| 摘要： |
It has been proven that the introduction of F atom and the replacement of alkyl side-chain with alkylthio substituent could be the effective side-chain strategies, to obtain the deep highest occupied molecular orbital (HOMO) energy level with little influence on the optical absorption, and in turn, the small photo energy loss (E-loss). In this work, we combine the advantages of D-A(pi)-Q-A(pi) strategy and the above side chain engineering, to construct a series of high-performance polymers P1-P3 with high open-circuit voltage (V-OC) of exceeding 0.90 V in the conventional solar cells. Meanwhile, small E(loss)s of 0.73-0.78 eV are achieved accompanying high V-OC and almost unchanged optical bandgaps of similar to 1.70 eV, which are the smaller values in comparison with that of the other high-performance polymer systems. More encouragingly, P2-based solar cells exhibit high PCE of 10.30% and V-OC of 0.97 V, which is one of the highest values for polymer/fullerene based solar cells. Our work not only demonstrates a series of high-efficiency new materials, but also strongly confirms that the combination of D-A(pi)-Q-A(pi) arrangement and rational side chain engineering is a very promising strategy to construct high-performance photovoltaic polymers with reduced energy loss. |
