Buried SnI2 Induces Gradient Heterojunctions in Sn–Pb Perovskite Solar Cells
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 SnI2 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.
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, Beijing Key Laboratory of Energy Safety and Clean Utilization
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, Beijing Key Laboratory of Energy Safety and Clean Utilization
EPFL
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, Beijing Key Laboratory of Energy Safety and Clean Utilization
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, Beijing Key Laboratory of Energy Safety and Clean Utilization
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, Beijing Key Laboratory of Energy Safety and Clean Utilization
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, Beijing Key Laboratory of Energy Safety and Clean Utilization
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, Beijing Key Laboratory of Energy Safety and Clean Utilization
Key Laboratory of Photovoltaic and Energy Conservation Material, Institute of Solid-State Physics (ISSP)
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, Beijing Key Laboratory of Energy Safety and Clean Utilization
2025-04-03
10
2084
2092
REVIEWED
EPFL