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Proceedings Paper

Interfaces as design tools for short-period InAs/GaSb type-II superlattices for mid-infrared detectors
Author(s): F. Szmulowicz; H. J. Haugan; G. J. Brown; K. Mahalingam; B. Ullrich; S. R. Munshi; L. Grazulis
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Paper Abstract

The effect of interface anisotropy on the electronic structure of InAs/GaSb type-II superlattices is exploited in the design of thin-layer superlattices for mid-IR detection threshold. The design is based on a theoretical envelope function model that incorporates the change of anion and cation species across InAs/GaSb interfaces, in particular, across the preferred InSb interface. The model predicts that a given threshold can be reached for a range of superlattice periods with InAs and GaSb layers as thin as a few monolayers. The model also predicts that the absorbance for the 4 micron superlattices is inversely proportional to their period so that smaller period superlattices can be grown proportionately thinner. An added advantage of thin-period superlattices is a smaller hole mass and a lower Auger recombination rate, which should lead to higher detector operating temperatures. A number of superlattices with periods ranging from 50.6 to 21.2 Å for the 4 μm detection threshold were grown by molecular beam epitaxy based on the model design. Low temperature photoluminescence and photoresponse spectra confirmed that the superlattice band gaps remained constant at 330 meV although the period changed by the factor of 2.5. Overall, the present study points to the importance of interfaces as a tool in the design and growth of thin superlattices for mid-IR detectors for room temperature operation.

Paper Details

Date Published: 29 September 2005
PDF: 12 pages
Proc. SPIE 5957, Infrared Photoelectronics, 595708 (29 September 2005); doi: 10.1117/12.622219
Show Author Affiliations
F. Szmulowicz, Air Force Research Lab. (United States)
Univ. of Dayton Research Institute (United States)
H. J. Haugan, Air Force Research Lab. (United States)
Universal Technology Corp. (United States)
G. J. Brown, Air Force Research Lab. (United States)
K. Mahalingam, Air Force Research Lab. (United States)
Universal Technology Corp. (United States)
B. Ullrich, Bowling Green State Univ. (United States)
S. R. Munshi, Air Force Research Lab. (United States)
L. Grazulis, Air Force Research Lab. (United States)
Univ. of Dayton Research Institute (United States)

Published in SPIE Proceedings Vol. 5957:
Infrared Photoelectronics
Antoni Rogalski; Eustace L. Dereniak; Fiodor F. Sizov, Editor(s)

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