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实验测得的α-Si:H 中悬挂键能级相对于迁移边 E_C 的位置很不一致,分散于0.9—1.3eV 之间,本文用量子化学 EHT 方法对这一重要实验问题进行了计算。首先对 EHT 方法所用参数进行了优化选择处理,并对各种不同组态环境下的悬挂键能级进行了计算。结果表明,α-Si:H 中的悬挂键能级位置随环境原子排列的无序度不同而明显变化,由此推论:α-Si:H 中的悬挂键因能级位置相对于费米能级不同可以有三种荷电状态 T_3~+、T_3~-和 T_3~°,它们在空间上是相互分离的。据此,许多与悬挂键有关而长期存在的问题可以得到解释。
The experimentally measured α-Si: H dangling bond level relative to the migration edge E_C position is very inconsistent, scattered in the 0.9-1.3eV between the quantum chemical EHT method of this important experimental issues were calculated. Firstly, the parameters used in the EHT method were optimized and selected, and the dangling bond energy levels under various configurations were calculated. The results show that the position of dangling bond in α-Si: H changes obviously with the degree of disordering of the atoms in the environment. Therefore, the dangling bond in α-Si: H due to energy level position relative to Fermi energy Different levels can have three states of charge T_3 ~ +, T_3 ~ - and T_3 ~ °, which are spatially separated from each other. Accordingly, many long-standing problems related to dangling bonds can be explained.