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 ZnO (ZnO:N) films were grown by N-plasma assisted pulsed laser deposition.The ptype conductivities were achieved by post low-temperature rapid thermal annealing (RTA).The N chemical states,optical and electrical properties of ZnO:N films were systematically studied by X-ray photoelectron spectroscopy ( XPS),photoluminescence (PL) and Hall measurements.The results revealed that the obtained p-type ZnO:N films are highly compensated semiconductor,and the RTA process can activate more N acceptors and reduce the self-compensation of intrinsic donor defects.Three N acceptor-related emissions were observed in low-temperature PL spectra.The ionization energy of N acceptor was determined as about 128 meV from free-electron-to-acceptor (FA) transition.Interestingly,donor-acceptor pair (DAP) emission showed a slight redshift with increasing annealing temperature.This phenomenon was understood in terms of a potential fluctuation model.
展开▼
