射频辅助N掺杂ZnO薄膜的生长及其光电特性

Studies on the Growth and Photoelectric-properties of RF-assisted N Doped ZnO Films

在MOCVD设备中采用改进的射频辅助生长装置,通过裂解N2及N-Al共掺杂的方法进行ZnO的p型掺杂研究。通过二次离子质谱(SIMS)、X射线衍射(XRD)、原子力显微镜(AFM)、光致发光(PL)谱等方法分析了薄膜中N杂质的浓度,以及射频功率与晶体质量、表面形貌以及光学特性之间的关系,并与Al掺杂和N掺杂的ZnO薄膜进行对比。实验结果表明,N掺杂的浓度高达1020cm-3;N-Al共掺杂极大地增加了ZnO的成核速率,其主要原因是N离化所起的作用;N-Al共掺的ZnO薄膜显示出p型性质,而N掺杂的ZnO薄膜由于N原子处于非激活状态而呈现高阻,这说明N-Al共掺杂对ZnO中N原子的活化起到一定作用。

In past, many papers reported that it was difficult to obtain p-ZnO through N2 splitting. We studies the properties of ZnO films through N2 splitting and N-Al co-doping by our MOCVD system which was improved with RF assisted equipment. The data of SIMS showed that the N concentration reached to 102^20-21 cm^ -3 in ZnO films. On this basic, we have studied the growth and photoelectric-properties of N-Al co-doped ZnO films, the effect of RF power on the crystal quality, surface morphologies and optical properties, through XRD, AFM and PL methods, to compare the properties of N-Al co-doped ZnO films. The result of our experiments indicates that the growth rate of ZnO films increases with increasing N splitting, N-Al co-doped ZnO films display p-type property, but the resistance of N doped ZnO films was rather high which was caused by non-activated N in ZnO films, this revealed that the N-Al co-doping facilitates the activation of N in ZnO films.