小分子给体桥联单元烷基链取代位置对光伏器件性能的影响

Effect of Substitution Positions of Alkyl Chains in Small MolecularDonor Bridged Units on the Performance of Photovoltaic Devices

设计合成了2个同分异构体小分子给体C2-C-F和C2-M-F,二者仅中间桥联三噻吩单元上烷基链的取代位置不同.研究结果表明,烷基链取代位置对其吸光性能和能级影响较小,但对与受体BTP-4F-12共混后的活性层形貌具有较大影响.其中,小分子给体C2-C-F与受体BTP-4F-12共混的薄膜获得了较好的形貌,光伏器件效率达到12.84%.研究结果表明,可以通过烷基取代的位置来精细调控活性层的形貌,为高效小分子给体的设计提供了有益的参考.

Two isomeric small molecule donors,C2-C-F and C2-M-F,with only the different substitution positions of the alkyl chains on the intermediate bridged trithiophene units,were designed and synthesized.It was found that the alkyl chain substitution position has little effect on their absorptions and energy levels,but has a significant impact on the morphology of the active layers when blended with the acceptor BTP-4F-12.Better morphology was obtained for the active layer based on small molecule donor C2-C-F,and an efficiency of 12.84%was achieved for the C2-C-F-based photovoltaic device.This result indicates that the morphology of the active layer can be finely regulated through the alkyl substitution positions,providing a useful avenue for the design of efficient small molecule donors.