Realization of high detectivity mid-infrared photodiodes based on highly mismatched AlInSb on GaAs substrates

Abstract

We have systematically investigated highly mismatched AlInSb photodiodes grown on GaAs substrates operating in the mid-infrared range. A novel characterization method was introduced to analyze the recombination mechanism within an active layer of the devices, which revealed a high conductance stemming from the leaky behavior of dislocations. The introduction of a dislocation filter layer successfully reduced threading dislocations and improved resistance area product of photodiodes, leading to high detectivity at room temperature.