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InAsSb Strain-Balanced Avalanche Photodiodes with 4-5 micron Cutoff Wavelength

Award Information

Department of Defense
Air Force
Award ID:
Program Year/Program:
2004 / STTR
Agency Tracking Number:
Solicitation Year:
Solicitation Topic Code:
Solicitation Number:
Small Business Information
Spire Corporation
One Patriots Park Bedford, MA 01730-2396
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Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
Phase 1
Fiscal Year: 2004
Title: InAsSb Strain-Balanced Avalanche Photodiodes with 4-5 micron Cutoff Wavelength
Agency / Branch: DOD / USAF
Contract: FA9550-04-C-0145
Award Amount: $99,906.00


Spire Corporation, through its Bandwidth Semiconductor subsidiary and in collaboration with colleagues in the Electrical Engineering Department at Boston University, proposes the metal-organic chemical vapor deposition (MOCVD) epigrowth of indium arsenide antimonide (InAsSb) avalanche photodiodes (APDs) ~2mm in diameter that should prove useful in laser radar and free-space communications. One particular composition (InAs90%Sb10%) is lattice-matched to GaSb wafers and would be used as a separate absorption region in this uncooled APD with a cutoff wavelength of about 4.4microns. The avalanche region would be in a homojunction in the higher bandgap GaSb. A thin two-compositional-step grading layer of InGaAsSb will help photogenerated carriers in the InAsSb absorption region reach the GaSb multiplication region by presenting smaller energy band transitions. This simpler lattice-matched separate absorption, grading, and multiplication region (SAGM) APD structure with a useful 4.4micron cutoff will serve as the experimental control to compare its performance with that of a strain-balanced APD using alternately tensile and compressive InAsSb layers with the goal of extending the cutoff wavelength from 4.4 to 5microns.

Principal Investigator:

Steven Wojtczuk
Senior Scientist,

Business Contact:

Mark C. Little
CEO, Spire Biomedical, Inc.
Small Business Information at Submission:

One Patriots Park Bedford, MA 01730

EIN/Tax ID: 042457335
Number of Employees:
Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
Research Institution Information:
Boston University
8 Saint Mary's Street
Boston, MA 02215
Contact: Selim Unlu
Contact Phone: (617) 353-5067
RI Type: Nonprofit college or university