Modeling and simulation of heterojunction photovoltaic detector based on InAs 0.15Sb 0.85 for free space optical communication

Abstract

In this paper we report a theoretical model of InAs 1-xSb x based photovoltaic detector for characterising the device in respect of RA product, voltage responsivity, quantum efficiency, detectivity and noise equivalent power. The model takes into account all the dominant dark current components e.g., diffusion, generation-recombination and tunneling (both band-to-band and trap-assisted) of the detector. The life-time of the carriers has been modeled by considering the three dominant recombination mechanisms e.g., radiative (band-to-band), Shockley-Read-Hall (SRH) and Auger recombination. The detector is expected to find application in free space optical communication system in 8-11 uμm bands. Several researchers have already proposed that infrared region is best suited for free space optical wireless communication. The noise equivalent power (NEP) has been estimated to 3.35 x× 1O -11 WHz 1/2 for an equivalent load resistance of 1 M for operation at 77 K.