Exfoliating and Dispersing Few-Layered Graphene in Low-Boiling-Point Organic Solvents towards Solution-Processed Optoelectronic Device Applications

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• 作者：Dr. Lu Zhang ; Zhongshuo Miao ; Zhen Hao and Prof. Jun Liu
• 刊名：Chemistry – An Asian Journal
• 出版年：2016
• 出版时间：May 6, 2016
• 年：2016
• 卷：11
• 期：9
• 页码：1441-1446
• 全文大小：1498K
• ISSN：1861-471X

文摘

With normal organic surfactants, graphene can only be dispersed in water and cannot be dispersed in low-boiling-point organic solvents, which hampers its application in solution-processed organic optoelectronic devices. Herein, we report the exfoliation of graphite into graphene in low-boiling-point organic solvents, for example, methanol and acetone, by using edge-carboxylated graphene quantum dots (ECGQD) as the surfactant. The great capability of ECGQD for graphene dispersion is due to its ultralarge π-conjugated unit that allows tight adhesion on the graphene surface through strong π–π interactions, its edge-carboxylated structure that diminishes the steric effects of the oxygen-containing functional groups on the basal plane of ECGQD, and its abundance of carboxylic acid groups for solubility. The graphene dispersion in methanol enables the application of graphene:ECGQD as a cathode interlayer in polymer solar cells (PSCs). Moreover, the PSC device performance of graphene:ECGQD is better than that of Ca, the state-of-the-art cathode interlayer material.