Journal Article nonfullerene acceptors organic solar cells solar cells KCTD9 protein, human Potassium Channels Research Support, Non-U.S. Gov't Ruddlesden-Popper perovskites charge transfer electrostatic potential flexible solar cells high miscibility intermolecular interactions layered perovskites light-emitting diodes molecular modification multiple quantum wells non‐radiative voltage losses organic photovoltaic cells organometal halide perovskites perovskites photovoltaics power conversion efficiency semitransparent small-molecular acceptors stability ternary organic solar cells tunable color two dimension voltage loss