论文部分内容阅读
通过氮气等离子体辅助脉冲激光沉积(PLD)技术制备了氮掺杂氧化锌(ZnO∶N)薄膜。经过低温快速热退火(RTA)处理后,ZnO∶N薄膜呈现p型导电特性。利用X射线光电子能谱(XPS)、光致发光(PL)和霍尔测量对ZnO∶N薄膜中N的化学状态及其光学和电学性质进行了系列的研究。结果表明:所制得的p型ZnO∶N薄膜为高度补偿半导体;RTA工艺不仅可以激活薄膜中更多的N受主,还可以弱化由薄膜中的施主缺陷造成的自补偿效应。在低温PL光谱中观察到了3种与氮受主相关的光发射,并且通过自由电子-受主(FA)辐射复合光发射确定了薄膜中N受主的离化能(128 meV)。随着退火温度的升高,施主-受主对发射峰呈现了略微的红移现象,这可以通过势能波动模型加以理解。
Nitrogen doped zinc oxide (ZnO: N) films were prepared by nitrogen plasma assisted pulsed laser deposition (PLD). After annealing at low temperature (RTA), the ZnO: N film exhibits p-type conductivity. The chemical states and optical and electrical properties of N in ZnO:N thin films were studied by X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and Hall measurement. The results show that the p-type ZnO: N thin film is a highly compensated semiconductor. The RTA process not only activates more N acceptors, but also weakens the self-compensation effect caused by donor defects in the thin films. Three types of light emission associated with nitrogen acceptors were observed in the low temperature PL spectrum and the N-donor ionization energy (128 meV) in the film was determined by free electron-acceptor (FA) radiative recombination light emission. As the annealing temperature increases, the donor-acceptor shows a slight redshift of the emission peak, which can be understood by the potential energy fluctuation model.