Light-induced changes in hydrogen-diluted a-Si : H materials and solar cells: A new perspective on self-consistent analysis

Abstract

We report a study on a-Si: H materials and p(a-SiC : H)/i(a-Si : H)/n(μc-Si) solar cells prepared without and with hydrogen dilution (10 : 1) at substrate temperatures between 240°C and 130°C. In contrast to previously reported studies, the cell characteristics in the annealed state of these ∼4000 Å thick cells could be directly correlated with the properties of their corresponding i-layer materials. Also, despite the importance of the p/i interface regions, very similar kinetics of light-induced changes are observed in the cells and the corresponding films. In particular, both cells and films fabricated with hydrogen dilution reach a degraded steady state in less than 100 h of AM 1 illumination, which offers a well-defined “marker” for the direct correlation of their respective light-induced changes. Advantage is also taken of the differences in degradation kinetics between diluted and undiluted materials in fabricating custom-designed cells in which these well-characterized intrinsic materials are incorporated into either the bulk or the p/i interface regions.