Enhancing the Performance of ZnO Nanorod/p-GaN Heterostructured Photodetectors Using the Photoelectrochemical Oxidation Passivation Method

The n-ZnO/i-ZnO nanorod arrays were deposited on p-GaN layer using the vapor cooling condensation system. The photoelectrochemical system was used to directly grow thin Zn(OH)₂ layer for passivating sidewall surface of the ZnO nanorod arrays. The resultant surface leakage current, the thermal noise current, and the shot noise current of the passivated ZnO nanorod array photodetectors were reduced compared with the unpassivated ZnO nanorod array photodetectors. The mean square noise current of the passivated ZnO nanorod array photodetectors was smaller than that of the unpassivated ZnO nanorod array photodetectors. These experimental results verified that the reliability and stability of the passivated ZnO nanorod array photodetectors were improved compared with the unpassivated ZnO nanorod array photodetectors.