Spiro-OMeTAD Anchoring perovskite for gradual homojunction in stable perovskite solar cells

• Published in: Solid-state electronics 2024-11, Vol.221-222, p.109003, Article 109003
• Main Authors: Wang, Ziyi, Yuan, Bobo, Gao, Yiheng, Wu, Rui, Xiao, Shuping, Xiang, Wuchen, Yu, Xueli, Qin, Pingli
• Format: Article
• Language: English
• Subjects: Defect passivation; Homojunction interface; Perovskite solar cells; Spiro-OMeTAD
• ISSN: 0038-1101
• DOI: 10.1016/j.sse.2024.109003

Spiro-OMeTAD has been pipetted onto the spinning perovskite precursor film via a chlorobenzene anti-solvent strategy, then serves as not only the filler at grain boundaries, but also the coverage on perovskite’s grain to form the gradual homojunction interface from perovskite to spiro-OMeTAD hole transport layer, making spiro-OMeTAD anchor perovskite via the reaction between Pb2+ and C-O groups. This can obtain the optimal interface energy-level match between them and prevent moisture invading perovskite. Consequently, the counterpart PSC achieves a champion efficiency of 24.46%. [Display omitted] •Spiro-OMeTAD is introduced into perovskite precursor film to form a gradual homojunction.•Spiro-OMeTAD reacts with Pb2+ to anchor perovskite to smooth interface barriers.•Spiro-OMeTAD fills grain boundaries and covers perovskite for long-term stability.•The target device achieved a PCE of 24.46%, outperforming the control device.•The target device retains over 88 % of initial efficiency after 224 days. The role of interface energetics-modification in interface-defect passivation and optimal interface energy-level matching is assumed to be a crucial aspect. Enhancing the performance and durability of perovskite solar cells (PSCs) can be achieved through this strategy. Here, spiro-OMeTAD [2,2′,7,7′-tetrakis (N, N-di-p-methoxyphenylamine)-9,9′-spirobifluorene] has been pipetted onto the spinning perovskite precursor film via a chlorobenzene anti-solvent strategy. It is found that spiro-OMeTAD serves as not only the filler at grain boundaries, but also the coverage on perovskite’s grain, and then forms the gradual homojunction interface from perovskite to spiro-OMeTAD hole transport layer, which can make spiro-OMeTAD anchor perovskite via the reaction between Pb2+ and C-O groups to decrease the interface barrier and obtain the optimal interface energy-level match between them for hole −migration and −collection. Moreover, these fillers or coverages can prevent moisture invading perovskite. Consequently, the counterpart PSC achieves a champion efficiency of 24.46 %, and has retained more than 88 % of the initial efficiency after 224 days of storage.