Stable tin perovskite solar cells enabled by widening the time window for crystallization

Tin perovskite solar cells (TPSCs) are the most promising candidates for lead-free perovskite solar cells (PSCs). However, the poor crystallization and chemical stability of Sn perovskites are the two challenging issues for further application of TPSCs. Here, we present a strategy to stabilize CH(NH2)(2)SnI3 (FASnI(3)) perovskite enabled by an amine complex, CH3NH3I center dot 3CH(3)NH(2), which can hinder the major degradation issue caused by the oxidation of Sn2+ to Sn4+. The resulting Sn perovskite films exhibit enhanced crystallinity and stability in comparison with those made with conventional inorganic SnF2 additives. Finally, the device achieved a higher external quantum efficiency for charge extraction and a power conversion efficiency (PCE) of 9.53%, which maintained more than 90% of the initial efficiency after 1000 h of light soaking under the standard AM 1.5 G solar illumination.

Automated summary

A strategy to stabilize Sn perovskite enabled by an amine complex was proposed in this study, addressing the issues of poor crystallization and chemical stability of Sn perovskites. The resulting Sn perovskite films showed enhanced crystallinity and stability compared to those made with conventional additives. The device achieved a higher efficiency and maintained over 90% of the initial efficiency after 1000 hours of light soaking.