Low-frequency noise characteristics of GaN-based UV photodiodes with AlN/GaN buffer layers prepared on Si substrates

Nitride-based metal–semiconductor–metal ultraviolet (UV) photodetectors prepared on Si (1 1 1) substrate with stacked buffer layers were proposed and prepared. With 5 V applied bias, it was found that dark current of the fabricated device was only 7.95×10−12 A. With an applied bias of 10 V, it was found that peak responsivity was 0.06 A/W, corresponding to quantum efficiency of 21.2% while UV/visible rejection ratio was 244. With 5 V applied bias, it was found that noise equivalent power, NEP and detectivity, D*, of our detector were 1.70×10−13 W and 1.18×1013 cm Hz0.5 W−1, respectively.