1. Optical properties of Cu2ZnSn(SxSe1-x)(4) solar absorbers : Spectroscopic ellipsometry and ab initio calculations
- Author
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Li, Shu-yi, Zamulko, Sergiy, Persson, Clas, Ross, Nils, Larsen, Jes K., Platzer-Bjorkman, Charlotte, Li, Shu-yi, Zamulko, Sergiy, Persson, Clas, Ross, Nils, Larsen, Jes K., and Platzer-Bjorkman, Charlotte
- Abstract
Dielectric functions of Cu2ZnSn(SxSe1-x)(4) thin film absorbers with varied x were determined by spectroscopic ellipsometry and ab initio calculations. From the combination of experimental and theoretical studies, the fundamental interband transition energy E-0 (similar to 1-1.5 eV) and the next following transition energy E-1 (similar to 2-3 eV) were identified and found to blue-shift with increasing sulfur anion content, while keeping the energy separation E-1 - E-0 almost constant, similar to 1.4 eV from experiments, and 1 eV from theory. In addition, the average dielectric responses were found to decrease with sulfur anion content from both theoretical and experimental results. The Tauc optical bandgap value E-g determined on samples prepared on Mo and soda lime glass substrate showed a positive linear relationship between x and bandgap E-g. The bandgap bowing factor determined from the theoretical data is 0.09 eV., QC 20170306
- Published
- 2017
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