Effects of La doping on Mg₂Si semiconductor thin films prepared by thermal evaporation

La doped Mg₂Si semiconductor thin films were prepared on n-Si (111) substrate by thermal evaporation. The structure, morphology and optical properties of La doped Mg₂Si thin films were investigated by x-ray diffractometer (XRD), field-emission scanning electron microscopy (FESEM) and Raman spectrometer (RAMAN). XRD results show that after doping La, the Mg₂Si diffraction peak decreases and shifts to a low angle, and the lattice constant increases. FESEM results show that after doping La, the size of Mg₂Si crystallite decreases and the crystallites aggregate into clusters. RAMAN results show that the intensity of characteristic Raman peaks near 256 and 690 cm⁻¹ decreases after incorporation of La. (paper)