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Title: Spatially indirect radiative recombination in InAlAsSb grown lattice-matched to InP by molecular beam epitaxy

A photoluminescence (PL) spectroscopy study of the bulk quaternary alloy InAlAsSb is presented. Samples were grown lattice-matched to InP by molecular beam epitaxy and two different growth temperatures of 450 °C and 325 °C were compared. Interpolated bandgap energies suggest that the development of this alloy would extend the range of available direct bandgaps attainable in materials lattice-matched to InP to energies as high as 1.81 eV. However, the peak energy of the observed PL emission is anomalously low for samples grown at both temperatures, with the 450 °C sample showing larger deviation from the expected bandgap. A fit of the integrated PL intensity (I) to an I∝P{sup k} dependence, where P is the incident power density, yields characteristic coefficients k = 1.05 and 1.18 for the 450 °C and 325 °C samples, respectively. This indicates that the PL from both samples is dominated by excitonic recombination. A blue-shift in the peak emission energy as a function of P, along with an S-shaped temperature dependence, is observed. These trends are characteristic of spatially-indirect recombination associated with compositional variations. The energy depth of the confining potential, as derived from the thermal quenching of the photoluminescence, is 0.14 eV for the 325 °C sample, which is consistent with the red-shift of themore » PL emission peak relative to the expected bandgap energy. This suggests that compositional variation is the primary cause of the anomalously low PL emission peak energy. The higher energy PL emission of the 325 °C sample, relative to the 450 °C sample, is consistent with a reduction of the compositional fluctuations. The lower growth temperature is therefore considered more favorable for further growth optimization.« less
Authors:
; ; ; ; ; ;  [1] ;  [2] ;  [3]
  1. U.S. Naval Research Laboratory, 4555 Overlook Ave. SW., Washington, DC 20375 (United States)
  2. The George Washington University, 2121 I Street NW, Washington, DC 20037 (United States)
  3. Sotera Defense Solutions, Inc., Annapolis Junction, Maryland 20701-1067 (United States)
Publication Date:
OSTI Identifier:
22412902
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM ARSENIDES; COMPARATIVE EVALUATIONS; EMISSION SPECTROSCOPY; ENERGY GAP; FLUCTUATIONS; INDIUM ANTIMONIDES; INDIUM PHOSPHIDES; MOLECULAR BEAM EPITAXY; PHOTOLUMINESCENCE; POTENTIALS; QUATERNARY ALLOY SYSTEMS; RECOMBINATION; RED SHIFT; TEMPERATURE DEPENDENCE