Reducing the interfacial defect density of CZTSSe solar cells by Mn substitution
Cation disorder which arises from the size and chemical environment similarity of Cu and Zn is the limiting factor in Cu2ZnSnSxSe4−x (CZTSSe) performance. Cation substitution is one effective way to solve this issue, however, the most commonly reported substitutes, Ag and Cd, are not ideal as they d...
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sg-ntu-dr.10356-1408082021-01-18T04:50:18Z Reducing the interfacial defect density of CZTSSe solar cells by Mn substitution Lie, Stener Tan, Joel Ming Rui Li, Wenjie Leow, Shin Woei Tay, Ying Fan Bishop, Douglas M. Gunawan, Oki Wong, Lydia Helena School of Materials Science and Engineering Engineering::Materials Interfacial Defect Density CZTSSe Solar Cells Cation disorder which arises from the size and chemical environment similarity of Cu and Zn is the limiting factor in Cu2ZnSnSxSe4−x (CZTSSe) performance. Cation substitution is one effective way to solve this issue, however, the most commonly reported substitutes, Ag and Cd, are not ideal as they detract from the earth-abundant and non-toxic motivation of CZTSSe. Mn is a promising candidate in comparison with other candidates (e.g. Fe, Ni or Co), because of its oxidation state stability and larger ionic size mismatch with Cu. In this study, Cu2MnxZn1−xSn(S,Se)4 (CMZTSSe) thin film solar cells were prepared by chemical spray pyrolysis and a subsequent selenization process. We study the influence of Mn substitution on the morphological, structural, optical, electrical and device properties. A distinct phase transformation from CZTSSe kesterite to C(M,Z)TSSe stannite is observed at 20% Mn substitution. A high amount of Mn substitution (x ≥ 0.6) is shown to increase the carrier density significantly which introduces more defects and non-radiative carrier recombination as shown by quenched photoluminescence intensity. Consequently, reduction in device performance is observed for these samples. The highest power conversion efficiency is achieved at x ≈ 0.05 with η = 7.59%, Voc = 0.43 V, Jsc = 28.9 mA cm−2 and FF = 61.03%. The improved open circuit voltage (Voc) and fill factor (FF) are attributed to the improved shunt resistance and carrier transport due to low defect density especially at the CdS/CMZTSSe interface. Finally, based on our electrical characterization, a few suggestions to improve the efficiency are proposed. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) 2020-06-02T04:56:04Z 2020-06-02T04:56:04Z 2017 Journal Article Lie, S., Tan, J. M. R., Li, W., Leow, S. W., Tay, Y. F., Bishop, D. M., . . . Wong, L. H. (2018). Reducing the interfacial defect density of CZTSSe solar cells by Mn substitution. Journal of Materials Chemistry A, 6(4), 1540-1550. doi:10.1039/c7ta09668b 2050-7488 https://hdl.handle.net/10356/140808 10.1039/c7ta09668b 2-s2.0-85041236964 4 6 1540 1550 en Journal of Materials Chemistry A https://doi.org/10.21979/N9/CMBI4U © 2018 The Royal Society of Chemistry. All rights reserved. |
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Engineering::Materials Interfacial Defect Density CZTSSe Solar Cells Lie, Stener Tan, Joel Ming Rui Li, Wenjie Leow, Shin Woei Tay, Ying Fan Bishop, Douglas M. Gunawan, Oki Wong, Lydia Helena Reducing the interfacial defect density of CZTSSe solar cells by Mn substitution |
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Cation disorder which arises from the size and chemical environment similarity of Cu and Zn is the limiting factor in Cu2ZnSnSxSe4−x (CZTSSe) performance. Cation substitution is one effective way to solve this issue, however, the most commonly reported substitutes, Ag and Cd, are not ideal as they detract from the earth-abundant and non-toxic motivation of CZTSSe. Mn is a promising candidate in comparison with other candidates (e.g. Fe, Ni or Co), because of its oxidation state stability and larger ionic size mismatch with Cu. In this study, Cu2MnxZn1−xSn(S,Se)4 (CMZTSSe) thin film solar cells were prepared by chemical spray pyrolysis and a subsequent selenization process. We study the influence of Mn substitution on the morphological, structural, optical, electrical and device properties. A distinct phase transformation from CZTSSe kesterite to C(M,Z)TSSe stannite is observed at 20% Mn substitution. A high amount of Mn substitution (x ≥ 0.6) is shown to increase the carrier density significantly which introduces more defects and non-radiative carrier recombination as shown by quenched photoluminescence intensity. Consequently, reduction in device performance is observed for these samples. The highest power conversion efficiency is achieved at x ≈ 0.05 with η = 7.59%, Voc = 0.43 V, Jsc = 28.9 mA cm−2 and FF = 61.03%. The improved open circuit voltage (Voc) and fill factor (FF) are attributed to the improved shunt resistance and carrier transport due to low defect density especially at the CdS/CMZTSSe interface. Finally, based on our electrical characterization, a few suggestions to improve the efficiency are proposed. |
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School of Materials Science and Engineering |
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School of Materials Science and Engineering Lie, Stener Tan, Joel Ming Rui Li, Wenjie Leow, Shin Woei Tay, Ying Fan Bishop, Douglas M. Gunawan, Oki Wong, Lydia Helena |
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Article |
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Lie, Stener Tan, Joel Ming Rui Li, Wenjie Leow, Shin Woei Tay, Ying Fan Bishop, Douglas M. Gunawan, Oki Wong, Lydia Helena |
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Lie, Stener |
title |
Reducing the interfacial defect density of CZTSSe solar cells by Mn substitution |
title_short |
Reducing the interfacial defect density of CZTSSe solar cells by Mn substitution |
title_full |
Reducing the interfacial defect density of CZTSSe solar cells by Mn substitution |
title_fullStr |
Reducing the interfacial defect density of CZTSSe solar cells by Mn substitution |
title_full_unstemmed |
Reducing the interfacial defect density of CZTSSe solar cells by Mn substitution |
title_sort |
reducing the interfacial defect density of cztsse solar cells by mn substitution |
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2020 |
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https://hdl.handle.net/10356/140808 https://doi.org/10.21979/N9/CMBI4U |
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1690658442088284160 |