A green ionic liquid solvent for additive-free, efficient and stable bladed perovskite solar cells under ambient conditions.

Although the preparation of large-area perovskite films using blade-coating technology has made rapid progress in recent years, the instability of precursor solutions and the harmful and toxic solvents limit the preparation of bladed perovskite films in ambient air. In addition, additives are usually indispensable for the preparation of high-quality bladed perovskite films. Here, we introduce the ionic liquid methylammonium acetate (MAAc) instead of N,N-dimethylformamide and dimethyl sulfoxide as a solvent to fabricate perovskite solar cells (PSCs) using the blade-coating method. Using MAAc as a solvent solves the toxic and harmful problems of traditional solvents and realizes the preparation process of bladed perovskite films in ambient air. Surprisingly, the power conversion efficiency of the bladed PSCs prepared under ambient conditions exceeds 14% without additives. Moreover, the unencapsulated device exhibits excellent storage stability in ambient air. This work provides a method for preparing highly efficient and stable perovskite optoelectronic devices using a blade-coating method in ambient air without additives. [ABSTRACT FROM AUTHOR]