Low band-gap weak donor–strong acceptor conjugated polymer for organic solar cell†
Abstract
By insertion of an additional weak acceptor into a donor–acceptor conjugated polymer backbone, a new weak donor–strong acceptor alternating copolymer PTTBOBT-DFBT was synthesized and it showed a low band-gap of 1.64 eV with a deep HOMO energy level (−5.44 eV). The bulk heterojunction (BHJ) solar cell fabricated from polymer PTTBOBT-DFBT displayed a remarkable power conversion efficiency (PCE) of 5.36% (Jsc = 11.04 mA cm−2, FF = 63.65%, Voc = 0.76 V).