Enhancement in Peak Detectivity and Operating Temperature of Strain-Coupled InAs/GaAs Quantum Dot Infrared Photodetectors by Rapid Thermal Annealing

We report the effects of rapid thermal annealing on the optical, structural, and device properties of 30 layer strain-coupled InAs/GaAs quantum dot infrared photodetectors. Stability in the photoluminescence peak is observed for annealing up to 800°C, which has not been previously reported. Cross-sectional transmission electron microscopy images show preservation of quantum dots is observed up to 800°C. Device with total capping thickness of 150 nm annealed at 750°C exhibit a fivefold enhancement in spectral intensity compared to as-grown devices and increase in the temperature of detector operation is observed from 100 to 140 K from the same device. The annealed devices exhibited a single-order enhancement in peak detectivity compared to as-grown quantum dot infrared photodetector.