Multifunctional Conjugated Ligand Engineering for Stable and Efficient Perovskite Solar Cells

Surface passivation is an effective way to boost the efficiency and stability of perovskite solar cells (PSCs). However, a key challenge faced by most strategies reducing interface charge recombination without imposing energy barriers extraction. Here, novel multifunctional semiconducting organic ammonium cationic modifier inserted between light-harvesting film hole-transporting layer reported. It shown that conjugated cations can directly extract holes from efficiently, simultaneously reduce non-radiative recombination. Together with improved level alignment stabilized in device, triple-cation mixed-halide medium-bandgap PSC excellent power conversion 22.06% (improved 19.94%) suppressed ion migration halide phase segregation, which lead long-term operational stability, demonstrated. This strategy provides new practical method engineering PSCs toward stability.