Optimizing the Performance of CsPbI3-Based Perovskite Solar Cells via Doping a ZnO Electron Transport Layer Coupled with Interface Engineering

Man Yue; Jie Su; Peng Zhao; Zhenhua Lin; Jincheng Zhang; Jingjing Chang; Yue Hao

doi:10.1007/s40820-019-0320-y

Optimizing the Performance of CsPbI₃-Based Perovskite Solar Cells via Doping a ZnO Electron Transport Layer Coupled with Interface Engineering

Nanomicro Lett. 2019 Oct 18;11(1):91. doi: 10.1007/s40820-019-0320-y.

Authors

Man Yue^#¹, Jie Su^#², Peng Zhao¹, Zhenhua Lin¹, Jincheng Zhang¹, Jingjing Chang³, Yue Hao¹

Affiliations

¹ State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, Shaanxi Joint Key Laboratory of Graphene, School of Microelectronics, Xidian University, 2 South Taibai Road, Xi'an, 710071, People's Republic of China.
² State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, Shaanxi Joint Key Laboratory of Graphene, School of Microelectronics, Xidian University, 2 South Taibai Road, Xi'an, 710071, People's Republic of China. sujie@xidian.edu.cn.
³ State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, Shaanxi Joint Key Laboratory of Graphene, School of Microelectronics, Xidian University, 2 South Taibai Road, Xi'an, 710071, People's Republic of China. jjingchang@xidian.edu.cn.

^# Contributed equally.

Abstract

Interface engineering has been regarded as an effective and noninvasive means to optimize the performance of perovskite solar cells (PSCs). Here, doping engineering of a ZnO electron transport layer (ETL) and CsPbI₃/ZnO interface engineering via introduction of an interfacial layer are employed to improve the performances of CsPbI₃-based PSCs. The results show that when introducing a TiO₂ buffer layer while increasing the ZnO layer doping concentration, the open-circuit voltage, power conversion efficiency, and fill factor of the CsPbI₃-based PSCs can be improved to 1.31 V, 21.06%, and 74.07%, respectively, which are superior to those of PSCs only modified by the TiO₂ buffer layer or high-concentration doping of ZnO layer. On the one hand, the buffer layer relieves the band bending and structural disorder of CsPbI₃. On the other hand, the increased doping concentration of the ZnO layer improves the conductivity of the TiO₂/ZnO bilayer ETL because of the strong interaction between the TiO₂ and ZnO layers. However, such phenomena are not observed for those of a PCBM/ZnO bilayer ETL because of the weak interlayer interaction of the PCBM/ZnO interface. These results provide a comprehensive understanding of the CsPbI₃/ZnO interface and suggest a guideline to design high-performance PSCs.

Keywords: All-inorganic CsPbI3 perovskites; Doping; Interface engineering; Simulation; ZnO.