Progress and challenges: a review of ionic liquid treatment for efficient and stable perovskite solar cells

While perovskite solar cells (PSCs) have achieved remarkable power conversion efficiencies (PCEs) exceeding 26.1%, significant challenges remain in enhancing their efficiency and stability for commercial viability. Recently, the preparation of perovskite thin films based on solution methods has been widely studied. Most of the solvents used are organic solvents, which are highly toxic and therefore not conducive to large-scale production. However, the emergence of ionic liquids (ILs) with low toxicity and excellent properties will effectively solve this problem. In addition, many studies have shown that ILs play an active role in achieving efficient and stable PSCs. In this review, we focus on the recent advances in utilizing ILs as solvents, additives, and interface engineering within PSCs, and conclude with prospects for their future optimization and application in enhancing PSC performance. While perovskite solar cells (PSCs) have achieved remarkable power conversion efficiencies (PCEs) exceeding 26.1%, significant challenges remain in enhancing their efficiency and stability for commercial viability.