Performance improvement of longwave infrared photodetector based on type-II InAs/GaSb superlattices using unipolar current blocking layers

Abstract

We report here a heterojunction band gap engineered type-II InAs/GaSb strained layer superlattice photodiode for longwave infrared detection. The reported PbIbN architecture shows improved performance over conventional PIN design due to unipolar current blocking layers. At 77 K and Vb=−0.25 V, responsivity of 1.8 A/W, dark current density of 1.2 mA/cm2, single pass quantum efficiency of 23%, and shot noise limited detectivity (D∗) of 8.7×1010 cm Hz1/2 W−1 (λc=10.8 μm) were measured. The device demonstrated background limited performance at 100 K under 300 K for 2π field of view.