文摘
A novel electron-withdrawing group 5-(2,6-dimethyl-4H-pyran-4-ylidene)-1,3-diethyl-2-thioxo-dihydropyrimidine-4,6(1H,5H)-dione (PD) was designed and synthesized according to Knoevenagel condensation. On this basis, a small molecule 8TPDC8 with oligothiophene as electron-donating unit and PD as electron-accepting unit was designed and synthesized. UV-vis absorption spectrum displayed that 8TPDC8 possesses a relatively broad absorption range (from 300 to 900 nm). The cyclic voltammetry investigation displayed that the highest occupied molecular orbital (HOMO) energy level of 8TPDC8 was ?.28 eV, which promised good air stability and high open circuit voltage (Voc) for photovoltaic application. The bulk heterojunction (BHJ) photovoltaic devices were fabricated with 8TPDC8 as the donor material and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) as the acceptor material. A power conversion efficiency of 1.28 % has been obtained under the illumination of AM 1.5, 100 mW/cm2.