Fig. 4

a Schematic illustration of device architecture and cross-sectional SEM image of a PSC fabricated from the DMSO solution system. Reprinted with permission from [32], Copyright 2021, American Chemical Society. b UV—vis spectra of perovskite precursors in GVL and GBL. Reprinted with permission from [34], Copyright 2021, The Authors. Energy Technology published by Wiley-VCH GmbH c Solubility test of FAPbI₃ dissolved in EtOH, EtOH/DMA mixed solvent, and EtOH/DMA solution with PACl d FTIR spectra of the precursor solutions. Characteristic peaks between 1620 and 1635 cm^− 1 are assigned to the C = O stretching peaks of DMA. e Change of perovskite films with containing different types of RNH₃Cl. Reprinted with permission from [37], Copyright 2022, The Author(s), under exclusive license to Springer Nature Limited. f Schematic of perovskite crystal formation in 2-ME-CHP solution system. Reprinted with permission from [39], Copyright 2021, Elsevier. g SEM images of perovskite film change according to the amount of NMP additives. Reprinted with permission from [38], Copyright 2022, American Chemical Society