基片温度对氧化铋薄膜光学性质的影响

Effect of Substrate Temperature on Optical Properties of Bismuth Oxide Thin Films

在玻璃基片上直流磁控溅射沉积氧化铋薄膜,基片温度从室温增加到300℃并保持其它沉积条件一致,研究基片温度对薄膜光学性能的影响.样品的晶体结构、表面形貌和透射光谱分别用X射线衍射仪、原子力显微镜和分光光度计进行测量.结果表明,随着基片温度的增加,样品中Bi2O3的（120）衍射峰强度增强,表面颗粒直径逐渐减小;基片温度为250,300℃样品出现了Bi2O2.75的（006）衍射峰.采用拟合透射光谱数据的方法计算薄膜的折射率、消光系数及厚度,并求出光学带隙.随基片温度的增加,氧化铋薄膜的折射率减小,消光系数在10-2~10-1数量级,光学带隙在3.51~3.04 eV递减.

Bismuth oxide films were deposited on glass substrates by direct current magnetron sputtering and the substrate temperature was changed from RT to 300 ℃.The effect of substrate temperature on the optical properties of the films was investigated.The microstructure,surface morphology and transmittance of the films were measured by X-ray diffraction,atomic force microscopy and spectrophotometer,respectively.Experimental results showed that the intensity of Bi2O3（120） peak became stronger and the surface particle size become smaller as the increasing of substrate temperature,Bi2O2.75（006） peak appeared when the substrate temperatures were 250 ℃ and 300 ℃.The refractive index,extinction coefficient and film thickness of the films were calculated by fitting transmittance spectrum data,and then optical band gap was calculated.The results showed that with the increasing of temperature the refractive index was smaller,and extinction coefficient ranged between 10-2 and 10-1.The optical band gap decreased between 3.51 eV and 3.04 eV.