Enhancing electron extraction and transport in inorganic perovskite solar cells via additional built-in potential of SnO2-BiFeO3 nano-heterostructure

• Published in: Chemical engineering science Vol. 288; p. 119839
• Main Authors: Zou, Yihui, Chang, Binbin, Lin, Changhong, Yuan, Yuqi, Hu, Haihua, Xu, Lingbo, Wang, Peng, Lin, Ping, Wu, Xiaoping, Cui, Can
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.04.2024
• Subjects: BiFeO3; CsPbI3; Electron transport layer; Heterostructure; Perovskite solar cell; Heterostructure; Perovskite solar cell; BiFeO3; CsPbI3; Electron transport layer
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2024.119839

A nano-heterostructure electron transport layer (ETL) is constructed by incorporating BiFeO3 nanoparticles with SnO2. The additional built-in potential generated in SnO2/BiFeO3 nano-heterostructure results in a significant improvement in electron extraction and transport rates within the CsPbI3 perovskite solar cells (PSCs). The best efficiency for devices based on SnO2-BiFeO3 ETL is up to 17.35% with the improved stability, suggesting the potential of BiFeO3 in further advancements of PSCs. [Display omitted] •SnO2-BiFeO3 electron transport layer with nano-heterostructure is constructed.•Additional built-in potential generated in SnO2/BiFeO3 nano-heterostructure boosts electron extraction and transport rates within the CsPbI3 perovskite solar cells (PSCs).•CsPbI3 PSCs based on SnO2-BiFeO3 with the highest efficiency of 17.35% are obtained. The electron transport layer (ETL) with excellent charge extraction and transport ability plays a crucial role in high-performance perovskite solar cells (PSCs). Here, we propose a approach to modify SnO2 ETL by introducing perovskite oxide BiFeO3 nanoparticles into SnO2 film to construct SnO2-BiFeO3 nano-heterostructure. The formation of SnO2-BiFeO3 nano-heterostructure within the SnO2 ETL introduces an additional built-in potential directed from SnO2 to BiFeO3, which provides an additional driven force for the charge carriers transfer. As a result, the extraction rate of electrons from the perovskite layer to the SnO2-BiFeO3 ETLs is significantly improved. In addition, an excellent ETL/perovskite interface with more favorable band alignment and fewer defects is achieved via the incorporation of BiFeO3 nanoparticles. By employing SnO2-BiFeO3 ETLs in CsPbI3 PSCs, we obtained PSC with a higher PCE of 17.35%, compared to 14.93% for the reference one. This result not only validates the effectiveness of BiFeO3 in improving the performance of SnO2-based PSCs but also highlights its potential application for other perovskite devices.