Showing papers on "Heterojunction published in 1994"
TL;DR: Luminescent measurements show that the efficiency increases with decreasing size of the particles, as expected within the framework of an electron-hole localization theory, suggesting that doped nanocrystals are indeed a new class of materials heretofore unknown.
Abstract: We report for the first time that doped nanocrystals of semiconductor can yield both high luminescent efficiencies and lifetime shortening at the same time. Nanocrystals of Mn-doped ZnS with sizes varying from 3.5 to 7.5 nm were prepared by a room temperature chemical process. These nanosized particles have an external photoluminescent quantum efficiency as high as 18% at room temperature and a luminescent decay at least 5 orders of magnitude faster than the corresponding ${\mathrm{Mn}}^{2+}$ radiative transition in the bulk crystals. Luminescent measurements show that the efficiency increases with decreasing size of the particles, as expected within the framework of an electron-hole localization theory. These results suggest that doped nanocrystals are indeed a new class of materials heretofore unknown.
1,855 citations
TL;DR: In this paper, the combination of a layered perovskite compound (C6H5C2H4NH3)2PbI4 (PAPI), which forms a stable exciton with a large binding energy owing to its low-dimensional semiconductor nature and exhibits sharp and strong photoluminescence from the exciton band, and an electron-transporting oxadiazole derivative, was used to construct an organic-inorganic heterostructure electroluminescent (EL) device.
Abstract: Using the combination of a layered perovskite compound (C6H5C2H4NH3)2PbI4 (PAPI), which forms a stable exciton with a large binding energy owing to its low‐dimensional semiconductor nature and exhibits sharp and strong photoluminescence from the exciton band, and an electron‐transporting oxadiazole derivative, we fabricated an organic–inorganic heterostructure electroluminescent (EL) device. The EL spectrum of the device corresponded well to the photoluminescence spectrum of the PAPI film; the emission was peaking at 520 nm and half‐width of the emission was about 10 nm at liquid‐nitrogen temperature. Further, highly intense EL of more than 10 000 cd m−2 was performed at 2 A cm−2 at liquid‐nitrogen temperature in the device.
557 citations
Book•
01 Jan 1994
TL;DR: In this paper, the basic physical properties phase diagrams electrical properties band structure optical functions infra-red absorption and impurity energy levels photoluminescence and cathodoluminecence Raman and reflection spectra interfaces including heterojunctions.
Abstract: Basic physical properties phase diagrams electrical properties band structure optical functions infra-red absorption and impurity energy levels photoluminescence and cathodoluminescence Raman and reflection spectra interfaces including heterojunctions.
482 citations
26 Oct 1994
TL;DR: In this article, a brief review of the theoretical state of the art in the field of semiconductor interfaces is presented; it is shown that the important factor controlling the different semiconductor barrier heights is the density of states associated with the semiconductor dangling-bonds.
Abstract: A brief review of the theoretical state of the art in the field of semiconductor interfaces is presented. Itis shown that the important factor controlling the different semiconductor barrier heights is the densityof states associated with the semiconductor dangling-bonds. Passivated semiconductor surfaces presentsaturated dangling-bonds and have modified barrier heights. Results for hydrogen-passivated GaAs(11O)-surfaces are presented; it is shown that the Schottky-barrier height formed by the deposition of a K-layeris sustantially changed by the hydrogen-passivation. 1 INTRODUCTION Interfaces of crystalline materials are at the heart of different devices, and their understanding is basic toan appropriate design of many microelectronic systems. In this regard, semiconductors and their interfaceswith other semiconductors or metals have received the major attention1 , and we shall concentrate ourdiscussion in this paper on analyzing their basic electronic properties and their relation to the formationof different barriers.There are, basically, two kinds of semiconductor contacts: metal- semiconductor2'3 and semiconductor-semiconductor interfaces4. A great deal of the recent research in this field has been addressed to under-standing how their different barrier heights depend on the properties of the crystals forming the contact5.Fig.1 shows the main parameters defining each barrier: (a) for a metal semiconductor interface,
462 citations
TL;DR: In this article, the authors describe the self-organized formation of box-like microstructures during the interrupted epitaxial growth of strained InGaAs/AlGaAs multilayer structures on (311)B gallium arsenide substrates.
Abstract: LATERAL confinement of electrons or excitons in low-dimensional semiconductor structures (quantum ‘wires’ and ‘boxes’) leads to new electronic properties1, which can be used to improve the performance of optical devices such as semiconductor lasers and nonlinear optical switches2–4. Several state-of-the-art technologies have been applied to fabricate these quantum structures: lateral structure can be defined using high-resolution lithography combined with dry etching5,6, or by crystal growth on masked substrates7,8. Unfortunately, such processes inevitably result in a deterioration of the crystal quality. But recent reports9,10 of self-organized formation of quantum-wire semiconductor structures have attracted considerable interest as a means of overcoming these difficulties. We describe here the self-organized formation of box-like microstructures during the interrupted epitaxial growth of strained InGaAs/AlGaAs multilayer structures on (311)B gallium arsenide substrates. We find that the InGaAs layers organize spontaneously into homogeneous nanoscale disks embedded in an AlGaAs matrix. This phenomenon appears to arise from a complex interplay between the lattice strain, surface energy and surface migration.
275 citations
Patent•
27 May 1994TL;DR: In this article, a complimentary pair of compound semiconductor junction heterostructure field effect transistors and a method for their manufacture are disclosed, which has uses for the development of low power, high speed digital integrated circuits.
Abstract: A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits.
173 citations
TL;DR: In this article, the relationship between the photoluminescence (PL), light emitting device electroluminecence (EL), and conducting properties of a series of metalquinolates, Mq3, where M is a metal (Al, Ga, In, or Sc), and q3 is tris−(8−hydroxyquinoline).
Abstract: We present a systematic analysis of the relationship between the photoluminescence (PL), light emitting device electroluminescence (EL), and conducting properties of a series of metalquinolates, Mq3, where M is a metal (Al, Ga, In, or Sc), and q3 is tris‐(8‐hydroxyquinoline). We compare the solution and thin film PL quantum yields and spectra of each quinolate with the EL quantum efficiencies of organic heterojunction light emitting diodes using the compound as the emitter layer. Our results indicate that, contrary to previous reports, the relative PL yield is not a good indicator of the EL quantum efficiency of a particular material. Specifically, we find that while the PL of Alq3 films is four times that of Gaq3, light emitting devices made from these two materials have comparable electroluminescence quantum efficiencies and long‐term stabilities. Furthermore, the Gaq3 devices have an approximately 50% higher power efficiency than Alq3 structures, suggesting that Gaq3 is a superior emitter material for ...
163 citations
TL;DR: In this article, a model for the refractive index of InGaAsP and its dependence on the carrier density is presented, and the authors estimate a maximum tuning range of more than 15 nm for optimized Bragg reflection gratings.
Abstract: A model for the refractive index of InGaAsP and its dependence on the carrier density is presented. Full transport calculations for electrons and holes in heterostructures, including temperature effects, are used to show that the maximum injected carrier density is limited by electron heterojunction leakage for low-cladding doping and by recombination in the tuning layer for high-cladding doping. With the effective index method, we can then compute the maximum propagation constant change as a function of the waveguide geometry. Thermal effects are important only in the case of poor heatsinking. Using these results, we can estimate a maximum tuning range of more than 15 nm for optimized Bragg reflection gratings. >
158 citations
TL;DR: In this paper, the authors consider the operation of light-emitting diodes which use conjugated polymers for both charge transport and emission and highlight the improvement to the electroluminescence efficiency that can be produced by the use of two polymer layers selected so that the heterojunction between the two layers is able to confine charge and thus bring about efficient electron-hole capture to generate excitons.
149 citations
05 Dec 1994
TL;DR: In this article, a 1.0 cm/sup 2/CZ n-type single crystalline silicon (c-Si) solar cell with the "heterojunction with intrinsic thin-layer" (HIT) structure on both sides of the cell was presented.
Abstract: An aperture-area conversion efficiency of 20.0% (intrinsic efficiency: 21.0%) has been achieved for a 1.0 cm/sup 2/ CZ n-type single crystalline silicon (c-Si) solar cell, by using the "HIT (heterojunction with intrinsic thin-layer)" structure on both sides of the cell. This is the world's highest value for a c-Si solar cell in which the junction is fabricated at a low temperature of below 200/spl deg/C. In this paper, the junction fabrication technologies and features of the HIT structure are reviewed. The stability under light and thermal exposure, and the temperature dependence on performance of a high-efficiency HIT solar cell are also reported.
130 citations
TL;DR: An understanding of heteroepitaxy between perovskite and alkaline earth oxides is developed in terms of ion size and interfacial electrostatics, which presents the opportunity to study reduced dimensional or two-dimensional phenomena in thin-film ferroelectrics.
Abstract: An understanding of heteroepitaxy between perovskite and alkaline earth oxides is developed in terms of ion size and interfacial electrostatics. Interfacial energy minimization at the first atomic layers is the basis for a commensurate, unit-cell stability. This unit-cell stability presents the opportunity to study reduced dimensional or two-dimensional phenomena in thin-film ferroelectrics and is the basis for growth of high crystal quality, \ensuremath{\mu}m-thick films for optical device applications.
TL;DR: The results of comprehensive studies of photo-induced electron transfer from semiconducting (conjugated) polymers to buckminsterfullerene are reviewed in this article, where the importance of electron-phonon couplings is discussed.
Abstract: The results of comprehensive studies of photoinduced electron transfer from semiconducting (conjugated) polymers to buckminsterfullerene are reviewed. Steady state and femtosecond time-resolved photoinduced absorption (photoexcitation spectroscopy), steady state and picosecond time-resolved photoluminescence, steady state and picosecond photoconductivity, and steady state light-induced electron spin resonance measurements are summarized as experimental evidence which demonstrates ultrafast, long lived photoinduced electron transfer. Comparative studies with different semiconducting polymers as donors demonstrate that in degenerate ground state polymers, soliton excitations form before the electron transfer can occur; thereby inhibiting charge transfer and charge separation. In non-degenerate ground state systems, photoinduced electron transfer occurs in less than 10−12s, quenching the photoluminescence as well as the intersystem crossing into the triplet manifold. The importance of electron–phonon couplin...
Book•
01 Jan 1994
TL;DR: Structure of strained layers the kinetics of strained relaxation band structure and related properties optical properties Heterostructure Bipolar Transistors IR detectors FETS and other detectors.
Abstract: Structure of strained layers the kinetics of strained relaxation band structure and related properties optical properties Heterostructure Bipolar Transistors IR detectors FETS and other detectors.
TL;DR: In this article, a review of the luminescence and photoelectric properties of GaInAsSb/GaSb heterojunctions with staggered band alignment is presented, and the importance of tunnelling-assisted transitions through the interface in the radiative recombination of confined carriers is shown.
Abstract: This article reviews the pioneering investigations of the luminescence and photoelectric phenomena in type II heterojunctions based on the GaInAsSb/GaSb system. This system is remarkable because it is possible to create and study heterojunctions with both staggered and broken-gap alignment, depending on the alloy composition. Type II heterojunctions differ from type I in the existence of adjacent dual quantum wells for electrons and holes on both sides of the interface. Simultaneous confinement of electrons and holes in these wells causes unique optical and electrical properties of such heterojunctions and greatly modifies the characteristics of optoelectronic devices. The review considers the photo- and electroluminescence spectra of GaInAsSb/GaSb heterojunctions with staggered band alignment. The importance of tunnelling-assisted transitions through the interface in the radiative recombination of confined carriers is shown. The influence of these transitions on the structure and polarization characteristics of the luminescence spectra is considered. A new mechanism of photocurrent gain in isotype n-N heterojunctions due to hole confinement at the type II interface is discussed. Unusual asymmetric electrical properties of type II heterojunctions with broken-gap band alignment are demonstrated and discussed in connection with their energy band diagrams. Novel in light sources and photodetectors for the 1.6-4.7 mu m spectral range based on the GaInAsSb/GaSb system are briefly reviewed.
TL;DR: In this paper, the local Zn/Se relative concentration at the interface in ZnSe-GaAs(001) heterostructures synthesized by molecular beam epitaxy was found to be controlled by the flux ratio employed during the early growth stage of Zn-Se on GaAs.
Abstract: The local Zn/Se relative concentration at the interface in ZnSe-GaAs(001) heterostructures synthesized by molecular beam epitaxy was found to be controlled by the Zn/Se flux ratio employed during the early growth stage of ZnSe on GaAs. Correspondingly, the valence band discontinuity varies from 1.20 eV (Zn-rich interface) to 0.58 eV (Se-rich interface). Comparison with the results of first-principles calculations suggests that the observed trend in band offsets is related to the establishment of neutral interfaces with different atomic configurations.
TL;DR: The calculated energy dependence of the transition lifetimes is too strong to explain the observed low-energy slow emission band in porous Si purely in terms of transitions in an ideal wire, however, an alternative model, which introduces a mixture of wires and boxes, can account for the experimental slope.
Abstract: We have used the empirical pseudopotential method to study the electronic and optical properties of [001] Si quantum wires with (110)--([bar 1]10) square cross sections ranging from 4[times]4 to 14[times]14 monolayers (7.7[times]7.7 to 26.9[times]26.9 A, respectively). We present energy levels, band gaps, oscillator-strength, and charge-density distributions. To understand the electronic structure of these systems we calculate their properties in a stepwise process, considering (1) wires with a free surface but without hydrogen and (2) wires with hydrogen chemisorption on the surface. We find that (i) in both cases, the band gap between bulklike states increases as the wire size is reduced (due to quantum confinement). However, (ii) hydrogen chemisorption acts to reduce the gap. (iii) Whereas the low-energy states near the valence-band [ital minimum] are effective-mass-like, the near-band-gap states with or without H on the surface can be decisively non-effective-mass-like. The lowest conduction states are pseudodirect, not direct. (iv) The calculated energy dependence of the transition lifetimes is too strong to explain the observed low-energy slow'' emission band in porous Si purely in terms of transitions in an ideal wire. However, an alternative model, which introduces a mixture of wires and boxes, can account for the experimental slope.
Book•
01 Jan 1994
TL;DR: In this paper, a Monte Carlo simulation physics and models related to p/n junctions are presented. But the authors do not consider the effect of nonuniform doping concentration in bipolar transistors.
Abstract: Semiconductor device fundamentals - energy band theory, statistics of free carriers in semiconductors, generation and recombination processes, Boltzmann transport equation, drift and diffusion mechanisms, carrier scattering mechanisms, basic semiconductor device equations, Monte Carlo simulation physics and models related to p/n junctions - description of p/n junctions, ambipolar transport equation, Linvill lumped circuit model, Sah transmission line circuit model, current and avalanche breakdown in reverse-biased junctions, tunnelling currents in p/n junctions, charge storage in p/n junctions, abrupt heterojunction diodes, abrupt heterojunctions with a setback layer, graded heterojunctions, references, problems bipolar junction transistors - steady-state characteristics under forward-active operation, current-voltage characteristics including saturation and current-induced base pushout, effect of quasineutral base width modulation, effect of nonuniform doping concentration, avalanche multiplication in bipolar transistor, multidimensional effects, poly-emitter bipolar transistors, switching speed of BJTs, large- and small-signal models, references, problems junction field-effect transistors - general theory, current-voltage characteristics of three-terminal JFETs, current-voltage characteristics of four-terminal JFETs, short-channel JFETs, large-and small-signal models, references, problems metal-oxide-semiconductor field-effect devices - metal-oxide-semiconductor (MOS) diodes, metal-oxide semiconductor field-effect transistors (MOSFET), numerical and experimental results, hot-carrier effects, capacitance of intrinsic MOSFET, MOSFET equivalent circuit, references, problems metal-semiconductor junction devices - Schottky diodes, ohmic contacts, metal-semiconductor field-effect transistors (MESFET), references, problems heterojunction bipolar and field-effect transistors - single heterojunction bipolar transistors, abrupt HBTs with a setback layer, HBTs with a graded uunction, double heterojunction bipolar transistors, heterojunction field-effect transistors, references, problems solar cells - basic concept, homojunction solar cells, heterojunction in solar cells, effect of V-groove surface on solar cell performance, references, problems photoconductive diodes - device structure and concept, general theories, conductivity and current, effect of contact regions, two-dimensional analysis, transient behaviour of photoconductive diodes, references, problems.
TL;DR: In this paper, the interface states formed by exposure to air are suggested to play important roles in chemical sensing, and the type II junction shows little sensitivity to humidity and flammable gas (CO and H 2 ) compared to the type I junction.
Abstract: Humidity- and gas (CO, H 2 )-sensing properties of CuO/ZnO thin-film junctions fabricated by different procedures have been investigated. Junctions in which the lower layer surface is exposed to air before stacking the upper layer (type I) and junctions deposted continuously (type II) have been prepared by the sputtering method. The type II junction shows little sensitivity to humidity and flammable gas (CO and H 2 ) compared to the type I junction. The interface capacitance in type I is almost independent of the applied bias. This indicates that the interface state are dominant for determining the electrical properties of the junction. The interface states formed by exposure to air are suggested to play important roles in chemical sensing.
TL;DR: By ultraclean low-pressure chemical vapor deposition (CVD) using SiH4 and GeH4 gases, low-temperature epitaxial growth of Si/Si1-x Gex /Si heterostructures at high Ge fractions on Si(100) is achieved.
Abstract: By ultraclean low-pressure chemical vapor deposition (CVD) using SiH4 and GeH4 gases, low-temperature epitaxial growth of Si/Si1-x Gex /Si heterostructures at high Ge fractions on Si(100) is achieved The deposition rate and Ge fraction are controlled by the SiH4 and GeH4 partial pressures and the deposition temperature Atomically flat surfaces and interfaces for the heterostructures containing Si08Ge02, Si05Ge05 and Si03Ge07 layers are obtained by deposition at 550, 500 and 450° C, respectively Cross-sectional transmission electron microscope (TEM) images and Raman spectra show that these samples have excellent epitaxial qualities It is also found that the Si05Ge05-channel metal-oxide-semiconductor field-effect transistor (MOSFET) has the highest peak field-effect mobility Moreover, the atomic-layer growth of Si and Ge is achieved by the separation of surface adsorption and reaction of reactant gases The adsorption processes of SiH4 and GeH4 are found to be described by the Langmuir adsorption-type equation
TL;DR: In this article, high-speed InAs/AlSb-based heterostructure field effect transistors (HFETs) displaying greatly improved charge control properties and enhanced high-frequency gate performance.
Abstract: We demonstrate high-speed InAs/AlSb-based heterostructure field-effect transistors (HFET's) displaying greatly improved charge control properties and enhanced high-frequency gate performance. Microwave devices with a 0.5/spl times/84 /spl mu/m/sup 2/ exhibit a peak unity current gain cut-off frequency of f/sub T/=93 GHz. The HFET usable operational range was extended to V/sub DS/=1.5 V (from V/sub DS/=0.4-0.5 V) thus greatly enhancing the applicability of InAs/AlSb-based HFET's for low-power, high-frequency amplification. We also report on the bias dependence of f/sub T/, and demonstrate that InAs/AlSb-based HFET's offer an attractive frequency performance over an adequately wide range of drain biases. >
TL;DR: In this paper, a Pd/ZnO/p-Si heterojuncion was used for room-temperature hydrogen sensing in pure air and in air with different concentrations (2000−20 000 ppm) of hydrogen.
Abstract: Device-quality ZnO thin film is deposited by using an indigenously developed modified CVD method and a Pd/ZnO/p-Si heterojuncion is fabricated. A study of the current-voltage characteristics of the heterojunction in pure air and in air with different concentrations (2000−20 000 ppm) of hydrogen reveals that the device can be used as a room-temperature hydrogen sensor down to a level of hydrogen below its explosion mixture with air. The saturation sensitivity and time response of the device with respect to the different hydrogen concentrations in air has been studied. The device operating at 1 V forward bias shows a maximum saturation sensitivity in different hydrogen concentrations. At 20 000 ppm. H2 in air, the sensitivity is found to be 5×102, while the time response is 162 s. The increase of surface conductivity of ZnO at the Pd/ZnO interface due to the adsorption and chemical interaction of hydrogen is found to play a key role in sensing. This mechanism of hydrogen sensing is verified by a double-metal-gate heterojunction.
TL;DR: In this paper, high tetrahedral amorphous carbon (ta-C) films and its hydrogenated form (Ta-C:H) have been deposited using a filtered cathodic arc.
Abstract: Highly tetrahedral amorphous carbon (ta-C) films and its hydrogenated form (ta-C:H) have been deposited using a filtered cathodic arc. In this paper, the optical and electronic band-gaps of amorphous diamond and its hydrogenated form ta-C:H, are shown to be in the range 2 eV. The H content of ta-C:H is found to be about 3 at.% using elastic recoil detection analysis (ERDA) and electron energy loss spectroscopy (EELS) is used to show that ta-C:H does keep its tetrahedral structure. Both materials are found to be stable at temperatures up to 1000 K. The room temperature conductivity of 10−7−10−8 Ω−1cm−1 is shown to be thermally activated, with activation energies in the range 0.2–0.3 eV. A detailed study made from the current-voltage characteristics of ta-C/p-Si heterojunctions shows that current flow is space-charge limited (SCLC) and influenced by bulk traps. The density of states profile, N(fE), in the region of the quasi-Fermi level is calculated using the differential method and found to be of the order 1018 cm−13 eV−1. Optical absorption data is coupled with the electrical results to confirm that the valence band density of states is of the order 1021 cm−13 eV−1. It is also shown that there is a reduction of nearly one order of magnitude in the N(E) at the quasi-Fermi level upon hydrogenation. SCLC measurements are complemented with surface admittance measurements (SAM) which yield a value of 1011 cm−2 eV−1 for the interfacial density of states at the ta-C/p-Si junction. A decrease in Nss is also observed at the ta-C:H/p-Si interface in agreement with the SCLC results.
TL;DR: In this article, a double-heterostructure diode laser emitting at 3 μm has exhibited pulsed operation at temperatures up to 255 K and cw operation up to 170 K, with cw output power of 45 mW/facet at 100 K.
Abstract: Double‐heterostructure diode lasers emitting at 3 μm have exhibited pulsed operation at temperatures up to 255 K and cw operation up to 170 K, with cw output power of 45 mW/facet at 100 K. The laser structure, grown on GaSb substrates by molecular beam epitaxy, has a metastable GaInAsSb active layer and AlGaAsSb cladding layers. The lowest pulsed threshold current density is 9 A/cm2 obtained at 40 K. The characteristic temperature is 35 K at low temperatures and 28 K above 120 K.
TL;DR: In this paper, an oxide-nitride-oxide (ONO) heterostructure was used as a dielectric material in a metal-insulator-semiconductor field effect transistor with Si as a semiconductor.
Abstract: In this letter, we report our study on an oxide‐nitride‐oxide (ONO) heterostructure as a dielectric material in a metal‐insulator‐semiconductor field‐effect transistor with Si as a semiconductor. The electrical properties of the ONO dielectrics have been correlated with: (i) the process related effects; (ii) the accumulation of N atoms and its bonding with Si at the SiO2/Si interface; and (iii) the chemical bonding within the nitride layers. By combining the remote plasma enhanced chemical vapor deposition and the rapid thermal annealing process, the device quality ONO structure with an oxide equivalent thickness of 4.7 nm has been successfully manufactured.
TL;DR: In this paper, the formation of the heterojunction interface between polycrystalline ZnO and CdS has been studied with x-ray and ultraviolet photoemission spectroscopy.
Abstract: The highest conversion efficiencies of solar cells based on Cu(In,Ga)Se2 have been achieved using multilayer CdS/ZnO front contacts. The formation of the heterojunction interface between polycrystalline ZnO and CdS has been studied with x‐ray and ultraviolet photoemission spectroscopy. The valence band offset between ZnO and CdS has been determined to be 1.2 eV. No chemical reactions at the interface between ZnO and CdS have been detected up to 200 °C. In order to obtain a standard reference for the band discontinuities the valence band offsets of ZnO and CdS relative to Ge have been measured.
Book•
06 Dec 1994
TL;DR: In this paper, the LCAO method was used to calculate the true band structure of column IV elements calculated by the k * p method, which is a measure of the potential of a pure semiconductor to contain impurities.
Abstract: 1 Simple Ideas about Semiconductors- 11 Definition and Importance of Semiconductors- 12 A Chemical Approach to Semiconductors- 13 Quantum States of a Perfect One-Dimensional Crystalline Solid- 2 Quantum States of a Perfect Semiconductor- 21 Quantum States of a Three-Dimensional Crystal- 22 Dynamics of a Bloch Electron The Crystal Momentum- 23 Metal, Insulator, Semiconductor- 24 Theoretical Determination of Band Structure- 25 The True Band Structure- 26 Experimental Study of Band Structure- Appendix 21 Matrix Element of a Periodic Operator between Two Bloch States- Appendix 22 Symmetries of the Band Structure- Appendix 23 Band Structure of Column IV Elements Calculated by the LCAO Method- Appendix 24 The k * p Method- 3 Excited States of a Pure Semiconductor and Quantum States of Impure Semiconductors- 31 The Hole Concept- 32 Impurities in Semiconductors- 33 Impurity Bands- Appendix 31 Problems on Cyclotron Resonance in Silicon- Appendix 32 Quantum Wells and Semiconducting Superlattices- Appendix 33 Amorphous Semiconductors- 4 Statistics of Homogeneous Semiconductors- 41 Occupation of the Electron Levels- 42 Hole Occupation- 43 Determination of the Chemical Potential- 44 Statistics of Pure or Intrinsic Semiconductors- 45 Statistics of a Semiconductor Containing Impurities: The Notion of Majority and Minority Carriers- 46 Compensated Semiconductor at Intermediate Temperature- 47 Semiconductor at Low Temperatures- 48 Application: The Semiconducting Thermometer- 49 Growth of Pure Crystals- Appendix 41 Occupation Number of a Donor Level- Appendix 42 Problem: Substrates for Microelectronics- 5 Transport Phenomena in Semiconductors- 51 Introduction- 52 Drude's Model of Conductivity and Diffusion- 53 Semiclassical Treatment of Transport Processes- 54 The Mobility of Semiconductors- Appendix 51 Problems on the Hall Effect and Magnetoresistance of Semiconductors in the Drude Model- 6 Effects of Light- 61 Light Absorption by Semiconductors- 62 Recombination- 63 Photoconductivity and its Applications- Appendix 61 Quantum System Submitted to a Sinusoidally Varying Perturbation- Appendix 62 Calculation of the Radiative Recombination Probability- Appendix 63 Semiconducting Clusters for Non-Linear Optics- 7 Carrier Injection by Light- 71 Basic Equations for Semiconductor Devices- 72 Charge Neutrality- 73 Injection or Extraction of Minority Carriers- Appendix 71 Charge Quasi-Neutrality- Appendix 72 Problems on Photoexcitation, Recombination, and Photoconductivity- 8 The p-n Junction- 81 Introduction: Inhomogeneous Semiconductors- 82 The Equilibrium p-n Junction- 83 The Non-Equilibrium Junction- Appendix 81 Problem: Non-Stationary p-n Junctions and their High-Frequency Applications- 9 Applications of the p-n Junction and Asymmetrical Devices- 91 Applications of p-n Junctions- 92 The Metal-Semiconductor Contact in Equilibrium- 93 Non-Equilibrium Metal-Semiconductor Junction- 94 The Semiconductor Surface- 95 Photoemission from Semiconductors- 96 Heterojunctions- 10 The Principles of Some Electronic Devices- 101 The Junction Transistor- 102 The Field-Effect Transistor- 103 An Application of the MOSFET: The Charge-Coupled Device (CCD)- 104 Concepts of Integration and Planar Technology- 105 Band Gap Engineering- 106 Physical Limits in Digital Electronics- Appendix 101 Problems on the n-p-n Transistor- Appendix 102 Problems on the Junction Field-Effect Transistor- Appendix 103 Problems on MOS (Metal-Oxide-Semiconductor) Structure- Values of the Important Physical Constants- Some Physical Properties of Semiconductors
TL;DR: In this article, the strain-induced lateral layer ordering (SILO) process was used to produce GaInP/AlGaInP strained multiple quantum wire (MQWR) heterostructure lasers.
Abstract: We have established an in situ technique, the strain-induced lateral-layer ordering (SILO) process, whereby lateral composition modulation perpendicular to the growth direction occurs spontaneously during growth by gas source molecular beam epitaxy, producing lateral quantum wells. We have combined this new growth technique with standard quantum well laser growth technology to produce GaInP/AlGaInP strained multiple quantum wire (MQWR) heterostructure lasers. Transmission electron microscopy confirms the presence of laterally ordered MQWR arrays with a linear density of 10/sup 6/ cm/sup -1/. Emission spectra from these MBWR heterostructures exhibit quantized energies and significant polarization anisotropies. Photoluminescence emission energies are analyzed using an approximate strained quantum wire calculation. Electroluminescence spectra are studied both above and below the lasing threshold. Threshold current densities as low as 250 A/cm/sup 2/ are obtained under pulsed conditions at 77 K. The energies, polarizations, and threshold current densities vary according to the orientation of the contact stripe with respect to the MBWR array. These effects are explained in terms of the quantum wire potential, the strain fields present in the MQWR active region, and their effects on the band structure and the optical gain. >
TL;DR: In this paper, the authors describe a compact growth system specifically designed for metalorganic molecular-beam epitaxy (MOMBE) of InP-based materials using a fixed sample heating stage which is designed for indium wafer mounting, up to a 2 in. diameter.
Abstract: This article describes a compact growth system specifically designed for metalorganic molecular‐beam epitaxy (MOMBE) of InP‐based materials. The system is designed to take full advantage of the MOMBE method, in particular the premixing of the group III and V precursors, respectively, and the elimination of large solid effusion cells. The system uses a fixed sample heating stage which is designed for indium wafer mounting, up to a 2 in. diameter, on molybdenum blocks. Temperature control during growth is done with a thermocouple inserted directly into the sample block with a small charge of indium to provide intimate thermal contact. Sample loading is done vertically from above in order to load the sample in the growth position. The system is controlled by a personal computer, which also replaces all of the analog temperature and pressure controllers. Initial results on 2‐in. diameter wafers indicate excellent uniformity of the composition, Δa/a=±2×10−4 for InGaAs, and photoluminescence, ±4.5 nm for InGaAsP, respectively. In addition, high‐speed InGaAs/InP heterostructure bipolar transistors and charge injection transistors grown in this system have demonstrated fT’s of 125 and 73 GHz, respectively.
01 Feb 1994-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this article, high dose implantation of Fe + ions into (111)Si substrates and subsequent two-step annealing was fabricated epitaxial Si/s-FeSi 2 /Si heterostructures.
Abstract: By high dose implantation of Fe + ions into (111)Si substrates and subsequent two-step annealing we fabricated epitaxial Si/s-FeSi 2 /Si heterostructures. Photoluminescence measurements reveal a band at about 1.55 μm which is attributed to be due to defects in the Si matrix. Photothermal deflection spectroscopy at room temperature revealed a direct transition at ≈ 0.83 eV, but in addition experimental evidence was found for an indirect transition with an energy of ≈ 0.78 eV. Measurements of the Hall coefficient as a function of temperature indicated hole concentrations of 9 × 10 18 cm −3 and remarkably high mobilities of about 104 cm 2 /Vs in buried β-FeSi 2 layers at room temperature. By implanting Mn (concentration ≈ 1%) it was possible to fabricate semiconducting Mn 0.03 Fe 0.97 Si 2 which showed an increased hole concentration of 1.6 × 10 19 cm −3 and mobilities of ≈ 90 cm 2 /Vs.