中文摘要：

采用溶胶-凝胶技术在Pt/Ti/SiO_2/Si衬底上制备了不同镧掺杂浓度BiGaO_3（Lx BGO,0≤x≤0.1）薄膜.X-射线衍射（XRD）表明该属于正交晶系的多晶薄膜,原子力显微镜（AFM）图像显示样品表面具有很好的平整性.采用椭圆偏振技术对其光学性质进行了详细的研究,发现其光学常数符合Adachi色散模型.进一步发现其禁带宽度随着镧掺杂浓度的增加而增加,该规律与理论预言相吻合.有关LxBGO材料的研究为铋基光电器件如紫外探测器的实现提供物理基础支持.

英文摘要：

La doped BiGaO_3（LxBGO） films were fabricated by the Sol-Gel method on the Pt/Ti/SiO_2/Si substrates. Xray diffraction analysis shows that the films are polycrystalline with an orthorhombic structure. The atomic force microscopy images of the Lx BGO films suggest that the surface morphology is smooth. The optical properties of the samples were investigated by the spectroscopic ellipsometry in detail. The dielectric functions were extracted and in good agreement with the Adachi dispersion function. More one step,the optical band gap tends to increase with increasing La composition,which is consistent with the results of theoretical prediction. These results are helpful for the fabrication of Bibased opto-electrical devices such as ultraviolet detectors.