Low-Bandgap Small Molecules as Non-Fullerene Electron Acceptors Composed of Benzothiadiazole and Diketopyrrolopyrrole for All Organic Solar Cells

Small molecules composed of benzothiadiazole and diketopyrrolopyrrole have affirmative optoelectronic properties as non-fullerene electron acceptors in photovoltaic device such as high crystallinity, decent electron mobility, a low bandgap, and proper molecular energy levels. The organic solar cell device combined with PTB7 as an electron donor exhibits a promising power conversion efficiency of 5.0%, demonstrating that the small molecules are promising electron acceptors for non-fullerene organic solar cells.