The direct bisaddition of methyl 5-azido-5-phenylpentanoate to C60 takes place in the two neighboring pentagon–hexagon junctions of the same five-membered ring, yielding a regioselective bisazfulleroid, namely bisimino-PCBM. Because of its open annulene structure, this new bisheterofullerene is not only considered to be an isoelectronic analogue of pristine C60, but also it is less symmetrical than previous reported mono-functionalized fullerenes, thereby displaying a stronger absorption in the visible region. The BHJ devices based on P3HT:bisimino-PCBM give a higher VOC of 0.77 V relative to those using the PCBM in the literature, which can be attributed to the combination of the nature of the nitrogen atom and the open bridged mode in a fullerene cage. Furthermore, the bisimino-PCBM consisting exclusively of a doubly bridged open 11-membered ring with a hydroacenaphthylene perimeter is very new, therefore there is still plenty of room to establish better efficiencies of BHJ photovoltaic cells.
5-azido-5-phenylpentanoate 甲基与 C60 的直接双加成反应发生在同一个五元环的两个相邻五角六角连接处,从而产生了一种具有区域选择性的双氮
富勒烯,即 bisimino-PCBM。由于其开放的环烯结构,这种新型双链
富勒烯不仅被认为是原始 C60 的等电子类似物,而且其对称性比以前报道的单官能化
富勒烯要差,因此在可见光区域显示出更强的吸收。与文献中使用 PCBM 的器件相比,基于 P3HT:bisimino-PCBM 的 BHJ 器件具有更高的 VOC(0.77 V),这可归因于氮原子的性质与
富勒烯笼中开放桥接模式的结合。此外,完全由具有氢
苊烯周边的双桥开放式 11 元环组成的双亚
氨基 PCBM 是一种非常新的材料,因此仍有很大的空间来提高 BHJ 光伏电池的效率。