Temperature dependence performances of InAs/GaSb superlattice photodiode

In this communication we report on temperature dependence performances of short period InAs/GaSb pin superlattice (SL) photodiode grown by Molecular Beam Epitaxy on p-type GaSb substrate. SL symmetrical structure with 3 μm thick active region, adapted for detection in the MWIR domain with cutoff wavelength varying from 4.6 μm to 5.5 μm in the temperature range 80–300 K, was processed in mesa photodiode in order to perform dark current measurements as a function of temperature. Extracted from current–voltage characteristics, R0A products above 1 × 106 Ω cm2 at 80 K and around 0.15 Ω cm2 at 200 K were measured, and the quantitative analysis of the J–V curves allowed us to identify the dominant dark current mechanism in each operating temperature range. As a result, SL photodiode is dominated by generation–recombination (GR) processes at low temperature and becomes diffusion limited above 140 K. Such results are discussed and minority carrier lifetimes were extracted from J–V curve fitting.