Demonstration of shortwavelength infrared photodiodes based on type-Ⅱ InAs/GaSb/AlSb superlattices

摘要

We demonstrate the feasibility of the InAs/GaSb/AISb type-Ⅱ superlattice photodiodes operating at the short wavelength infrared regime below 3 μm. An n-i-p type-Ⅱ InAs/GaSb/AISb photodiode was grown with a designed cut-off wavelength of 2 μm on a GaSb substrate. At 150 K, the photodiode exhibited a dark current density of 5.6 × 10~(-8)A/cm~2 and a front-side-illuminated quantum efficiency of 40.3%, providing an associated shot noise detectivity of 1.0 × 10~(13) Jones. The uncooled photodiode showed a dark current density of 2.2 x 10~(-3)A/cm~2 and a quantum efficiency of 41.5%, resulting in a detectivity of 1.7 × 10~(10)Jones.