Homogenized contact in all-perovskite tandems using tailored 2D perovskite

• 成果类型: Article
• 署名作者: Wang, Yurui; Lin, Renxing; Liu, Chenshuaiyu; Wang, Xiaoyu; Chosy, Cullen; Haruta, Yuki; Bui, Anh Dinh; Li, Minghui; Sun, Hongfei; Zheng, Xuntian; Luo, Haowen; Wu, Pu; Gao, Han; Sun, Wenjie; Nie, Yuefeng; Zhu, Hesheng; Zhou, Kun; Nguyen, Hieu T.; Luo, Xin; Li, Ludong; Xiao, Chuanxiao; Saidaminov, Makhsud I.; Stranks, Samuel D.; Zhang, Lijun; Tan, Hairen
• 署名单位: Nanjing University; Jilin University; University of Cambridge; University of Cambridge; University of Victoria; Australian National University; Chinese Academy of Sciences; Ningbo Institute of Materials Technology & Engineering, CAS
• 刊物名称: Nature
• ISSN/ISSBN: 0028-4113
• DOI: 10.1038/s41586-024-08158-6
• 发表日期: 2024-11-28
• 关键词: total-energy calculations; solar

摘要

The fabrication of scalable all-perovskite tandem solar cells is considered an attractive route to commercialize perovskite photovoltaic modules1. However, the certified efficiency of 1-cm2-scale all-perovskite tandem solar cells lags behind their small-area (approximately 0.05-cm2) counterparts2,3. This performance deficit originates from inhomogeneity in wide-bandgap (WBG) perovskite solar cells (PSCs) at a large scale. The inhomogeneity is known to be introduced at the bottom interface and within the perovskite bulk itself4,5. Here we uncover another crucial source for the inhomogeneity-the top interface formed during the deposition of the electron transport layer (ETL; C60). Meanwhile, the poor ETL interface is also a notable limitation of device performance. We address this issue by introducing a mixture of 4-fluorophenethylamine (F-PEA) and 4-trifluoromethyl-phenylammonium (CF3-PA) to create a tailored 2D perovskite layer (TTDL), in which F-PEA forms a 2D perovskite at the surface, reducing contact losses and inhomogeneity, and CF3-PA enhances charge extraction and transport. As a result, we demonstrate a high open-circuit voltage (Voc) of 1.35 V and an efficiency of 20.5% in 1.77-eV WBG PSCs at a square-centimetre scale. By stacking with a narrow-bandgap (NBG) perovskite subcell, we report 1.05-cm2 all-perovskite tandem cells delivering 28.5% (certified 28.2%) efficiency, the highest reported so far. Our work showcases the importance of treating the top perovskite/ETL contact for upscaling PSCs. Using a mixture of 4-fluorophenethylamine and 4-trifluoromethyl-phenylammonium to create a tailored 2D perovskite layer reduces the inhomogeneity at the top interface of all-perovskite tandem cells and results in the highest efficiency reported so far.