D-A-Ar-type small molecules with enlarged π-system of phenanthrene at terminal for high-performance solution processed organic solar cells

Two novel small molecules of TPA-DPP-P and TPA(DPP-P)2 with D-A-Ar framework were synthesized and characterized. Both D-A-Ar-type small molecules exhibited better photophysical and photovoltaic properties than the D-A-type counterpart of TPA-DPP. The highest PCE of 3.42% with a Voc of 0.78 V, Jsc of 9.24 mA/cm2 and FF of 48% was obtained in the optimized solution-processed TPA(DPP-P)2/PC71BM solar cell.155