Suppression of phase segregation in wide-bandgap perovskites with thiocyanate ions for perovskite/organic tandems with 25.06% efficiency
Zhichao Zhang1, Weijie Chen1*（陈炜杰）, Xingxing Jiang2, Jianlei Cao1, Haidi Yang1, Haiyang Chen1, Fu Yang1,3, Yunxiu Shen1, Heyi Yang1, Qinrong Cheng1, Xining Chen1, Xiaohua Tang1, Shuaiqing Kang1, Xue-mei Ou1, Christoph J. Brabec3,4*, Yaowen Li1,5,6*（李耀文）& Yongfang Li1,5,7
1Laboratory of Advanced Optoelectronic Materials, Suzhou Key Laboratory of Novel Semiconductor-optoelectronics Materials and Devices, College ofChemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, China.
2Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha, China.
3Institute of Materials for Electronics and Energy Technology (i-MEET), Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany.
4Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (HI ERN), Erlangen, Germany.5Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, China.
6State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, China.
7Beijing National Laboratory for Molecular Sciences; CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China.
Nature Energy,2024,9, 592–601
Abstract:Mixed halide wide-bandgap perovskites are suitable for integration in tandem photovoltaics such as perovskite/organic tandem solar cells. However, halide phase segregation originating from halogen vacancy-assisted ion migration in wide-bandgap perovskites limits the device efficiency and lifetime. Here we incorporate pseudo-halogen thiocyanate (SCN) ions in iodide/bromide mixed halide perovskites and show that they enhance crystallization and reduce grain boundaries. Trace amount of SCN ions in the bulk enter the perovskite lattice, forming an I/Br/SCN alloy, and occupy iodine vacancies, blocking halide ion migration via steric hindrance. Taken together, these effects retard halide phase segregation under operation and reduce energy loss in the wide-bandgap perovskite cells. The resulting perovskite/organic tandem solar cell achieves a power conversion efficiency of 25.82% (certified 25.06%) and an operational stability of 1,000 h.
链接：https://www.nature.com/articles/s41560-024-01491-0
