UV Photodetector Based on Vertical (Al, Ga)N Nanowires with Graphene Electrode and Si Substrate

Abstract

As the key device in a UV warning system, a solid‐state UV photodetector has attracted great attention. Herein, a new UV photodetector structure based on vertical (Al, Ga)N nanowires with graphene electrode and Si substrate is designed and demonstrated. By graphene/vertical (Al, Ga)N nanowire array heterojunction, the rectifying characteristics of I–V curve are formed, and the dark current is 54 nA at −2 V bias. The fabricated device exhibits a responsivity of 0.176 mA W−1 at the bias of −2 V, as well as a stable switching characteristic. It is proposed that the photogenerated electrons and holes can reach positive and negative electrodes by diffusion or tunneling effect, even with thick AlN sections. This method can promote the implementation of low cost for UV photodetector with adjustable detection range nowadays.