fig1

Figure 1. (A) Schematic overview of representative deposition techniques used for perovskite film fabrication, including spin-coating, pressure-assisted crystallization, inkjet printing, blade coating, slot-die coating, spray coating, and thermal evaporation; (B) Illustration of a fully roll-to-roll (R2R) printing process for flexible perovskite solar cells and the corresponding device structure; (C) Summary of the energy-level alignment of representative ETLs, perovskite absorbers, and HTLs commonly used in perovskite solar cells. TCO: Transparent conductive oxide; IML: interfacial modification layer; HTL: hole-transport layer; ETL: electron-transport layer; FTO: fluorine-doped tin oxide; ITO: indium tin oxide; PCDTBT: poly[N-9’-heptadecanyl-2,7-carbazole-alt-5,5-(4’,7’-di-2-thienyl-2’,1’,3’-benzothiadiazole)]; PTAA: poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; P₃HT: poly(3-hexylthiophene); Spiro-OMeTAD: 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene; PVB-DAAF: polystyrene-functionalized 9,9-diarylfluorene-based triaryldiamine; PEDOT:PSS: poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate).