High-performance short-wavelength infrared photodetectors based on type-Ⅱ InAs/InAs_(1-x)Sb_x/AlAs_(1-x)Sb_x superlattices

摘要

A high-performance short-wavelength infrared n-i-p photodiode based on InAs/InAs_(1_x)Sb_x/ AlAs_(1-x)Sb_x type-Ⅱ superlattices on GaSb substrate has been demonstrated. The device is designed to have a 50% cut-off wavelength of ～1.8 μm at 300 K. The photodetector exhibited a room-temperature (300 K) peak responsivity of 0.47 A/W at 1.6 μm, corresponding to a quantum efficiency of 37% at zero bias under front-side illumination, without any anti-reflection coating. With an R × A of 285 Ω cm~2 and a dark current density of 9.6 × 10~(-5) A/cm~2 under -50 mV applied bias at 300K, the photodiode exhibited a specific detectivity of 6.45 × 10~(10)cm Hz~(1/2)/W. At 200K, the photodiode exhibited a dark current density of 1.3 × 10~(-8) A/cm~2 and a quantum efficiency of 36%, resulting in a detectivity of 5.66 × 10~(12)cm Hz~(1/2)/W.