Photovoltaic MWIR Type-II Superlattice Focal Plane Array on GaAs Substrate

Abstract

Recent improvements in the performance of type-II superlattice (T2SL) photodetectors has spurred interest in developing low-cost and large-format focal plane arrays (FPAs) on this material system. Due to the limitations of size and cost of native GaSb substrates, GaAs is an attractive alternative with 8 in wafers commercially available, but is 7.8% lattice mismatched to T2SL. In this paper, we present a photovoltaic T2SL 320 × 256 FPA in the mid-wavelength infrared on GaAs substrate. The FPA attained a median noise equivalent temperature difference of 13 and 10 mK (F# = 2.3) with integration times of 10.02 and 19.06 ms, respectively, at 67 K.