Equivalent circuit model for a solar

  • Fabrication and characterization of thin-film transistor materials and devices

    Creator:
    Hong, David
    Abstract:
    A class of inorganic thin-film transistor (TFT) semiconductor materials has emerged involving oxides composed of post-transitional cations with (n-1)d¹⁰ns⁰ (n≥4) electronic configurations. This thesis is devoted to the pursuit of topics involving the development of these materials for TFT applications: Deposition of zinc oxide and zinc tin oxide semiconductor layers...
    Resource Type:
    Dissertation
    Full Text:
    defects, intentional donor doping (Al, In, Ga, B, F) or a combination thereof. Reported thin-film Hall

  • Inorganic thin-film solar cells

    Creator:
    Spies, Jack Alexander
    Abstract:
    The primary objective of this thesis is to explore new absorber and p-type window layer materials for thin-film solar cell applications. A new thin-film electron beam deposition system has been installed, is now operational, and has been used to deposit several types of solar cell absorber layers. Material investigations include...
    Resource Type:
    Masters Thesis
    Full Text:
    to explore new absorber and p-type window layer materials for thin-film solar cell applications. A

  • A study of deep levels of AlGaAs/GaAs heterojunction bipolar transistors

    Creator:
    Huang, Chun-ta
    Abstract:
    A study of deep levels of the emitter region of a heterojunction bipolar transistor is investigated using deep level transient spectroscopy (DLTS), deep level admittance spectroscopy (DLAS), thermally stimulated capacitance (TSCAP), and capacitance-voltage (C-V) profiling. The DX center, with an activation energy of 0.45 eV, is the only deep level...
    Resource Type:
    Masters Thesis
    Full Text:
    A study of deep levels of AlGaAs/GaAs heterojunction

  • Electrical characterization of n-type aluminum gallium arsenide

    Creator:
    Kim, Seung-bae
    Resource Type:
    Dissertation
    Full Text:
    extensive set of Hall measurements over a wide range of composition and hydrostatic pressure for Sn-doped

  • Instability and temperature-dependence assessment of IGZO TFTs

    Creator:
    Hoshino, Ken
    Abstract:
    Amorphous oxide semiconductors (AOSs) are of great current interest for thin-film transistor (TFT) channel layer applications. In particular, indium gallium zinc oxide (IGZO) is under intense development for commercial applications because of its demonstrated high performance at low processing temperatures. The objective of the research presented in this thesis is...
    Resource Type:
    Masters Thesis
    Full Text:
    ) – VGS transfer curves in which the turn-on voltage, VON, moves to a more positive gate voltage with

  • Thermally-stable amorphous metal thin films

    Creator:
    McGlone, John M.
    Abstract:
    Amorphous metal thin films (AMTFs) are of potential use for metal-insulator-metal (MIM) tunnel diode applications due to their ultra-smooth surfaces, a consequence of their amorphous microstructure. The objective of this thesis is to design a thermally-stable AMTF capable of maintaining MIM tunnel diode performance after a post-deposition anneal in excess...
    Resource Type:
    Masters Thesis
    Full Text:
    ultra-smooth surfaces, a consequence of their amorphous microstructure. The objective of this thesis is

  • Amorphous oxide semiconductors in circuit applications

    Creator:
    McFarlane, Brian Ross
    Abstract:
    The focus of this thesis is the investigation of thin-film transistors (TFTs) based on amorphous oxide semiconductors (AOSs) in two circuit applications. To date, circuits implemented with AOS-based TFTs have been primarily enhancement-enhancement inverters, ring oscillators based on these inverters operating at peak frequencies up to ~400 kHz, and two-transistor...
    Resource Type:
    Masters Thesis
    Full Text:
    active channel layer; a traditional full bridge rectifier with diode-tied transistors and a cross-tied

  • Fabrication process assessment and negative bias illumination stress study of IGZO and ZTO TFTs

    Creator:
    Hoshino, Ken
    Abstract:
    Indium-gallium-zinc oxide (IGZO) and zinc-tin oxide (ZTO) are investigated for thin-film transistor (TFT) applications. Negative bias illumination stress (NBIS) is employed for electrical stability assessment. Unpassivated IGZO and ZTO TFTs suffer from severe NBIS instabilities. Zinc-tin-silicon oxide is found to be an effective passivation layer for IGZO and ZTO TFTs,...
    Resource Type:
    Dissertation
    Full Text:
    vacancies. A ZTSO layer protects the channel layer top surface from adsorbed gas interactions and also

  • Transparent electronics : thin-film transistors and integrated circuits

    Creator:
    Presley, Rick E.
    Abstract:
    This thesis focuses on two aspects of transparent electronics, SnO₂ transparent thin-film transistors (TTFTs) and transparent circuits. Both depletion- and enhancement-mode SnO₂ TTFTs are realized. The maximum effective mobility for the depletion- and enhancement-mode devices are 2 cm²V⁻¹s⁻¹ and 0.8 cm²V⁻¹s⁻¹, respectively. A variety of techniques to decrease the carrier...
    Resource Type:
    Masters Thesis
    Full Text:
    and 0.8 cm2V−1s−1, respectively. A variety of techniques to decrease the carrier concentration in the

  • Development of Amorphous Metal Thin Films for Thermal Inkjet Printing and Microelectronics

    Creator:
    McGlone, John M.
    Abstract:
    Due to a lack of grain boundaries, an amorphous metal thin film (AMTF) possesses advantageous mechanical properties and enhanced chemical stability that is potentially useful for thermal inkjet (TIJ) printing applications. The use of an AMTF as a TIJ resistor or cavitation plate could lead to a thinner TIJ cavitation...
    Resource Type:
    Dissertation
    Full Text:
    . Abstract approved: John F. Wager Due to a lack of grain boundaries, an amorphous metal thin film (AMTF

  • Development of Cu-based Thin Films for Optoelectronic Applications

    Creator:
    Angelos, Gregory S.
    Abstract:
    CIGS and CdTe based commercial thin-film solar cells (TFSCs) require an absorber thickness greater than 2 µm and 4 µm, respectively, to adequately absorb the solar spectrum. To efficiently extract photoexcited electrons, these TFSCs require relatively defect-free absorbers with high-minority carrier mobility (> 100 cm2V−1s−1) and long lifetime (> 10...
    Resource Type:
    Dissertation
    Full Text:
    . Carriers separate as a result, giving rise to a Hall voltage, VH

  • Characterization of solution-based inorganic semiconductor and dielectric materials for inkjet printed electronics

    Creator:
    Munsee, Craig L.
    Abstract:
    The long-term goal of this research project is the development of solution-based inorganic dielectric and semiconductor materials for inkjet printed electronics. The main focus of this thesis involves testing of the materials and devices under development. A new solution-based inorganic dielectric material (HfOSO₄), given the name hafsox, is developed and...
    Resource Type:
    Masters Thesis
    Full Text:
    main focus of this thesis involves testing of the materials and devices under development. A new

  • Modeling and development of p-type thin-film transistors

    Creator:
    Spiegelberg, Matthew Craig
    Abstract:
    The primary focus of this thesis involves modeling and development of p-type thin-film transistors (p-TFTs), moving towards the realization of a filly transparent thin-film transistor (TTFT). The modeling portion of this thesis emphasizes the development of physics-based TFT models, specifically focusing on the elucidation of non-ideal current-voltage characteristic behavior. A...
    Resource Type:
    Masters Thesis
    Full Text:
    resistivity is 35 tnn-cm, with a Hall mobility of 3.5 cm2N-s, and a hole carrier concentration of 5 x 1019

  • DC/AC Stability of In-Ga-Zn-O Thin-Film Transistors

    Creator:
    Zhou, Fan
    Abstract:
    The electrical stability of amorphous indium-gallium-zinc oxide (a-IGZO) thinfilmtransistors (TFTs) is investigated for flat-panel display applications. Althoughproducts incorporating a-IGZO TFT backplanes are already commercially available,e.g., iMac with 5K retina display, technical challenges need to be addressed for nextgenerationapplications, e.g., active-matrix organic light-emitting diode displays.Device stability is one crucial issue. The...
    Resource Type:
    Dissertation
    Full Text:
    ), and high Hall mobility (µH > 10 cm2V-1s-1) [2]. The wide band gap of a-IGZO is due to the highly

  • Development of oxide semiconductors : materials, devices, and integration

    Creator:
    Chiang, Hai Q.
    Abstract:
    The aim of this dissertation is to develop oxide semiconductors by radio-frequency sputtering for thin-film transistor (TFT) applications. A variety of oxide semiconductors are used as the TFT channel layer, including indium gallium oxide (IGO), zinc tin oxide (ZTO), and indium gallium zinc oxide (IGZO). The variety of materials used...
    Resource Type:
    Dissertation
    Full Text:
    amorphous films exhibit a constant Hall mobility of∼ 10 cm2V−1s−1. The carrier concentration decreases

  • Development of zinc tin oxide-based transparent thin-film transistors

    Creator:
    Chiang, Hai Q.
    Abstract:
    The focus of this thesis involves development of highly transparent, n-channel, accumulation- mode thin-film transistors employing a zinc tin oxide (ZTO) channel layer. ZTO-based transparent thin-film transistors (TTFTs) show improved device performance compared to ZnO-based TTFTs. An estimated peak effective mobility for these devices as high as ~100 cm² V⁻¹sec⁻¹...
    Resource Type:
    Masters Thesis
    Full Text:
    measured Hall mobility for a RF magnetron sputter deposited thin-film is only 26 cm2V1sec'. Thin films

  • Instabilities in InP MIS capacitors

    Creator:
    Juang, Min Tzuan
    Abstract:
    The drain current of InP MISPETs is often observed to decrease as a function of time after the application of a positive gate bias which involves an accumulation of electrons in the channel. Various models have been proposed for this drain current drift (DCD) phenomenon. In this thesis, variable-temperature bias-stress...
    Resource Type:
    Masters Thesis
    Full Text:
    Warfield [14] who considered the application of Shockley- Read-Hall statistics to traps embedded in a

  • Low-cost deposition methods for transparent thin-film transistors

    Creator:
    Norris, Benjamin J.
    Abstract:
    The objective of this dissertation is to introduce low-cost processing methods for the fabrication of ZnO transparent thin-film transistors (TTFTs). A novel method for depositing ZnO body layers via spin-coating of a zinc nitrate-based spin solution is presented. The processing conditions of spin-coated ZnO are optimized to produce continuous and...
    Resource Type:
    Dissertation
    Full Text:
    fabrication of ZnO transparent thin-film transistors (TTFTs). A novel method for depositing ZnO body layers

  • Investigation of ultra-thin In-Ga-Zn-O thin-film transistors

    Creator:
    Chiang, Tsung-Han
    Abstract:
    The objective of the work reported herein is to explore the impact of decreasing channel thickness on radio-frequency (RF) sputtered amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) electrical performance through the evaluation of drain current versus gate voltage (I[subscript D] − V[subscript G]) transfer curves. For a fixed set of...
    Resource Type:
    Masters Thesis
    Full Text:
    radio-frequency (RF) sputtered amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs

  • p-type transparent electronics

    Creator:
    Valencia, Melinda Marie
    Abstract:
    The objective of this thesis is to contribute to the development of p-type materials for transparent electronics applications. Thin films of ®-BaCu2S2, a p-type semi-transparent semiconductor, are fabricated and characterized. ®-BaCu2S2 has a transmittance of 60% to 80 % in the visible portion of the electromagnetic spectrum. The mobility, conductivity,...
    Resource Type:
    Masters Thesis
    Full Text:
    applications. Thin films of α-BaCu2S2, a p-type semi-transparent semiconductor, are fabricated and

  • Development, fabrication, and characterization of transparent electronic devices

    Creator:
    Hoffman, Randy L.
    Abstract:
    The objective of this thesis is to provide an initial demonstration of the feasibility of constructing highly transparent active electronic devices. Such a demonstration is successfully achieved in the fabrication of ZnO-based thin film transistors (TFTs) exhibiting transparency greater than ~90% in the visible portion of the electromagnetic spectrum and...
    Resource Type:
    Masters Thesis
    Full Text:
    constructing highly transparent active electronic devices. Such a demon- stration is successfully achieved in

  • Contact resistance and stability assessment of oxide-based thin film transistors

    Creator:
    Hung, Celia M.
    Abstract:
    This thesis focuses on two aspects of oxide-based thin-film transistors (TFTs), contact resistance and instability assessment. First, determination of the contact resistance of indium tin oxide (ITO) on two wide-band gap semiconductors, zinc oxide (ZnO) and indium gallium oxide (IGO), is attempted and the effects of contact resistance on device...
    Resource Type:
    Masters Thesis
    Full Text:
    small. Second, a methodology for assessing the stability of oxide-based TFTs is developed and

  • Nontraditional amorphous oxide semiconductor thin-film transistor fabrication

    Creator:
    Sundholm, Eric Steven
    Abstract:
    Fabrication techniques and process integration considerations for amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) constitute the central theme of this dissertation. Within this theme three primary areas of focus are pursued. The first focus involves formulating a general framework for assessing passivation. Avoiding formation of an undesirable backside accumulation layer...
    Resource Type:
    Dissertation
    Full Text:
    a general framework for assessing passiva- tion. Avoiding formation of an undesirable backside

  • An n-sheet, state-space ACTFEL device model

    Creator:
    Hitt, John C.
    Abstract:
    The objective of the research presented in this thesis is to develop, implement, and demonstrate the utility of an n-sheet, state-space alternating-current thin-film electroluminescent (ACTFEL) device model. In this model, the phosphor layer is discretized into n + 1 layers, with band-to-band impact ionization, space charge creation/ annihilation, and luminescent...
    Resource Type:
    Dissertation
    Full Text:
    excitation/do-excitation occurring only at n sheets between the n + 1 layers. The state-space technique is a

  • Zinc tin oxide thin-film transistor current mirror circuits

    Creator:
    Feller, Layannah Elizabeth
    Abstract:
    The central focus of this thesis is the design, fabrication and characterization of amorphous oxide semiconductor (AOS) thin-film transistor (TFT) current mirrors. The thin-film deposition and circuit fabrication methods used to realize zinc tin oxide (ZTO) TFT current mirrors are addressed in order to elucidate the processing challenges for this...
    Resource Type:
    Masters Thesis
    Full Text:
    the use of AOS for a variety of appli- cations. Current mirrors are a vital analog circuit building

  • Novel ACTFEL phosphor development

    Creator:
    Ang, Wie Ming
    Abstract:
    The goal of this thesis is to identify and to explore novel ACTFEL phosphor materials. Several important materials properties relevant to ACTFEL phosphor development are identified. All of these properties cannot be obtained simultaneously. Therefore, several key phosphor materials properties are identified as critical to the development of an ACTFEL...
    Resource Type:
    Dissertation
    Full Text:
    phosphor. These includes the use of thick-film insulator, the use of a charge injection layer, the use of

  • Fabrication and characterization of ACTFEL devices

    Creator:
    Keir, Paul D.
    Abstract:
    The goal of this thesis is the identification and synthesis of high-luminance, primary color alternating-current thin-film electroluminescent (ACTFEL) devices. Special attention is paid to the synthesis of primary color green ACTFEL devices because of the lack of an adequate primary green ACTFEL phosphor and the dominance of green wavelengths in...
    Resource Type:
    Dissertation
    Full Text:
    spectrum with coactivators. Green ACTFEL devices exhibiting a high-luminance, high-efficiency, saturated

  • Numerical simulation of Al [subscript x] Ga [subscript 1-x] As/GaAs and (Al [subscript x] Ga [subscript 1-x]) [subscript 0.47] In [subscript 0.53] As/InP bandgap engineered solar cells

    Creator:
    Kamdar, Pravin P.
    Resource Type:
    Masters Thesis
    Full Text:
    the application of a numerical analysis program for the simulation of variable composition

  • Electronic Conduction Mechanisms in Insulators

    Creator:
    Chiang, Tsung-Han
    Abstract:
    The research presented herein focuses on electrical assessment of oxide thin films as insulators. The current density-electric field (J-E) characteristics of four insulators of dramatically different electrical quality are assessed in terms of their operative electronic conduction mechanisms. Conduction in the two high-quality insulators is dominated by Ohmic conduction and...
    Resource Type:
    Dissertation
    Full Text:
    of an Ohmic contact makes it difficult to ascertain how an Ohmic contact could be formed to a wide

  • State space modeling of alternating-current thin-film electroluminescent devices

    Creator:
    Peery, Jeffrey B.
    Resource Type:
    Masters Thesis
    Full Text:
    described herein is to perform a realistic simu- lation of the steady-state electrical characteristics of