AlGaN/GaN Schottky Barrier Photodetector With Multi- ${\rm Mg}_{\rm x} {\rm N} _{\rm y}$ /GaN Buffer

AlGaN/GaN heterostructure Schottky barrier photodetector (PD) with multi-Mg_xN_y/GaN buffer was proposed and fabricated. Compared with AlGaN/GaN heterostructure PD prepared on conventional low-temperature GaN buffer, it was found that we can reduce dark leakage current by more than three orders of magnitude. It was also found that we can use the multi-Mg_xN_y/GaN buffer to suppress photoconductance gain, enhance UV-to-visible rejection ratio, reduce noise level and enhance the detectivity.