Mn掺杂ZnO薄膜的结构及光学性能研究

Structure and optical properties of Mn doped ZnO thin films

通过脉冲激光沉积(PLD)法在SiO2基片上制备了不同含量的Mn掺杂ZnO薄膜.X射线衍射、X射线能谱、原子力显微镜与紫外-可见分光光度计测试结果表明:少量的Mn离子的掺杂并没有改变薄膜的结构,薄膜具有(103)面的择优取向;PLD法制备的ZnO薄膜的成分与靶材基本一致,实现了薄膜的同组分沉积;薄膜表面比较平坦,起伏度小于80nm,颗粒尺寸主要集中在25nm附近;但是Mn离子的掺杂改变了ZnO薄膜的禁带宽度,随Mn掺杂含量的增加,ZnO薄膜的禁带宽度增加;当薄膜中Mn含量从6%增加到12%时,薄膜对紫外强吸收区的光吸收能力也随之增加.

Mn-doped ZnO thin films were prepared on SiO2 substrate using pulsed laser deposition （PLD） technique in order to investigate the structure and optical properties of the films. XRD, AFM, EDX analysis and UV-VIS spectrophotometry were employed to characterize the Mn-doped ZnO films. The results showed that the shape of the XRD spectrum was remarkably similar to that of the un-doped ZnO film, indicating that the structure of the films was not disturbed by Mn-doping and the film also had mainly （103） peaks. The contents of （Zn, Mn）O thin films prepared by PLD were consistent with the targets, thus realizing the thin films deposition with same constitutuents as the target. The films had rather flat surfaces with the peak-to-tail roughness of about 80nm and an average grain diameter of about 25nm. Mn-doping changed the band gap of the films, which increased with the increase of the Mn content. Moreover, when the Mn content increased from 6% to 12 %, the absorbence in strong UV absorption band increased too.