用热激电导谱确定非晶态半导体能隙态密度的研究

AN INVESTIGATION OF DENSITY OF GAP STATES IN AMORPHOUS SEMICONDUCTORS BY THERMOSTI-MULATED CONDUCTIVITY SPECTRA

本文用较完整的热激电导理论分析方法,处理非晶态半导体的热激电导谱,获得a-Si:H薄膜和a-Si:H/a-SiN_x:H超晶格中能隙上半部缺陷态密度的分布。其结果与用Fritzsche的理论分析方法获得的态密度分布一致。进一步比较了两种处理方法的主要特点,讨论了它们的特征参量,最大热发射能级E_m与准费密能级E_q之间的关系。结果证明,a-Si:H热激电导的分析应用弱复合情况处理,热激载流子的再俘获不能忽略。表明Gu等人的理论分析进一步改进了对非晶态半导体热激电导谱的处理。

Determination of the density of states in the uper half of gap in a-Si:H film and a-Sir H/a-SiNx: H superlattices were obtained by a more comprehensive theoretical analysis of the thermostimulated comductivity. The results are consistent with that of Fritzsche's analysis. The main features of the two different analytical approaches and the correlation between maximnm chermostimulated current emission energy Em and quasi-Fermi level were discussed. The results show that the thermostimulated conductivity in a-Si: H should be analysed in weak recombination condition. In consequence, retrapping of the thermostimulated carriers can not be negleted. Theory of Gu et al. improves the analysis of measurement of thermostimulated conductivity.