Controlling Crystallization of Quasi‐2D Perovskite Solar Cells: Incorporating Bulky Conjugated Ligands

Quasi-2D hybrid halide perovskites have drawn considerable attention due to their improved stability and facile tunability compared 3D perovskites. The expansiveness of possibilities has thus far been limited by the difficulty in incorporating large ligands into thin-film devices. Here, a bulky bi-thiophene 2T ligand is focused on develop solvent system around creating strongly vertically-aligned (2T)2(MA)6Pb7I22 (n = 7) quasi-2D perovskite films. By starting with poorly coordinating (gamma-butyrolactone) adding small amount dimethylsulfoxide methanol, it found that vertical orientation z-uniformity greatly improved. These are carefully examined verified using grazing-incidence wide-angle X-ray scattering analysis advanced optical characterizations. films incorporated champion solar cells achieve power conversion efficiency 13.3%, short-circuit current density 18.9 mA cm-2, an open-circuit voltage 0.96 V, fill factor 73.8%. Furthermore, absorbing layers show excellent moisture, remaining unchanged after hundreds hours. In addition, more common butylammonium phenylethylammonium this heuristics deeper understanding how incorporate stable photovoltaic