High-Performance Planar Perovskite Solar Cells with Negligible Hysteresis Using 2,2,2-Trifluoroethanol-Incorporated SnO2

Yigang Luan; Xiaohui Yi; Peng Mao; Yuanzhi Wei; Jing Zhuang; Ningli Chen; Tao Lin; Cheng Li; Jizheng Wang

doi:10.1016/j.isci.2019.06.004

High-Performance Planar Perovskite Solar Cells with Negligible Hysteresis Using 2,2,2-Trifluoroethanol-Incorporated SnO₂

iScience. 2019 Jun 28:16:433-441. doi: 10.1016/j.isci.2019.06.004. Epub 2019 Jun 11.

Authors

Yigang Luan¹, Xiaohui Yi², Peng Mao¹, Yuanzhi Wei¹, Jing Zhuang¹, Ningli Chen¹, Tao Lin³, Cheng Li², Jizheng Wang⁴

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China; University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
² Semiconductor Photonics Research Center, OSED, Department of Physics, Jiujiang Research Institute, Xiamen University, Xiamen, Fujian 361005, P. R. China.
³ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
⁴ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China; University of Chinese Academy of Sciences, Beijing 100049, P. R. China. Electronic address: jizheng@iccas.ac.cn.

Abstract

An efficient electron transport layer (ETL) between the perovskite absorber and the cathode plays a crucial role in obtaining high-performance planar perovskite solar cells (PSCs). Here, we incorporate 2,2,2-trifluoroethanol (TFE) in the commonly used tin oxide (SnO₂) ETL, and it successfully improves the power conversation efficiency (PCE) and suppresses the hysteresis of the PSCs: the PCE is increased from 19.17% to 20.92%, and the hysteresis is largely reduced to be almost negligible. The origin of the enhancement is due to the improved electron mobility and optimized work function of the ETL, together with the reduced traps in the perovskite film. In addition, O₂ plasma is employed to treat the surface of the TFE-incorporated SnO₂ film, and the PCE is further increased to 21.68%. The concept here of incorporating organic small molecules in the ETL provides a strategy for enhancing the performance of the planar PSCs.

Keywords: Energy Materials; Energy Storage; Molecules.