多层模型计算椭偏法测量的SiO_2/Si超薄膜厚度

采用不同的光学模型对厚度为6 nm,密度为2.2 g/cm3的理想SiO2薄膜理论曲线进行了拟合,得到了薄膜厚度的计算结果随所采取的薄膜密度变化的规律:选用更大的薄膜密度值进行拟合计算会得到更小的厚度结果,其趋势近似线性.参考GIXRR方法测量得到的薄膜物理结构的结果,给出了优化的拟合计算模型(薄膜密度为2.4 g/cm3、表面粗糙度为0.4 nm、界面粗糙度为0.3 nm),对于热氧化法制备的厚度小于10 nm的SiO2超薄膜,使用此模型进行拟合计算,可以得到比常规模型更为准确的厚度结果.采用优化的模型拟合了期望厚度为2,4,6,8,10 nm的SiO2超薄膜的SE实验曲线,得到的厚度结果分别为2.61,4.07,6.02,7.41,9.43 nm,与传统模型计算结果相比,分别降低了13.8%,10.3%,8.1%,7.3%和6.6%.

水浸腐蚀对SiO_2/Ag/SiO_2复合膜光学特性的影响

用蒸镀法制备了SiO2 Ag SiO2 复合膜 ,探讨了水浸腐蚀和薄膜厚度对该复合膜光学特性的影响。试验结果表明 :适当增加复合膜中SiO2 膜层的厚度不但可以提高SiO2 Ag SiO2 复合膜可见光的透光率 ,而且可以相对有效地防止复合膜进一步被氧化 ,提高SiO2 Ag SiO2

Absorption enhancement in thin film a-Si solar cells with double-sided SiO_2 particle layers

Light absorption enhancement is very important for improving the power conversion efficiency of a thin film a-Si solar cell. In this paper, a thin-film a-Si solar cell model with double-sided SiO2 particle layers is designed, and then the underlying mechanism of absorption enhancement is investigated by finite difference time domain（FDTD） simulation;finally the feasible experimental scheme for preparing the SiO2 particle layer is discussed. It is found that the top and bottom SiO2 particle layers play an important role in anti-reflection and light trapping, respectively. The light absorption of the cell with double-sided SiO2 layers greatly increases in a wavelength range of 300 nm-800 nm, and the ultimate efficiency increases more than 22% compared with that of the flat device. The cell model with double-sided SiO2 particle layers reported here can be used in varieties of thin film solar cells to further improve their performances.

硅片表面超薄氧化硅层厚度测量关键比对CCQM—K32

利用X射线光电子能谱技术，建立了硅片表面超薄氧化硅层厚度（小于10nm）准确测量方法。中国计量科学研究院参加了国际关键比对CCQM—K32，根据公布的国际关键比对结果，中国计量科学研究院的测量结果与参比的各国国家计量研究院的测量结果达到了等效一致，测量结果的不确定度为4．6％～7．0％。