AlGaN-Based Solar-Blind Schottky Photodetectors Fabricated on AlN/Sapphire Template

Abstract

We report AlGaN-based back-illuminated solar-blind Schottky-type ultraviolet photodetectors with the cutoff-wavelength from 280nm to 292nm without bias. The devices show low dark current of 2.1 × 10−6A/cm2 at the reverse bias of 5 V. The specific detectivity D* is estimated to be 3.3 × 1012cmHz1/2 W−1. To guarantee the performance of the photodetectors, the optimization of AlGaN growth and annealing condition for Schottky contacts were performed. The results show that high-temperature annealing method for Ni/Pt Schottky contacts is effective for the reduction of leakage current.