Understanding ion migration suppression in all-inorganic mixed halide perovskites via tin-lead alloying

Le résumé fourni par la source

All-inorganic perovskites are advantageous in terms of improved thermal stability compared to organic-inorganic counterparts. However, the ion migration-induced hysteresis significantly undermines the long-term operational stability of all-inorganic perovskite solar cells (PSCs), particularly in mixed halide perovskites. Herein, we report that tin-lead (Sn-Pb) alloying for all-inorganic mixed halide perovskites can effectively inhibit the ion migration behavior, as comprehensively revealed by the time-of-flight secondary ion mass spectrometry (TOF-SIMS), optical microscopy and galvanostatic measurements. On one hand, the small-sized Sn2+ cations can tighten the lattice structure to enhance the Pb/Sn-X (X=I and Br) ionic bonds, thereby effectively immobilizing the halide ions. On the other hand, Sn substitution can significantly reduce anti-site defects, such as ICs and IPb, which are considered potential pathways for ion migration. With these advantages, ion migration is greatly suppressed in Sn-Pb alloyed inorganic perovskites, resulting in reduced hysteresis and improved operational stability of PSC devices.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.