Bound-to-extended state absorption GaAs superlattice transport infrared detectors

Abstract

We demonstrate an efficient 10-μm detector based on localized bound-state–to–extended-continuum-state absorption in doped GaAs/AlxGa1−xAs quantum wells designed to contain only one bound state. The voltage dependence of the responsivity is strikingly different from previous intersubband tunneling detectors containing two bound states. This results from the photoexcited electrons being transported over the top of the superlattice barriers, rather than tunneling through them.