用磁控溅射方法在Si衬底上制备了Al掺杂Mg2Si薄膜,通过X射线衍射仪(XRD)、扫描电镜(SEM)、原子 力显微镜(AFM)和分光光度计研究了掺杂含量对Mg2Si薄膜组分、表面形貌、粗糙度及 光学带隙值的影响。XRD结果表明随着Al掺杂量的增加,Mg2Si衍射峰先增强后减弱。SEM及AFM的结果表明随掺杂量的增加,结晶度 先增加后降低,晶粒尺寸减小,粗糙度先增加后降低。得到掺杂后薄膜 间接跃迁带隙范围为0.423～0.495 eV,直接跃迁带隙范围为0.72～0.748 eV,掺杂前薄膜间接跃迁带隙和直接跃迁带隙分别为0.53 eV、0.833 eV。

The Al-doped Mg2Si thin films on Si substrates are fabricated by magnetron sputtering method. Influences of doping levels on the compositions, surface topographies, roughness and optical band gap values of Mg2Si thin films are investigated with X-ray diffraction (XRD), scanning electron microscope(SEM), atomic force microscope(AFM) and spectrophotometer. XRD results show that the diffraction peaks of Mg2Si become stronger firstly, and then become weaker with increasing of Al doping amount. SEM and AFM results show that the crystallinity increases first and then decreases. Grain size decreases, and the roughness increases first and then decreases with increasing of Al doping level. The indirect transition band gap of the doped films ranges from 0.423 eV to 0.495 eV. The direct transition band gap ranges from 0.72 eV to 0.748 eV. The indirect and direct transition band gap are 0.53 eV and 0.833 eV before doping, respectively.