Hwang, Sun Kyung Park, So Jeong Park, Jae Hyun Yoon, Joo Ho Yu Cho, Jae Cho, Deok Ki Heo, Jaeyeong Kim, Gee Yeong Kim, Jin Young 2024-01-19T08:04:27Z 2024-01-19T08:04:27Z 2023-12-21 2024-04 1613-6810 https://pubs.kist.re.kr/handle/201004/113100 Cu2ZnSn(S,Se)(4) (CZTSSe) thin film solar cells are an attractive choice for a bottom cell of the low-cost and environmental tandem solar cells with perovskite. However, the progress in developing efficient perovskite/CZTSSe tandem solar cells has been hindered by the lack of high performance of the CZTSSe bottom cell. Here, an efficient CZTSSe bottom cell is demonstrated by adopting a facile and effective CsF treatment process. It is found that the CsF treatment not only facilitates grain growth and improves phase homogeneity by suppressing the detrimental deep-level defects and secondary phases, but also induces larger band bending and stronger drift force at the P-N junction. As a result, the carrier extraction/transport can be effectively accelerated, while reducing the interfacial recombination. These combined effects eventually result in a significant performance enhancement from 8.38% to 10.20%. The CsF-treated CZTSSe solar cell is finally applied to the mechanically-stacked perovskite/CZTSSe 4-terminal tandem cell by coupling a semi-transparent perovskite top cell, which exhibits the highest reported tandem efficiency of 23.01%. English Wiley - V C H Verlag GmbbH & Co. Cs-treatments in Kesterite Thin-Film Solar Cells for Efficient Perovskite Tandems Article 10.1002/smll.202307175 1 Small, v.20, no.16 Small 20 16 N scie scopus 001111184300001 2-s2.0-85178242454 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article RB PASSIVATION NA LI 4-terminal tandem CsF treatments Cu2ZnSn(S,Se)(4) solar cells electrodeposition perovskites