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Title: Characterization of In{sub x}Ga{sub 1-x}As/GaAs quantum-well heterostructures by C-V measurements: Band offsets, quantum-confinement levels, and wave functions

Abstract

The method of C-V profiling combined with self-consistent solution of Schroedinger's and Poisson's equations was used to determine with high precision the absolute values of the conduction-band offsets, energies of quantum-confinement levels, and charge-carrier concentrations in quantum-confinement subbands of In{sub x}Ga{sub 1-x}As/GaAs quantum-well heterostructures with In content corresponding to the pseudomorphic growth mode (0 < x < 0.3). A characterization technique based on capacitance measurements is developed, enabling one to determine the main electronic parameters of quantum-confinement heterostructures.

Authors:
 [1]
  1. St. Petersburg State Electrotechnical University (LETI) (Russian Federation), E-mail: VIZubkov@mail.eltech.ru
Publication Date:
OSTI Identifier:
21088100
Resource Type:
Journal Article
Resource Relation:
Journal Name: Semiconductors; Journal Volume: 41; Journal Issue: 3; Other Information: DOI: 10.1134/S1063782607030153; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Ltd; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CHARGE CARRIERS; GALLIUM ARSENIDES; INDIUM COMPOUNDS; POISSON EQUATION; QUANTUM WELLS; WAVE FUNCTIONS

Citation Formats

Zubkov, V. I. Characterization of In{sub x}Ga{sub 1-x}As/GaAs quantum-well heterostructures by C-V measurements: Band offsets, quantum-confinement levels, and wave functions. United States: N. p., 2007. Web. doi:10.1134/S1063782607030153.
Zubkov, V. I. Characterization of In{sub x}Ga{sub 1-x}As/GaAs quantum-well heterostructures by C-V measurements: Band offsets, quantum-confinement levels, and wave functions. United States. doi:10.1134/S1063782607030153.
Zubkov, V. I. Thu . "Characterization of In{sub x}Ga{sub 1-x}As/GaAs quantum-well heterostructures by C-V measurements: Band offsets, quantum-confinement levels, and wave functions". United States. doi:10.1134/S1063782607030153.
@article{osti_21088100,
title = {Characterization of In{sub x}Ga{sub 1-x}As/GaAs quantum-well heterostructures by C-V measurements: Band offsets, quantum-confinement levels, and wave functions},
author = {Zubkov, V. I.},
abstractNote = {The method of C-V profiling combined with self-consistent solution of Schroedinger's and Poisson's equations was used to determine with high precision the absolute values of the conduction-band offsets, energies of quantum-confinement levels, and charge-carrier concentrations in quantum-confinement subbands of In{sub x}Ga{sub 1-x}As/GaAs quantum-well heterostructures with In content corresponding to the pseudomorphic growth mode (0 < x < 0.3). A characterization technique based on capacitance measurements is developed, enabling one to determine the main electronic parameters of quantum-confinement heterostructures.},
doi = {10.1134/S1063782607030153},
journal = {Semiconductors},
number = 3,
volume = 41,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
  • We report an extensive investigation of semiconductor band-structure effects in single-barrier Al{sub x}Ga{sub 1{minus}x}As/GaAs heterostructures using ballistic-electron-emission spectroscopy (BEES). The transport mechanisms in these single-barrier structures were studied systematically as a function of temperature and Al composition over the full compositional range (0{le}x{le}1). The initial ({Gamma}) BEES thresholds for Al{sub x}Ga{sub 1{minus}x}As single barriers with 0{le}x{le}0.42 were extracted using a model which includes the complete transmission probability of the metal-semiconductor interface and the semiconductor heterostructure. Band offsets measured by BEES are in good agreement with previous measurements by other techniques which demonstrates the accuracy of this technique. BEES measurements atmore » 77 K give the same band-offset values as at room temperature. When a reverse bias is applied to the heterostructures, the BEES thresholds shift to lower voltages in good agreement with the expected bias-induced band-bending. In the indirect band-gap regime ({ital x}{gt}0.45), spectra show a weak ballistic-electron-emission microscopy current contribution due to intervalley scattering through Al{sub x}Ga{sub 1{minus}x}As {ital X} valley states. Low-temperature spectra show a marked reduction in this intervalley current component, indicating that intervalley phonon scattering at the GaAs/Al{sub x}Ga{sub 1{minus}x}As interface produces a significant fraction of this{ital X} valley current. A comparison of the BEES thresholds with the expected composition dependence of the Al{sub x}Ga{sub 1{minus}x}As {Gamma}, {ital L}, and {ital X} points yields good agreement over the entire composition range. {copyright} {ital 1997} {ital The American Physical Society}« less
  • Gd{sub 2}O{sub 3} films were prepared on (0001)-oriented Al{sub x}Ga{sub 1−x}N (0 ≤ x ≤ 0.67) thin film substrates via reactive molecular-beam epitaxy. X-ray diffraction revealed that these films possessed the cubic bixbyite structure regardless of substrate composition and were all 111-oriented with in-plane rotations to account for the symmetry difference between the oxide film and nitride epilayer. Valence band offsets were characterized by X-ray photoelectron spectroscopy and were determined to be 0.41 ± 0.02 eV, 0.17 ± 0.02 eV, and 0.06 ± 0.03 eV at the Gd{sub 2}O{sub 3}/Al{sub x}Ga{sub 1−x}N interfaces for x = 0, 0.28, and 0.67, respectively.
  • Photoluminescence (77 and 300 K) and transmission electron microscopy (TEM) data are presented on Al/sub x/Ga/sub 1-//sub x/As-GaAs quantum well heterostructures with Se sheet doping in the GaAs quantum wells and Mg sheet doping in the Al/sub x/Ga/sub 1-//sub x/As (x--0.2) barriers. Sheet or ''spike'' doping, which is surface deposited during the metalorganic chemical vapor deposition crystal growth, leads to a high impurity concentration and direct observation of the doping layer in TEM. Photopumped laser operation (77 and 300 K, pulsed and continuous) of compensated samples leads to modes 30--40 meV below the n = 1 confined-particle electron-to-heavy-hole transition andmore » involves the Se impurity. Mg spike doping of the barriers is used to compensate the Se doping of the wells, making the active region p type and thus allowing the observation of stimulated emission involving the ''spike'' distribution of Se.« less
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