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Title: Electrical properties of n-type GaSb substrates and p-type GaSb buffer layers for InAs/InGaSb superlattice infrared detectors

Lightly doped n-type GaSb substrates with p-type GaSb buffer layers are the preferred templates for growth of InAs/InGaSb superlattices used in infrared detector applications because of relatively high infrared transmission and a close lattice match to the superlattices. We report here temperature dependent resistivity and Hall effect measurements of bare substrates and substrate-p-type buffer layer structures grown by molecular beam epitaxy. Multicarrier analysis of the resistivity and Hall coefficient data demonstrate that high temperature transport in the substrates is due to conduction in both the high mobility zone center Γ band and the low mobility off-center L band. High overall mobility values indicate the absence of close compensation and that improved infrared and transport properties were achieved by a reduction in intrinsic acceptor concentration. Standard transport measurements of the undoped buffer layers show p-type conduction up to 300 K indicating electrical isolation of the buffer layer from the lightly n-type GaSb substrate. However, the highest temperature data indicate the early stages of the expected p to n type conversion which leads to apparent anomalously high carrier concentrations and lower than expected mobilities. Data at 77 K indicate very high quality buffer layers.
Authors:
; ; ;  [1] ; ;  [2]
  1. Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433 (United States)
  2. University of Dayton, Department of Physics, Dayton, Ohio 45469 (United States)
Publication Date:
OSTI Identifier:
22492383
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 9; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CONCENTRATION RATIO; CRYSTAL GROWTH; DOPED MATERIALS; ELECTRICAL PROPERTIES; GALLIUM ANTIMONIDES; HALL EFFECT; INDIUM ARSENIDES; LAYERS; MOBILITY; MOLECULAR BEAM EPITAXY; N-TYPE CONDUCTORS; P-TYPE CONDUCTORS; REDUCTION; SUBSTRATES; SUPERLATTICES; TEMPERATURE DEPENDENCE; VISIBLE RADIATION