Stability of p-type conductivity in nitrogen-doped ZnO thin film

Abstract

The behavior of p-type conductivity in nitrogen-doped ZnO prepared by thermal oxidation of zinc oxynitride thin film was investigated. The sample exhibited a stable p-type characteristic in the darkness over a 1yr period after deposition. However, when the p-type sample was irradiated by 2.72eV photons, it underwent a classic-mixed conductivity transition from p type to n type. An anomalously thermal equilibrium process was observed. It took 24h for the persisted n type photoconductivity to fade away in the dark and transit back to original p type. A local potential fluctuation model was used to explain the transient electrical behavior.