AlGaN-based ultraviolet photodetector with micropillar structures

We demonstrated a single AlGaN layer with two different Al contents on the GaN μ-pillars template. It was found by the selective wavelength spatial cathodoluminescence images that the emission wavelengths of the AlGaN layer were at 345 and 325 nm on the side of the cone and on the top and valley surface of pillars, respectively. The Schottky-type photodetectors were also demonstrated on double Al contents of deposited AlGaN on GaN micropillar templates. The three steps of responses occurred at about 326, 346, and 356 nm with responsivities of 1.1×10−2, 5.9×10−3, and 4.04×10−3 A/W, respectively.