to 3.72% for P(BDT-T-BT) and to 4.93% for P(BDT-TT-BT). Compared to furan and thiophene, thieno[3,2-b]thiophene π-bridge in the copolymers shows superior photovoltaic performance. The results indicate that the photovoltaic performance of some high efficiency D–A copolymers reported in literatures could be improved further by inserting suitable π-bridges.
基于苯并二
噻吩(BDT )的一系列共轭施主(D)-π-受体(A)共聚物P(BDT-F-BT),P(BDT-T-BT)和P(BDT-
TT-BT)通过
钯催化的斯蒂勒偶联法设计合成了供体单元和具有不同π桥的苯并
噻二唑(BT)受体单元。所述BDT供体单元和受体BT单元之间的π-桥是
呋喃(˚F)在P(BDT-F-BT),
噻吩(Ť中)P(BDT-T-BT)和
噻吩并[3,2- b ]
噻吩(
TT)在P(BDT-
TT-BT)。已经发现,π-桥显着影响共聚物的分子结构和光电性能。随着
呋喃到
噻吩,然后到
噻吩并[3,2- b ]
噻吩的π桥变化,分子链的形状逐渐从z形变为几乎直线。的带隙P(BDT-F-BT),P(BDT-T-BT)和P(BDT-
TT-BT),从1.96至1.82调谐到1.78电子伏特与HOMO能级向上移从-5.44到-5.35至-5.21 eV。以聚合物为施主和PC 71 BM为受体的块状异质结太