用于高分子太阳能电池的石墨烯量子点电极界面材料

Graphene quantum dot derivatives as anode/cathode interlayers for polymer solar cells

高分子太阳能电池中的电极界面层对于器件性能十分重要,开发新型电极界面材料是提高器件性能的有效方法.不同于传统的电极界面材料(导电高分子、无机氧化物、金属及其盐、高分子电解质等),我们发展了石墨烯量子点电极界面材料体系.与氧化石墨烯相比,边缘羧基化的石墨烯量子点(EC-GQD)的氧官能团种类单一,因此具有化学修饰可控、性质容易调节的特点,作为阳极/阴极界面材料能实现更高的器件性能.EC-GQD自身具有高功函、成膜性好的特点,作为阳极界面材料,器件性能优异;通过对EC-GQD边缘的羧基进行化学修饰,引入碱金属离子、季铵盐或极性基团,可实现电极功函的大幅度降低,因此我们开发出多种低功函的阴极界面材料.本文系统介绍了边缘羧基化石墨烯量子点衍生物的结构特征、化学修饰及其作为电极界面材料在高分子太阳能电池中的应用.

The interlayers play critical roles in polymer solar cells （PSCs）, and the development of novel interfacial materials is an efficient way to improve the device performance. We have developed graphene quantum dot （GQD） based interracial materials, which is different from the conventional interracial materials, such as semiconducting polymers, inorganic metal oxide, low work-function metals or salts, and polyelectrolytes. Compared with graphene oxide （GO）, the edge-carboxylated graphene quantum dots （EC-GQDs） contain single oxygen species of carboxyl groups （COOH）. EC-GQD based interfacial materials can improve the device performance of PSCs owing to their controllable chemical modification and tunable opto-electronic properties. EC-GQD itself can be used as anode interlayer to gain excellent device performance due to the high work-function and good film-forming property. Through chemical functionalization of EC-GQD from the COOH, the alkali metal cations, quaternary ammonium salts and other polar groups can be incorporated at the edge. The functionalized GQD can significantly decrease the work-function of electrodes, and thus can be used as the cathode interlayers for PSCs. In this review, we systemically introduced the unique structure of EC-GQDs, their chemical modification and the application of GQD-based interracial materials in PSCs.