论文部分内容阅读
使用超高真空PECVD薄膜沉积系统制备的纳米桂薄膜（nc－Si：H）具有高电导特性。为了探讨其导电机制，先使用K．Yoshida早期提出的两相无序结构有效电导模型分别对晶粒电导和界面电导进行了理论计算。指出，nc－Si：H股中高电导主要来自于细微晶粒的传导，界面可视之为非导体。另一方面，实验证实nc－Si：H股的电导率随平均品粒尺寸减少而增大，具有明显的小尺寸效应。文中首次提出，nc－Si：H膜的微晶粒具有异质结量子点（HQD）特性，并按此模型对nc－Si：H膜的电导率实验曲线进行了讨论。理论与实验结果符合得很好．又得出，硅薄膜结构在其晶态体积百分比Xc=0．30和0．70处呈现出两个明显的相变点。
Nanocapsule films (nc-Si: H) fabricated using ultra-high vacuum PECVD film deposition systems have high conductivity. In order to explore the conductive mechanism, first use K. Yoshida’s earlier proposed effective conductivity model for two-phase disordered structures respectively calculated the grain conductivity and interfacial conductance. Pointed out that, nc-Si: H shares in the high conductivity mainly from fine grain conduction, the interface can be regarded as non-conductor. On the other hand, the experiment confirmed that the conductivity of nc-Si: H strands increases with the decrease of the average size of the nodules, which has obvious small size effect. It is proposed for the first time that the microcrystalline grains of the nc-Si: H film have the characteristics of a heterojunction quantum dot (HQD), and the conductivity curve of the nc-Si: H film is discussed according to the model. The theoretical and experimental results are in good agreement. It is also concluded that the silicon thin film structure exhibits two distinct phase transformation points at its crystalline volume percentages of Xc = 0.30 and 0.70.