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Proceedings Paper

The role of InAs thickness on the material properties of InAs/GaSb superlattices
Author(s): H. J. Haugan; G. J. Brown; F. Szmulowicz; S. Elhamri; B. V. Olson; T. F. Boggess; L. Grazulis
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Paper Abstract

The epitaxial growth parameters optimized for mid-wavelength infrared (MWIR) InAs/GaSb superlattice (SL) growth are not directly applicable for long-wavelength infrared (LWIR) SL growth. We observed a two orders of magnitude drop in the spectral intensity of the measured photoresponse (PR) as the InAs layer thickness in the SL increases from 9 monolayers (MLs) to 16 MLs for a fixed GaSb layer thickness of 7 MLs. However, the theoretically calculated absorption strength decreases only by about a factor of two. So other factors affecting photoresponse, such as carrier mobility and lifetime, are likely responsible for the large drop in the PR of the LWIR SL in this sample set. In fact the measured Hall properties of MWIR and LWIR SLs are very different, with holes as the majority carriers in MWIR SLs and electrons as the majority carriers in LWIR SLs. Therefore we investigated the charge carrier density, carrier mobility, and carrier recombination dynamics in LWIR SL samples. Specifically we used temperature-dependent Hall effect and time-resolved pump-probe measurements to study the effect of adjusting several growth parameters on the background carrier concentrations and studied carrier lifetimes in LWIR SLs.

Paper Details

Date Published: 16 September 2011
PDF: 8 pages
Proc. SPIE 8154, Infrared Remote Sensing and Instrumentation XIX, 81540J (16 September 2011); doi: 10.1117/12.892751
Show Author Affiliations
H. J. Haugan, Air Force Research Lab. (United States)
G. J. Brown, Air Force Research Lab. (United States)
F. Szmulowicz, Air Force Research Lab. (United States)
S. Elhamri, Univ. of Dayton (United States)
B. V. Olson, The Univ. of Iowa (United States)
T. F. Boggess, The Univ. of Iowa (United States)
L. Grazulis, Air Force Research Lab. (United States)

Published in SPIE Proceedings Vol. 8154:
Infrared Remote Sensing and Instrumentation XIX
Marija Strojnik; Gonzalo Paez, Editor(s)

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