Characteristics of p-type ZnO:As thin films prepared by the ampoule-tube method and ZnO p–n homojunction

摘要

A p-type ZnO thin film was prepared using arsenic diffusion via the ampoule-tube method. This was followed by fabrication of a ZnO p–n homojunction using n-type ZnO and characterization of the device properties. The ZnO thin film exhibited p-type characteristics, with a resistivity of 2.19×10−3 Ω cm, a carrier concentration of 1.73×1020/cm3, and a mobility of 26.7 cm2/V s. Secondary ion mass spectrometer analysis confirmed that in- and out-diffusion occurred simultaneously from the external As source and the GaAs substrate. The device exhibited the rectification characteristics of a typical p–n junction; the forward voltage at 20 mA was approximately 5.5 V. The reverse-bias leakage current was very low—0.1 mA for −10 V; the breakdown voltage was −11 V. The ampoule-tube method for fabricating p-type ZnO thin films may be useful in producing ultraviolet ZnO LEDs and other ZnO-based devices. PACS 81.05.Dz - 51.20.+d - 81.20.Ka - 81.40.Rs - 73.40.Lq