Fig. 6. (a) Inverted structure PSCs, molecular structure of [BMIM]BF₄ and BCP and the J–V curves. Reproduced from ref. 213 with permission from the [Wiley-VCH], copyright [2018]. (b) Device structure of CsPbBrI₂ based PSCs, molecular structure of (NH₄)₂C₂O₄, and the J–V curves of devices with/without treatment. Reproduced from ref. 215 with permission from the [Elsevier], copyright [2020]. (c) Schematic diagram of PVCs, the chemical structures of PEACl, PEABr, PEAI, and the J–V curves of the device with/without treatment under CFL and LED irradiation. Reproduced from ref. 216 with permission from the [Elsevier], copyright [2020].