Infrared detectors and lasers operating in the 3-12 um range using band-gap engineered structures with Type II band-gap alignment

The Type 11 broken band-gap alignment in semiconductor structures wherein the conduction band minimum is in one semiconductor (e.g., InAs) and the valence band maximum is in another (e.g., GaInSb) offers certain unique advantages which can be utilized to realize band-gap engineered novel quantum electro-optic devices such as lasers and detectors. The advantages of the type 11 structures include reduced Auger recombination, extending the effective band-gap energy of materials wherein type I band-gap alignment would give rise to difficulties such as miscibility gap. In this paper we describe the work carried out at the Army Research Laboratory on type 11 semiconductor quantum electro-optic devices such as IR lasers and detectors operating in the 3-12 um range. Specifically we will cover the progress made in GaSb based type 11 strained layer superlattice IR detectors and Interband Cascade IR Lasers. We will also present our recent work in self-assembled quantum dots which have type 11 band-gap alignment with the matrix material in which the dots are embedded.