Poly(carbazole phosphonic acid) as a versatile hole-transporting material for p-i-n perovskite solar cells and modules

Commonly used poly(triaryl amine) and carbazole phosphonic acid (PACz) hole-transporting materials (HTMs) typically suffer from poor wettability for perovskite solutions and sensitiveness to layer thickness/substrate roughness, respectively, thus limiting their applications in the real-world manufacturing of perovskite modules. To address these issues, in this work, we report a new type of HTM by polymerizing PACz into a versatile polymeric material. The resultant polymeric HTM (named Poly-4PACz) exhibits excellent hole-extraction capacity and can further suppress the interfacial recombination and stabilize perovskite/HTM interfaces. Most importantly, Poly-4PACz exhibits high conductance and is insensitive to layer thickness on both indium-doped tin oxide and fluorine-doped tin oxide substrates, which are highly desirable for the scalable coating of perovskite films. As a result, the blade-coated p-i-n perovskite solar cells and modules realize impressive power conversion efficiencies of 24.4% and 20.7% at 6.84 mm2 and 25.0 cm2 aperture areas, respectively.