Electrical and optical performance of InAs / AlSb / GaSb superlattice photodetector

Abstract

We report on electrical and optical performance of InAs/AlSb/GaSb type-II superlattice photodetectors. The detector structure is designed to operate in the MWIR domain with a cut-off wavelength of 4.3 µm at 125 K. The photodiode exhibits a dark current density of 1 x 10-10 A/cm2 with a corresponding differential resistance area product (RoA) of 6 × 106 Omega;cm2 at 77K and zero bias. We analysed dinamic resistance are product (RdA) vs inverse temperature curves in each operating temperature range. The results show that the SL photodiode reveals diffusion limited behaviour at high temperatures and becomes generation-recombination (GR) limited below 125 K. Such results are discussed with extracted minority carrier lifetimes from J-V curve fitting.