基于苯并噻二唑的D-A-D型有机小分子光伏材料的合成及其性能研究

Synthesis and Properties of the D-A-D Type Photovoltaic Organic Small Molecules with Benzothiadiazole Unit

合成、表征了三种基于苯并噻二唑的D-A-D型有机小分子光伏材料C1-C3.该类小分子以苯并噻二唑为受体中心单元,以芴、三苯胺、咔唑为给体末端单元.C1-C3具有优异的热稳定性能,其热分解温度（Td）都大于290℃,且在300-650nm表现明显的光谱吸收.以该类小分子为给体材料掺杂富勒烯衍生物（PC60BM）受体材料制作溶液加工本体异质结光伏器件,其中C1表现出最好的光伏性能（PCE=1.39%,Jsc=6.18mA/cm^2,Voc=0.74V,FF=0.30）.该研究表明末端给体单元对基于苯并二唑D-A-D型有机小分子的光伏性能具有显著影响,合理选择末端给体单元有望获得高转换效率的有机小分子光伏材料.

Three novel D-A-D type small molecules（SMs）were synthesized and characterized using benzothiadiazole as accepter core,and fluorene（or triphenyl-amine or carbazole）as donor terminal group,respectively.All these SMs showed excellent thermal stability with a thermal decomposition temperature over 290 ℃ at 5% weight loss and distinct UV-vis absorption bands in 300-650nm.In contrast to C2 and C3,C1 exhibited better photovoltaic performance in the solution-processable solar cells with the maximum power conversion efficiency of 1.39%（Jsc=6.18mA/cm^2,Voc=0.74 V,FF =0.30）.This work further demonstrates that tuning the terminal donor group can significantly influence the photovoltaic performance of its resulting SMs.