InAsSb∕GaSb heterostructure based mid-wavelength-infrared detector for high temperature operation

The properties of a midinfrared photodetector, based on a lattice matched n-N InAs0.91Sb0.09∕GaSb type-II heterostructure, were investigated. The relatively simple two layer structure shows very promising characteristics for sensitive and dual color infrared detection. I-V characteristics and spectral response were measured at the temperature range of 10–300K. High zero-bias resistance area product R0A of 2.5Ωcm2 was obtained at room temperature. The measured background limited infrared photodetection temperature was 180K corresponding to 4.1μm cutoff. Shot and Johnson noise limited detectivities corresponding to InAsSb absorption were measured to be 1.3×1010 and 4.9×109cmHz1∕2W−1 at 180 and 300K, respectively. An enhanced optical response with gain larger than unity was observed below 120K. Bias tunable dual color detection was demonstrated at all measured temperatures.