Polymer Lewis Base for Improving the Charge Transfer in Tin-Lead Mixed Perovskite Solar Cells

Yanjun Xing; Zhiqiang Deng; Qiuxiang Wang; Jiaxing Xiong; Xiaohui Liu; Like Huang; Yuejin Zhu; Jing Zhang

doi:10.3390/nano14050437

Polymer Lewis Base for Improving the Charge Transfer in Tin-Lead Mixed Perovskite Solar Cells

Nanomaterials (Basel). 2024 Feb 27;14(5):437. doi: 10.3390/nano14050437.

Authors

Yanjun Xing¹, Zhiqiang Deng¹, Qiuxiang Wang¹, Jiaxing Xiong¹, Xiaohui Liu¹, Like Huang¹, Yuejin Zhu^{1

2}, Jing Zhang¹

Affiliations

¹ Department of Microelectronic Science and Engineering, Ningbo University, Ningbo 315211, China.
² School of Information Engineering, College of Science and Technology, Ningbo University, Ningbo 315300, China.

Abstract

The poor film stability of Sn-Pb mixed perovskite film and the mismatched interface energy levels pose significant challenges in enhancing the efficiency of tin-lead (Sn-Pb) mixed perovskite solar cells. In this study, polyvinylpyrrolidone (PVP) is introduced into the PVK perovskite precursor solution, effectively enhancing the overall stability of the film. This improvement is achieved through the formation of robust coordination bonds between the carbonyl (C=O) in the pyrrole ring and the undercoordinated Sn^II and Pb^II, thereby facilitating the passivation of defects. Furthermore, the introduction of PVP inhibits the oxidation of tin (Sn), thereby enhancing the n-type characteristics of the perovskite film. This adjustment in the energy level of the PVK perovskite film proves instrumental in reducing interface energy loss, subsequently improving interface charge transfer and mitigating device recombination. Consequently, perovskite solar cells incorporating PVP achieve an outstanding champion power conversion efficiency (PCE) of 21.31%.

Keywords: Sn-Pb mixed perovskite; defect passivation; energy level regulation; metal coordination.

Grants and funding

This work was supported by the Fundamental Research Funding for the Provincial Universities of Zhejiang and the K. C. Wong Magna Funding in Ningbo University, China.