Passivation of 2D Cs2PbI2Cl2 Nanosheets for Efficient and Stable CsPbI3 Quantum Dot Solar Cells

Yueli Liu; Xiaolei Zhang; Zifan Yang; Keqiang Chen; Wen Chen

doi:10.1021/acsami.4c02917

Passivation of 2D Cs₂PbI₂Cl₂ Nanosheets for Efficient and Stable CsPbI₃ Quantum Dot Solar Cells

ACS Appl Mater Interfaces. 2024 May 1;16(17):22197-22206. doi: 10.1021/acsami.4c02917. Epub 2024 Apr 17.

Authors

Yueli Liu^{1

2}, Xiaolei Zhang¹, Zifan Yang¹, Keqiang Chen³, Wen Chen^{2

4}

Affiliations

¹ State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China.
² Sanya Science and Education Innovation Park, Wuhan University of Technology, Sanya 572024, P. R. China.
³ Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, P. R. China.
⁴ State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China.

PMID: 38632668
DOI: 10.1021/acsami.4c02917

Abstract

Inorganic CsPbI₃ perovskite quantum dots (PQDs) possess remarkable optical properties, making them highly promising for photovoltaic applications. However, the inadequate stability resulting from internal structural instability and the complex external surface chemical environment of CsPbI₃ PQDs has hindered the development of CsPbI₃ PQD solar cells (PQDSCs). In this work, the capping layer composed of inorganic two-dimensional (2D) Ruddlesden-Popper (RP) phase Cs₂PbI₂Cl₂ nanosheets (NSs) is introduced, which may be effectively treated to improve the surface properties of the CsPbI₃ PQD film. This modification serves to passivate defects by filling cesium and iodine vacancies while optimizing the energy band arrangement and preventing humidity intrusion, leading to the meliorative stability and photovoltaic performance. The optimized CsPbI₃ PQDSCs achieve an enhanced power conversion efficiency (PCE) of 14.73%, with the superb stability of only a 16% efficiency loss after being exposed to ambient conditions (30 ± 5% RH) for 432 h.

Keywords: CsPbI3 quantum dot solar cells; RP Cs2PbI2Cl2 nanosheets; energy band arrangement; passivation; stability.