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Title: Modulation of intersubband absorption in tunnel-coupled quantum wells in electric fields

Abstract

Modulation of absorption of middle-infrared radiation in double tunneling-coupled quantum wells in longitudinal electric fields is studied. A specific feature of the quantum wells is the small separation in energy between the two lower levels. As a consequence, the levels may exhibit 'anticrossing' even in low transverse electric fields. An interpretation of the change in intersubband absorption is suggested. The interpretation is based on the assumption that a transverse electric-field component may appear in the structure. The change in the absorption coefficient is calculated taking into account the redistribution of electrons between size-quantization subbands and the changes in the temperature of electrons in the subbands in the longitudinal electric field, as well as the changes in the optical matrix elements, the energies of transitions, and the concentrations of electrons in the subbands in the transverse electric field. The possibility of using the structure for the efficient modulation of middle-infrared light with the photon energy 136 meV is shown.

Authors:
; ;  [1];  [2]
  1. St. Petersburg State Polytechnic University (Russian Federation)
  2. Carnegie Mellon University (United States)
Publication Date:
OSTI Identifier:
21088057
Resource Type:
Journal Article
Resource Relation:
Journal Name: Semiconductors; Journal Volume: 41; Journal Issue: 5; Other Information: DOI: 10.1134/S1063782607050211; 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; ABSORPTION; ELECTRIC FIELDS; ELECTRONS; INFRARED RADIATION; MEV RANGE 100-1000; PHOTONS; QUANTUM WELLS

Citation Formats

Zerova, V. L., E-mail: VZerova@rphf.spbstu.ru, Vorob'ev, L. E., Firsov, D. A., and Towe, E. Modulation of intersubband absorption in tunnel-coupled quantum wells in electric fields. United States: N. p., 2007. Web. doi:10.1134/S1063782607050211.
Zerova, V. L., E-mail: VZerova@rphf.spbstu.ru, Vorob'ev, L. E., Firsov, D. A., & Towe, E. Modulation of intersubband absorption in tunnel-coupled quantum wells in electric fields. United States. doi:10.1134/S1063782607050211.
Zerova, V. L., E-mail: VZerova@rphf.spbstu.ru, Vorob'ev, L. E., Firsov, D. A., and Towe, E. Tue . "Modulation of intersubband absorption in tunnel-coupled quantum wells in electric fields". United States. doi:10.1134/S1063782607050211.
@article{osti_21088057,
title = {Modulation of intersubband absorption in tunnel-coupled quantum wells in electric fields},
author = {Zerova, V. L., E-mail: VZerova@rphf.spbstu.ru and Vorob'ev, L. E. and Firsov, D. A. and Towe, E.},
abstractNote = {Modulation of absorption of middle-infrared radiation in double tunneling-coupled quantum wells in longitudinal electric fields is studied. A specific feature of the quantum wells is the small separation in energy between the two lower levels. As a consequence, the levels may exhibit 'anticrossing' even in low transverse electric fields. An interpretation of the change in intersubband absorption is suggested. The interpretation is based on the assumption that a transverse electric-field component may appear in the structure. The change in the absorption coefficient is calculated taking into account the redistribution of electrons between size-quantization subbands and the changes in the temperature of electrons in the subbands in the longitudinal electric field, as well as the changes in the optical matrix elements, the energies of transitions, and the concentrations of electrons in the subbands in the transverse electric field. The possibility of using the structure for the efficient modulation of middle-infrared light with the photon energy 136 meV is shown.},
doi = {10.1134/S1063782607050211},
journal = {Semiconductors},
number = 5,
volume = 41,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • The effect of a lateral electric field on the mid-infrared absorption and interband photoluminescence spectra in double tunnel-coupled GaAs/AlGaAs quantum wells is studied. The results obtained are explained by the redistribution of hot electrons between quantum wells and changes in the space charge in the structure. The hot carrier temperature is determined by analyzing the intersubband light absorption and interband photoluminescence modulation spectra under strong lateral electric fields.
  • The photoluminescence and intersubband absorption spectra are studied in GaAs/AlGaAs tunnel- coupled quantum well structures. The peak positions in the photoluminescence and absorption spectra are consistent with the theoretically calculated energies of optical carrier transitions. The effect of a transverse electric field and temperature on intersubband light absorption is studied. It is caused by electron redistribution between the size-quantization levels and a variation in the energy spectrum of quantum wells. The variation in the refractive index in the energy region of observed intersubband transitions is estimated using Kramers–Kronig relations.
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