Abstract
Oxides could be candidates for buffer, passivation, or high-resistive (HR) layers in Cu(In,Ga)Se2 (CIGS) thin-film solar cells. From an industrial point of view, a high-rate and dry deposition method like sputtering would be the most favorable technique. This study presents results with the wide-bandgap material gallium oxide (Ga2O3) deposited by magnetron sputtering applied as a substitution for the traditional CdS buffer or the intrinsic ZnO (i-ZnO) HR layer. With state-of-the-art CIGS absorber layers, subject to a RbF post-deposition treatment, an ammonia rinsing of the CIGS surface before sputtering of X-ray amorphous Ga2O3 has mostly a positive impact on device performance reaching efficiencies up to 14%. An efficiency of 20.2% with anti-reflective coating was achieved with Ga2O3 applied as HR layer as substitution for i-ZnO in combination with a solution-grown CdS buffer and ZnO:Al as front contact. This result is comparable to the efficiency of 20.4% for the CIGS/CdS/i-ZnO/ZnO:Al reference cell.
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The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.
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Acknowledgments
We thank the CIGS team at ZSW for solar cell preparation. This project has received funding from the German Federal Ministry for Economic Affairs and Energy (BMWi) under contract number 03EE1059A within the EFFCIS-II project.
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Witte, W., Hempel, W., Paetel, S. et al. Influence of sputtered gallium oxide as buffer or high-resistive layer on performance of Cu(In,Ga)Se2-based solar cells. Journal of Materials Research 37, 1825–1834 (2022). https://doi.org/10.1557/s43578-022-00608-z
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DOI: https://doi.org/10.1557/s43578-022-00608-z