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Title: Intersubband absorption in CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dot multilayers

Abstract

The authors report the observation of intersubband absorption in multilayers of CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dots. The samples were grown by molecular beam epitaxy on InP substrates. For samples with the CdSe dot layers doped with Cl and with the deposited CdSe equivalent layer thickness between 5.2 and 6.9 ML, peak absorption between 2.5 and 3.5 {mu}m was observed. These materials are promising for intersubband devices operating in the mid- and near-infrared ranges.

Authors:
; ; ; ; ; ; ; ; ; ;  [1];  [2];  [2];  [2];  [3]
  1. Department of Electrical Engineering, City College of the City University of New York, New York, New York 10031 (United States)
  2. (United States)
  3. (Canada)
Publication Date:
OSTI Identifier:
20971823
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 90; Journal Issue: 7; Other Information: DOI: 10.1063/1.2679783; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION; CADMIUM SELENIDES; CHLORINE; CRYSTAL GROWTH; DOPED MATERIALS; INDIUM PHOSPHIDES; INFRARED SPECTRA; LAYERS; MAGNESIUM COMPOUNDS; MOLECULAR BEAM EPITAXY; QUANTUM DOTS; SEMICONDUCTOR MATERIALS; SUBSTRATES; THICKNESS; ZINC COMPOUNDS

Citation Formats

Shen, A., Lu, H., Charles, W., Yokomizo, I., Tamargo, M. C., Franz, K. J., Gmachl, C., Zhang, S. K., Zhou, X., Alfano, R. R., Liu, H. C., Department of Chemistry, City College of the City University of New York, New York, New York 10031, Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, Institute for Ultrafast Spectroscopy and Lasers, Department of Physics, City College of the City University of New York, New York, New York 10031, and Institute for Microstructural Sciences, National Research Council, Ottawa, Ontario K1A 0R6. Intersubband absorption in CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dot multilayers. United States: N. p., 2007. Web. doi:10.1063/1.2679783.
Shen, A., Lu, H., Charles, W., Yokomizo, I., Tamargo, M. C., Franz, K. J., Gmachl, C., Zhang, S. K., Zhou, X., Alfano, R. R., Liu, H. C., Department of Chemistry, City College of the City University of New York, New York, New York 10031, Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, Institute for Ultrafast Spectroscopy and Lasers, Department of Physics, City College of the City University of New York, New York, New York 10031, & Institute for Microstructural Sciences, National Research Council, Ottawa, Ontario K1A 0R6. Intersubband absorption in CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dot multilayers. United States. doi:10.1063/1.2679783.
Shen, A., Lu, H., Charles, W., Yokomizo, I., Tamargo, M. C., Franz, K. J., Gmachl, C., Zhang, S. K., Zhou, X., Alfano, R. R., Liu, H. C., Department of Chemistry, City College of the City University of New York, New York, New York 10031, Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, Institute for Ultrafast Spectroscopy and Lasers, Department of Physics, City College of the City University of New York, New York, New York 10031, and Institute for Microstructural Sciences, National Research Council, Ottawa, Ontario K1A 0R6. Mon . "Intersubband absorption in CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dot multilayers". United States. doi:10.1063/1.2679783.
@article{osti_20971823,
title = {Intersubband absorption in CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dot multilayers},
author = {Shen, A. and Lu, H. and Charles, W. and Yokomizo, I. and Tamargo, M. C. and Franz, K. J. and Gmachl, C. and Zhang, S. K. and Zhou, X. and Alfano, R. R. and Liu, H. C. and Department of Chemistry, City College of the City University of New York, New York, New York 10031 and Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 and Institute for Ultrafast Spectroscopy and Lasers, Department of Physics, City College of the City University of New York, New York, New York 10031 and Institute for Microstructural Sciences, National Research Council, Ottawa, Ontario K1A 0R6},
abstractNote = {The authors report the observation of intersubband absorption in multilayers of CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dots. The samples were grown by molecular beam epitaxy on InP substrates. For samples with the CdSe dot layers doped with Cl and with the deposited CdSe equivalent layer thickness between 5.2 and 6.9 ML, peak absorption between 2.5 and 3.5 {mu}m was observed. These materials are promising for intersubband devices operating in the mid- and near-infrared ranges.},
doi = {10.1063/1.2679783},
journal = {Applied Physics Letters},
number = 7,
volume = 90,
place = {United States},
year = {Mon Feb 12 00:00:00 EST 2007},
month = {Mon Feb 12 00:00:00 EST 2007}
}
  • Multilayers of ZnS/ZnS{sub 1-x}Se{sub x} and ZnS/Zn{sub 1-x}Cd{sub x}S were successfully grown by molecular-beam epitaxy using elemental sources. Photoluminescence (PL) experiments were performed at 4.2 K to evaluate the optical quality and carrier-confinement properties of these multiple-quantum-well structures. In general, the emission peaks from the ZnS/Zn{sub 1-x}Cd{sub x}S samples were much sharper and more intense than those from ZnS films or ZnS/ZnS{sub 1-x}Se{sub x} multilayers. These PL characteristics indicate improved electron confinement in the Cd-based wells, implying that an appreciable conduction band offset exists between ZnS and Zn{sub 1-x}Cd{sub x}S. This work suggests that ZnS/Zn{sub 1-x}Cd{sub x}S quantum-well structures maymore » play an important role in the development of ultraviolet (UV) and near-UV light emitting structures. 9 refs., 3 figs.« less
  • We present a magneto-optical study of ZnSe/Zn{sub 1{minus}x{minus}y}Cd{sub x}Mn{sub y}Se quantum-well structures in which a suitable choice of the Cd composition leads to a system that is type I at zero magnetic field. When a magnetic field is applied perpendicular to the layers of the structure, the band edges split in such a way as to make the upper {bold {sigma}}{sub {minus}} (1/2, t 3/2) exciton transition type II, while the ground state {bold {sigma}}{sub +} ({minus}1/2, {minus}3/2) exciton component remains type I at all field values. This alignment reduces the probability for carrier relaxation from the higher-energy exciton componentmore » and opens the possibility of hole-spin population inversion via optical pumping. {copyright} {ital 1997} {ital The American Physical Society}« less
  • In this study, the properties of point defects in Cd 1–xZn xTe 1–ySe y (CZTS) radiation detectors are characterized using deep-level transient spectroscopy and compared between materials grown using two different methods, the Bridgman method and the traveling heater method. The nature of the traps was analyzed in terms of their capture cross-sections and trap concentrations, as well as their effects on the measured charge-carrier trapping and de-trapping times, and then compared for the two growth techniques. The results revealed that Se addition to CdZnTe can reduce the V Cd concentration. In Travelling Heater Method (THM) and Bridgman Methodmore » (BM) grown CZTS detectors, besides a few similarities in the shallow and medium energy traps, there were major differences in the deep traps. It was observed that the excess-Te and lower growth-temperature conditions in THM-grown CZTS led to a complete compensation of V Cd and two additional traps (attributed to Te i and Te Cd ++ appearing at around E v + 0.26 eV and E c – 0.78 eV, respectively). The 1.1-eV deep trap related to large Te secondary phases was a dominant trap in the BM-grown CZTS crystals. In addition to i-DLTS data, the effects of point defects induced due to different processing techniques on the detector's resistivity, spectral response to gammas, and μτ product were determined.« less
  • In this paper, the properties of point defects in Cd1-xZnxTe1-ySey (CZTS) radiation detectors are characterized using deep-level transient spectroscopy and compared between materials grown using two different methods, the Bridgman method and the traveling heater method. The nature of the traps was analyzed in terms of their capture cross-sections and trap concentrations, as well as their effects on the measured charge-carrier trapping and de-trapping times, and then compared for the two growth techniques. The results revealed that Se addition to CdZnTe can reduce the VCd- concentration. In Travelling Heater Method (THM) and Bridgman Method (BM) grown CZTS detectors, besides amore » few similarities in the shallow and medium energy traps, there were major differences in the deep traps. It was observed that the excess-Te and lower growth-temperature conditions in THM-grown CZTS led to a complete compensation of VCd- and two additional traps (attributed to Tei- and TeCd++ appearing at around Ev + 0.26 eV and Ec - 0.78 eV, respectively). The 1.1-eV deep trap related to large Te secondary phases was a dominant trap in the BM-grown CZTS crystals. In addition to i-DLTS data, the effects of point defects induced due to different processing techniques on the detector's resistivity, spectral response to gammas, and μτ product were determined.« less