Isobutyramide Additive to Improve the Performance of CsPbBr3 Perovskite Solar Cells Prepared by Green Solvent.

The inorganic cesium lead bromide (CsPbBr3) perovskite solar cell (PSC) is considered as an attractive option for new solar cells due to its outstanding stability. Preparing CsPbBr3 PSCs with H2O can effectively save costs and reduce the harm of toxic solvents to the environment. However, the poor contact property of the PbBr2 layer to the CsBr/H2O solution and the ability of water to dissolve the CsPbBr3 phase has a significant impact on the performance of the CsPbBr3 devices. In this article, isobutyramide is introduced into the PbBr2 film in the first step to improve the wettability of the PbBr2 film to CsBr/H2O solution, followed by spin‐coating of the 150 mg mL−1 CsBr/H2O solution on the PbBr2 film. Using this strategy, the fabricated PSCs with the architecture of FTO/compact‐TiO2/mesoporous‐TiO2/CsPbBr3 film/carbon demonstrate outstanding performance with a maximum efficiency of 9.59%. Furthermore, after 45 days of storage at ambient temperatures, the unencapsulated device retains more than 96% of its original efficiency. Therefore, this work provides a good demonstration for the preparation of high‐efficiency and eco‐friendly CsPbBr3 PSCs. [ABSTRACT FROM AUTHOR]