Cuboid GaN/AlGaN Quantum Dot Infrared Photodetector; Photoconductive gain and capture probability

We have carried out a detailed theoretical analysis for a Quantum Dot (QD) Infrared Photodetector (QDIP). A cuboid GaN QD embedded in Al0.2Ga0.8N has been considered as the unit cell of the active layer of the detector. We started with calculating the electronic structure of the dots, using the single band effective mass method. Quantum efficiency has been discussed subsequently by considering its temperature, QD size and density dependency. Photoconductive gain and capture probability of the device has been mentioned as another main objective of this paper. Their different structural and external applied dependencies calculated and compared with previous experimental and theoretical reports. It is found that the gain can indeed exhibit abroad range of values including up to several thousands, depending on bias, in the considered structure. Eventually, Responsivity of the detector considered as a figure of merit and discussed by detail.