Interface band gap engineering in InAsSb photodiodes

The optimization of an InAs0.91Sb0.09 based infrared detector has been performed. The importance of the interfaces between the active region and the contacts in generation recombination phenomena is demonstrated. The two sides of the active region are optimized independently through heterostructure band gap engineering. The use of an Al0.15In0.85As0.91Sb0.09 quaternary makes it possible reach a detectivity of 4.4x10(9) cm root Hz/W at 290 K and 1.4x10(10) cm root Hz/W at 250 K at 3.39 mu m, offering the perspective of a noncryogenic infrared imaging in the 3-5 mu m band with quantum detectors. (c) 2005 American Institute of Physics.