A new nonfullerene acceptor based on perylene diimides for organic solar cells

Abstract

Here we reported a nonfullerene electron acceptor based on perylene diimides, BP-PDI4, with a biphenyl core and four bulky PDI arms. BP-PDI4 showed a twisted 3D structure which successfully suppressed the large aggregation of perylene diimides in active layer. BP-PDI4 exhibited a wide optical band gap of 2.11 eV. Low-bandgap donor materials, namely PTB7-Th and PBDTTT-C-T, were chosen as donor materials for complementary absorption and well-matched energy levels. A PCE of 2.95% was achieved with Voc of 0.79 V, Jsc of 10.61 mA cm−2 and FF of 35.2%, when PTB7-Th was used as donor material.