Demonstration of a large-area AlGaN/GaN Schottky barrier photodetector on Si with high detection limit

A high-quality AlGaN/GaN Schottky barrier photodetector was demonstrated on Si. The device exhibited a very low dark current of 0.94 fA at -2.5 V and 2.51 pA at -10 V. There were two spectral response peaks located at 280 and 340 nm, respectively, and the relative intensity of these peaks changed with applied bias. The responsivity exhibited optical power density dependence measured at 340 nm with different bias. The zero bias differential resistance of 3.63 x 10(13) Omega and area product is calculated to be 4.10 x 10(11) Omega cm(2). The excellent current-voltage characteristics led to a detectivity performance of 4.98 x 10(13) cm Hz(1/2) W-1.