A homopolymer based on double B ⟵ N bridged bipyridine as electron acceptor for all-polymer solar cells

Abstract

Polymer electron acceptors for all-polymer solar cells (all-PSCs) are usually conjugated copolymers, which contain alternating electron-rich units and electron-deficient units. In this manuscript, we report a conjugated homopolymer (P-BNBP) based on an electron-deficient unit of double B⟵N bridged bipyridine, which can be used as electron acceptor for all-polymer solar cells. P-BNBP shows low-lying LUMO energy level of −3.59eV, high absorption coefficient of 1.6×105Lmol−1cm−1 at 626nm and moderate electron mobility of 4.37×10−6cm2V−1s−1. All-PSC devices exhibit power conversion efficiencies of 2.44%–3.04%. These results demonstrate that conjugated homopolymers are promising as electron acceptor materials for all-PSCs.