Аннотация
Ionic liquids (ILs) have emerged as a promising class of additive for modulating perovskite crystallization behavior and thin film morphology. However, the influence of incorporating ILs directly within the cesium lead iodide bromide (CsPbI2Br) perovskite precursor system is less explored. This work aims to investigate the impact of using various IL additives in the bulk of the CsPbI2Br perovskite material and how it affects thin film formation. We study the morphology of CsPbI2Br when incorporated with five different ILs based on the common 1-ethyl-3-methylimidazolium [EMIM]+cation, but varying the anion: bis(pentafluoroethylsulfonyl)imide ([EMIM]+[PFSI]−), bis(trifluoromethylsulfonyl)imide ([EMIM]+[TFSI]−), diethyl phosphate ([EMIM]+[DEP]−), dimethyl phosphate ([EMIM]+[DMP]−), and hexafluorophosphate ([EMIM]+[PF6]−). Through characterization of the perovskite films, we found that the morphology of CsPbI2Br is largely different depending on the choice of IL used. These morphological changes provide insights into how different IL-perovskite interactions affect crystallization and thus thin film quality. The experimental results help in understanding of IL-mediated crystallization, facilitating the development of additive engineering for high-performance perovskite solar cells (PSCs).