The origin of the enhanced optical absorption in hot wire microcrystalline silicon

被引：1

作者：

Diehl, F ^{[1
]}

Schröder, B ^{[1
]}

Oechsner, H ^{[1
]}

机构：

[1] Univ Kaiserslautern, Dept Phys, D-67653 Kaiserslautern, Germany

来源：

AMORPHOUS AND MICROCRYSTALLINE SILICON TECHNOLOGY-1998 | 1998年 / 507卷

关键词：

D O I：

10.1557/PROC-507-819

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The phenomenon of enhanced optical absorption in hot wire microcrystalline silicon (hw-mu c-Si:H) has been investigated with respect to the structural properties of the as deposited as well as annealed films. The influence of the structural properties on the absorption behavior is explained within the framework of a model. In this model the mu c-Si:H is assumed to consist of crystalline grains surrounded by grain boundaries embedded into an amorphous matrix. Because of the relaxation of the k-selection rule the absorption is supposed to be higher for the disordered grain boundaries than for the crystalline grains. The absorption coefficient or is derived from the superposition of the absorption coefficients for the amorphous, crystalline and grain boundary regions weighted by their appropriate volume fractions. According to experimental results it is furthermore assumed that the absorption of the grain boundary regions correlates with the hydrogen content of the films. The model is proven and confirmed by crucial experiments especially concerning the influence of the hydrogen content on the absorption coefficient. Other possible reasons that might influence the enhanced optical absorption such as strain induced changes of a and light scattering effects are also discussed and explicitely excluded by appropriate experiments to be the essential enhancement reasons.

引用

页码：819 / 824

页数：6

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