ZnO nanowires array p-n homojunction and its application as a visible-blind ultraviolet photodetector

Abstract

We demonstrated a simple and low-cost fabrication of ZnO $p\text{-}n$ homojunction. The junction consists of $n$ -type ZnO nanowires array by a hydrothermal method covered with $p$ -type Al, N co-doped ZnO film by a sol-gel method. The junction exhibits good rectification characteristics, with reverse leakage current and rectification ratio of $\sim 5\mu \text{A}$ and $\sim 150$ at bias of 3 V, respectively. The junction is operated as a photodetector when light radiation is shined on the glass-side of the device. The photodetector shows a peak responsivity at 384 nm with UV-visible responsivity ratio $\left(R_{384\text{nm}}/R_{550\text{nm}}\right)$ of $\sim 70$ at an operating bias of −3 V.