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Avalanche photodetector in the GaSb/AlSb/InAs material system by molecular beam epitaxy

Cheng, X-C. and McGill, T. C. (1999) Avalanche photodetector in the GaSb/AlSb/InAs material system by molecular beam epitaxy. In: Photodetectors: Materials and Devices IV. Proceedings of SPIE. No.3629. Society of Photo-optical Instrumentation Engineers (SPIE) , Bellingham, WA, pp. 268-278. ISBN 9780819430991.

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GaSb/AlSb/InAs is an attractive system for making low noise avalanche photodetectors (APD) due to possible resonant enhancement of hole impact ionization in Al_xGa_(1-x)Sb and potential enhancement of electron impact ionization in GaSb/AlSb superlattices. We have employed molecular beam epitaxy (MBE) to fabricate device structures so that these effects could be further explored. The devices were grown on GaSb substrates and incorporated a p^-n^+ one sided abrupt junction. The p^- multiplication region consisted of either bulk Al_(0.04)Ga_(0.96)Sb or 10 periods of alternating, 300 angstrom thick GaSb and AlSb layers. A short period, selectively doped InAs/AlSb superlattice was used as the n^+ layer. Dark current suppression in these devices was found to be largely dependent on the InAs/AlSb superlattice configuration and the resulting band offset at the p^-n^+ heterojunction. Notably, for devices with a 0.6 micrometer Al_(0.04)Ga_(0.96)Sb multiplication region and an optimized InAs/AlSb superlattice, an avalanche break down voltage of 13 V was observed. The dark current density for this device was 6 A/cm^2 at a multiplication factor of 10. Devices with GaSb/AlSb superlattice multiplication regions exhibited a higher breakdown voltage (18.5 V) and a lower dark current density (0.4 A/cm^2) at comparable gain. Impact ionization rates in Al_(0.04)Ga_(0.96)Sb were studied by using 781 nm and 1645 nm laser light. The results were consistent with enhancement of hole impact ionization in Al_(0.04)Ga_(0.96)Sb.

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Additional Information:© 1999 Society of Photo-optical Instrumentation Engineers (SPIE). The authors would like to thank A. T. Hunter and D. H. Chow of Hughes Research Lab for helpful discussions of antimonide growth and APD characterization. We also gratefully acknowledge the support of the Defense Advanced Research Projects Agency monitored by the Army Research Laboratory under contract number DAAL 01-97-K-0121.
Funding AgencyGrant Number
Defense Advanced Research Projects Agency (DARPA)UNSPECIFIED
Army Research Laboratory (ARL)DAAL 01-97-K-0121
Subject Keywords:Avalanche photodetector, Molecular beam epitaxy, AlGaSb, Superlattice, Dark current, Impact ionization
Series Name:Proceedings of SPIE
Issue or Number:3629
Record Number:CaltechAUTHORS:20181107-155256105
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Official Citation:Xiao-Chang Cheng, Thomas C. McGill, } "Avalanche photodetector in the GaSb/AlSb/InAs material system by molecular beam epitaxy", Proc. SPIE 3629, Photodetectors: Materials and Devices IV, (7 April 1999); doi: 10.1117/12.344563;
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:90732
Deposited By: Tony Diaz
Deposited On:08 Nov 2018 00:44
Last Modified:16 Nov 2021 03:35

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