# Bridging Oxidation and Crystallization Pathways in Sn–Pb Perovskites for High‐Efficiency, Stable Solar Cells

## TL;DR

This review explores how to stabilize mixed tin-lead perovskite solar cells by addressing oxidation and crystallization issues, enabling high efficiency and long-term stability.

## Contribution

The paper provides an integrated framework linking oxidation and crystallization challenges in Sn–Pb perovskites, offering strategies for stable and efficient solar cells.

## Key findings

- Strategies like precursor redox control and molecular antioxidants improve stability and efficiency.
- Combining oxidation and crystallization solutions leads to >23% efficiency and thousand-hour stability.
- Interfacial engineering and vacancy suppression enhance device performance and durability.

## Abstract

All‐perovskite tandem solar cells (TSCs) have recently surpassed the 30% power conversion efficiency milestone, positioning mixed tin–lead (Sn–Pb) perovskite as indispensable narrow‐bandgap absorbers. Their optimal bandgap, reduced lead content, and solution processability make them promising for next‐generation photovoltaics. However, their widespread application is hindered by severe stability issues, primarily the facile oxidation of Sn2+ and crystallization mismatch between Sn‐ and Pb‐based phases. Distinct from existing reviews, this short review provides an integrated framework for the two fundamental bottlenecks of Sn–Pb perovskite—Sn2+ oxidation and Sn/Pb crystallization mismatch—linking mechanistic insights across precursor chemistry, thin‐film formation, and device operation. We summarize recent advances that enable efficiencies >23% together with thousand‐hour operational stability, and we outline future directions toward fully integrated, scalable, and commercialization‐relevant stability solutions.

This review summarizes recent progress in stabilizing mixed Sn–Pb perovskite solar cells by bridging two fundamental bottlenecks: Sn2+ oxidation and Sn/Pb crystallization mismatch. We highlight precursor redox control, molecular antioxidants, vacancy suppression, and interfacial engineering strategies that jointly regulate oxidation chemistry and crystallization kinetics, enabling high efficiency (>23%) and long‐term operational stability for narrow‐bandgap perovskite solar cells and all‐perovskite tandems.© 2026 WILEY‐VCH GmbH