An improved analysis for band edge optical absorption spectra in hydrogenated amorphous silicon from optical and photoconductivity measurements

被引：43

作者：

Jiao, L ^{[1
]}

Chen, I ^{[1
]}

Collins, RW ^{[1
]}

Wronski, CR ^{[1
]}

Hata, N ^{[1
]}

机构：

[1] Penn State Univ, Dept Elect Engn, University Pk, PA 16802 USA

来源：

APPLIED PHYSICS LETTERS | 1998年 / 72卷 / 09期

关键词：

D O I：

10.1063/1.120963

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

The uncertainties inherent in the normalization of subgap photoconductivity spectra to the optical absorption spectra cr(hu) in a-Si:H based films have been addressed. An analysis is presented which is based on optical transitions of constant dipole matrix element between parabolic distributions of extended states and exponential distributions of localized tail states. This analysis has been used to normalize the two sets of results accurately, as verified by photothermal deflection spectroscopy measurements, and is shown to be useful in the commonly encountered cases, in which the two spectra do not overlap over an extended region. Improved quantitative fits of cr(hu), for photon energy from similar to 1.5 to 2.4 eV, obtained on different a-Si:H based films indicate that the localized exponential band tail regions extend similar to 60-70 meV above the optical gap. (C) 1998 American Institute of Physics.

引用

页码：1057 / 1059

页数：3

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