Regulation of Photoelectric Properties of Heterojunction Device by Oxygen Adsorption on ZnO Surface

Abstract

An optoelectronic-gas-sensing integrated sensor based on ZnO nanopillars/p-Si (100) heterojunction was prepared via a hydrothermal growth and calcination and then Ag electrodes plated process. Electron traps generated by oxygen adsorption on ZnO surface affect both dark current and photocurrent of the device under negative bias by reducing the electron concentration. I–V curve characteristics revealed that oxygen adsorption on ZnO surface reduces electron concentration by about 1/3, which greatly reduces the dark current with a slight decrease of the photocurrent, resulting signal-to-noise ratio increased. This will provide a theoretical support for design a device integrating photoelectric sensing and gas sensing.