NIR absorbing D–π–A–π–D structured diketopyrrolopyrrole–dithiafulvalene based small molecule for solution processed organic solar cells

A new low band gap small molecule with a D-π-A-π-D molecular structure composed of a dithiafulvalene (DTF) donor and a diketopyrrolopyrrole (DPP) acceptor was synthesized and tested for organic solar cells. Using the small molecule as an electron donor, and PC71BM as an acceptor a high power conversion efficiency (PCE) of 4.3% was achieved.