Photo-Assisted VOC Detection by Transparent pn Junction

Abstract

The p-NiO/n-ZnO transparent pn heterojunction is prepared by RF magnetron sputtering technique and processed into a chemical sensor element by photolithography pattering and chemical etching process. Forward biased p-NiO/n-ZnO heterojunction sensor can detect VOCs at room temperature and its gas sensitivity is extremely enhanced with the assist of deep UV light incidence. Even if the testing gas is thermodynamically stable such as aromatic VOC, the p-NiO/n-ZnO heterojunction sensor can detect it with the concert mechanism involving “electric” and “photo” assistance.