Work

Sulfolane-Based Solvent Polishing of Perovskite Films for Optimized Solar Cells

Year: 2026

Type: article

Abstract: The complex crystallization of solution-processed polycrystalline perovskite films leads to the formation of deep-trap states, ultimately hindering the performance of perovskite solar cells (PSCs). Here, we have devised a facile and practical solvent polishing (SP) approach utilizing a sulfolane and chlorobenzene mixture to reconstruct the surface of triple-cation perovskite films. This strategy enables the removal of the surface-oriented phases containing trap sites, exposing compact vertically aligned crystalline domains with lower defectiveness and lower surface roughness, ultimately leading to enhanced carrier transport, facilitating interfacial charge extraction, and suppressing nonradiative recombination losses. Consequently, the PSCs fabricated with SP exhibit a higher power conversion efficiency (PCE) of 22.0% with a remarkable fill factor (FF) of 82%, surpassing the control device (20.5% PCE and 79% FF). Additionally, the SP-treated devices retain 94% of their initial efficiency after 40 days at 40% relative humidity, indicating improved shelf stability under moderately humid conditions.

Source: ACS Energy Letters

DOI: 10.1021/acsenergylett.6c01307