Buried SnI2 Induces Gradient Heterojunctions in Sn–Pb Perovskite Solar Cells
Year: 2025
Type: article
Abstract: Tin–lead (Sn–Pb) mixed perovskite solar cells (PSCs) offer the potential for higher power conversion efficiency (PCE) than their pure lead counterparts. However, the lack of a well-defined Sn/Pb compositional profile results in disordered internal electric fields, limiting carrier separation. Here, we introduce a SnI 2 predeposition strategy that induces a vertical Sn/Pb composition gradient within the perovskite film. This gradient forms a continuous heterojunction, establishing a built-in electric field that enhances carrier separation and directional extraction. As a result, the optimized devices achieve a PCE of 23.2% along with improved stability, retaining 89.6% of their initial efficiency after 1032 h of storage in nitrogen. This work demonstrates a compositional and interfacial engineering approach for advancing the efficiency and durability of Sn–Pb mixed PSCs.
Source: ACS Energy Letters
Authors: Xuewei Liu, Jia Xu, Chenxu Zhao, Fan Shen, Pengchen Zou, Yijun Wang, Bozhang Ji, Xingjie Guan, Xu Pan, Jianxi Yao
Institutions: North China Electric Power University, State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, École Polytechnique Fédérale de Lausanne, Chinese Academy of Sciences, Hefei Institutes of Physical Science, Institute of Solid State Physics, Institute of Solid State Physics, UL
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Award: G1980891696
OpenAlex ID: W4409141985