A matrix-confined molecular layer for perovskite photovoltaic modules.

Abstract

Metal halide perovskites with remarkable optoelectronic properties have become a competitive candidate for supporting the efficiency progression of photovoltaics. As the latest reported power conversion efficiency of research cells is comparable to that of commercialized silicon cells^1-3, the industrialization of perovskite solar cells is on the horizon^4,5. However, most high-efficiency inverted perovskite solar cells based on self-assembled molecules (SAMs) face challenges owing to the aggregation and hydrophobicity of the SAMs. Here we report a 'SAM-in-matrix' strategy to distribute partial SAMs into a stable matrix of tris(pentafluorophenyl)borane, which breaks the original molecular-stacking-induced aggregation. Two-dimensional lattice Monte Carlo simulations and experimental results reveal that this strategy forms efficient charge transport channels. SAM-in-matrix hole-transport-layer-based devices show universally higher efficiencies for various SAMs, with compact surface coverage, good conductivity and substantially fewer buried nanovoids. Moreover, this strategy shows prominent application potential for scalable production. A SAM-in-matrix hole transport layer on fluorine-doped tin oxide/NiO_x substrate facilitates the formation of large-area perovskite films with good crystalline quality and enhanced conductivity of NiO_x. A 1 m × 2 m large-area perovskite solar module is thus achieved with a certified efficiency of 20.05%.