D-A-D structured organic molecules with diketopyrrolopyrrole acceptor unit for solution-processed organic solar cells

Abstract

Four solution-processable D-A-D structured organic molecules with diketopyrrolopyrrole (DPP) as acceptor unit and triphenylamine (TPA) or (4-hexyl) thieno [3,2-b]thiophene (HTT) as donor unit, DPP8- TPA, DPP8-TPA-OR, DPP6-HTT and DPP8-HTT, were designed and synthesized for the application as donor materials in solution-processed organic solar cells (OSCs). The molecules show broad absorption and relatively lower highest occupied molecular orbital energy levels. Photovoltaic properties of the molecules were investigated by fabricating the bulkheterojunction OSCs with the molecules as donor and PC 71BM as acceptor. Power conversion efficiency of the OSC based on DPP8-HTT reached 1.5% under the illumination of AM1.5, 100mWcm-2. © 2014 The Author(s) Published by the Royal Society.