A narrow band gap non-fullerene electron acceptor based on a dithieno-3,2-b:2′,3′-dlpyrrole unit for high performance organic solar cells with minimal highest occupied molecular orbital offset

Abstract

A new narrow band gap acceptor based on a dithieno-3,2-b:2',3'-dlpyrrole unit was synthesized. By blending a polymer PBTIBDTT with a small HOMO offset of 0.02 eV, the device gave a high PCE of 11.25% with a relatively high Voc of 0.83 V.