苯并三氮唑基窄带隙聚合物受体用于高效全聚合物太阳电池

A new low-bandgap polymer acceptor based on benzotriazole for efficient all-polymer solar cells

合理设计具有强和宽吸收的聚合物受体有助于提高光伏性能。本文以七环苯并三氮唑(Y9-C16)为构筑单元,噻吩为连接单元合成一个新型聚合物受体材料PY9-T。该受体材料的薄膜具有较低的带隙(1.37 eV)和较高的消光系数(1.44×10^(5) cm^(−1))。当PY9-T与宽带隙聚合物给体PBDB-T共混时,制备全聚合物太阳电池(APSC)实现10.45%的高能量转换效率,器件具有0.881 V的高开路电压和19.82 mA/cm^(2)的高短路电流密度。此外,器件在100°C退火后,共混膜形貌仅发生微小的变化,表明APSC具有好的热稳定性,Y9-C16为开发高效稳定的聚合物受体提供了新的构筑单元。

The rational design of polymer acceptors with strong and broad absorption is critical to improve photovoltaic performance.In this work,a new polymer acceptor PY9-T based on heptacyclic benzotriazole(Y9-C16)as a building block and thiophene unit as the linking unit was synthesized,which exhibited a low bandgap(1.37 eV)and a high extinction coefficient of the neat film(1.44×10^(5) cm^(−1)).When PY9-T was blended with the wide bandgap polymer donor PBDB-T,the all-polymer solar cells(APSCs)showed a high power conversion efficiency(PCE)of 10.45%with both high open circuit voltage of 0.881 V and short-circuit current density of 19.82 mA/cm^(2).In addition,APSCs based on PY9-T show good thermal stability,as evidenced by slight changes morphologies when annealed at 100℃.These results suggest that Y9-C16 provides a new building block to develop efficient and stable polymer acceptors.