用光热偏转谱拟合计算研究非晶硅缺陷态及其稳定性

Defects and Stability of a-Si:H by Simulations of Photothermal Deflection Spectroscope

通过光热偏转谱（ＰＤＳ）研究了衬底温度对用超高频辉光放电（ＶＨＦ－ＧＤ）制备的ａ－Ｓｉ：Ｈ光学特性的影响。考虑了电子在缺陷态的相关统计，数字拟合各样品在不同亚稳状态下ＰＤＳ次带吸收谱（０．８～１．７ｅＶ）．获得带尾态，光能隙，缺陷态分布及相关能等电子态结构参数。结果表明，缺陷态分布随光照时间向能隙深处移动，相关能增加。在电中性条件下，用迭代法求出费米能级与电导率，与实验结果吻合较好。分析讨论所用计算模型的可靠性及实用性。

The stability of VHF-GD a-Si:H for different deposition temperatures has been investigated by photothermal defection spectroscopy(PDS).Parameters of the defects in a-Si:H,such as,correlation energy and density of gap states.have been obtained by the numerical simulation of PDS. The results indicate that the metastable defects shift toward to the deep of the gap and correlation energy increases with the light illumination time. The Fermi level and conductivity have been recursively calculated under the electroneutrality condition,which are in fairly agreement with the experiment.The validity and reality of the simulation have been discussed.