“…On the other hand, inverted perovskite thin-film solar cells have been successfully integrated with silicon solar cells to form two-terminal tandem solar cells, resulting in a high PCE of 29.8% [21]. In inverted perovskite solar cells, the most widely used HTLs are conductive PEDOT:PSS polymer films [22][23][24][25], NiO x inorganic films [26][27][28][29], CuO x inorganic films [30][31][32], WO x inorganic films [33][34][35], poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) (PTAA) polymer films [36][37][38][39], poly(3-(4-carboxybutyl)thiophene-2,5-diyl)-X (P3CT-X) polymer films (X: Na, K, Rb and Cs) [40][41][42][43] and p-type self-assembled monolayers (SAMs) [44][45][46][47]. Among these HTLs, P3CT-X and p-type SAM ultra-thin layers are also used as a hole modification layer (HML) to modify the surface work function of transparent anode electrodes (TCEs) [48,49].…”