Optimization of the absorber layer for a-Si:H and a-Si1-xGex:H single-junction solar cells

Abstract

This paper focuses on the optimization of the absorber layers in single-junction a-Si:H and a-Si1-xGex:H solar cells. For a-Si:H thin-film solar cells, we have found the electrode-to-substrate (E/S) spacing is an important parameter. By optimizing the E/S spacing, the cell effi-ciency was improved from 7.62% to 8.70% due to an improvement in material quality and JSC. For a-Si1-xGex:H solar cells, by optimizing the Ge-content, the microstructure parameter and the graded bandgap, we were able to improve the cell efficiency to 8.15%. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim