Robin Nicholas

Abstract:

Detectors operating in the 2-3 μm range based on InxGa1-xSb for environmental sensing are investigated. The same detectors which require a low leakage current reverse biased diode are studied for this p-n junction and Schottky barrier diode structures. The p-n hetero-junction between an n-GaAs substrate and the p-GaSb active region showed very good rectification. Despite the large lattice mismatch of -7.8%, there is less than 10 μA dark current up to 4V reverse bias. Increasing the barrier height to p-GaSb from 0.22eV to 0.7eV with use of a thin layer of GaAs have been quite successful but the result was not repeatable, unlike those for the GaSb/GaAs p-n junction.