Mid-wavelength infrared high operating temperature pBn photodetectors based on type-II InAs/InAsSb superlattice

Abstract

A high operating temperature mid-wavelength infrared pBn photodetector based on the type-II InAs/InAsSb superlattice on a GaSb substrate has been demonstrated. At 150 K, the photodetector exhibits a peak responsivity of 1.48 A/W, corresponding to a quantum efficiency of 47% at −50 mV applied bias under front-side illumination, with a 50% cutoff wavelength of 4.4 µm. With an R × A of 12 783 Ω cm2 and a dark current density of 1.16 × 10−5 A/cm2 under −50 mV applied bias, the photodetector exhibits a specific detectivity of 7.1 × 1011 cm Hz1/2/W. At 300 K, the photodetector exhibits a dark current density of 0.44 A/cm2 and a quantum efficiency of 39%, resulting in a specific detectivity of 2.5 × 109 cm Hz1/2/W.