The anti-polar solvent technique is an effec- tive way to improve the film quality in a perovskite solar cell. In this work, we reveal the reason why chloroben- zene （CBZ） plays an important role in controlling the ...The anti-polar solvent technique is an effec- tive way to improve the film quality in a perovskite solar cell. In this work, we reveal the reason why chloroben- zene （CBZ） plays an important role in controlling the crystallization process. By investigating the formation of intermediate phases in the precursor solution, we observed that the CH3NH3I （MAI）-PbI2-dimethylformamide （DMF） or MAI-PbI2-dimethylsulphoxide （DMSO） adducts have not yet formed until washed with non-polar solvent. The accelerated formation of intermediate phase yields high crystalline perovskite layers. Rapid solvent evaporation and retarded perovskite crystallization in one-step method are efficient to obtain high-quality perovskite films. Conse- quently, MAI-PbI2-DMSO intermediate shows neat rod-like structure with high crystallinity, which eventually transforms extremely dense and uniform perovskite films.展开更多
基金supported by the National Basic Research Program of China (2016YFA0202400 and 2015CB932200)the National Natural Science Foundation of China (21403247)+2 种基金the External Cooperation Program of BIC, Distinguished Youth Foundation of Anhui Province (1708085J09)Chinese Academy of Sciences (GJHZ1607)STS project of Chinese Academy of Sciences (KFJ-SW-STS-152)
文摘The anti-polar solvent technique is an effec- tive way to improve the film quality in a perovskite solar cell. In this work, we reveal the reason why chloroben- zene （CBZ） plays an important role in controlling the crystallization process. By investigating the formation of intermediate phases in the precursor solution, we observed that the CH3NH3I （MAI）-PbI2-dimethylformamide （DMF） or MAI-PbI2-dimethylsulphoxide （DMSO） adducts have not yet formed until washed with non-polar solvent. The accelerated formation of intermediate phase yields high crystalline perovskite layers. Rapid solvent evaporation and retarded perovskite crystallization in one-step method are efficient to obtain high-quality perovskite films. Conse- quently, MAI-PbI2-DMSO intermediate shows neat rod-like structure with high crystallinity, which eventually transforms extremely dense and uniform perovskite films.
