Work

Achieving Seasonal Reproducibility in Wide‐Bandgap Sn‐Based Perovskite Solar Cells via Proton‐Locking Interface Engineering

Year: 2025

Type: article

Abstract: ABSTRACT The advancement of wide‐bandgap (WBG) Sn‐perovskite devices is substantially hindered by seasonal instability and limited reproducibility, primarily due to moisture‐induced over‐doping of PEDOT:PSS and Sn 2+ oxidation. Here, we introduce a hydrophobic proton‐locking interface engineering strategy by incorporating a novel S‐benzyl‐L‐cysteine (SBLC) molecule into PEDOT:PSS. The hydrophobic benzyl backbone, amine groups, and significant dipole moment of SBLC facilitate strong coordination with Sn 2+ , effectively preventing moisture ingress and stabilizing buried interfacial energetics. This multifunctional modulation suppresses defects and promotes uniform crystallization across varying humidity and seasonal conditions. The optimized Target device, based on a WBG Sn‐perovskite composition of PEA 0.10 FA 0.75 EA 0.15 SnI 2.15 Br 0.85 , achieves a power conversion efficiency of 11.50% and retains >80% of its average performance across 279 devices fabricated monthly over 11 months, thereby establishing the first seasonal reproducibility benchmark. Furthermore, this approach exhibits increased stability of various stress conditions and enables a record efficiency of 17.40% in all‐perovskite tandem devices featuring a WBG Sn‐perovskite. These findings provide a scalable pathway toward reproducible, tandem‐compatible, lead‐free photovoltaics.

Source: Advanced Energy Materials

DOI: 10.1002/aenm.202505598