Graphene功能分子在HOPG上自组装结构的密度泛函研究

DFT study of graphene functional molecule self-assembly on HOPG

Graphene自组装超分子结构,是指FTBC-Cn(n=4,6,8,12)分子有序自组装在高定向裂解石墨(HOPG)上形成的自组装超分子结构,是一种新型二维固体表面材料.其中FTBC-Cn分子是由三角形扶手椅型graphene每边添加2条含有n(n=4,6,8,12)个C原子的烷基链所形成具有曲面结构的一种分子.采用密度泛函理论及第一性原理方法,在不同温度(0 K,298K,333 K和353 K)下,模拟FTBC-Cn自组装超分子结构STM实验图像(即电子态密度分布):室温下,模拟结果与实验结果吻合较好,同时模拟预测了0 K,333 K和353 K下的STM图像.由此分析了其电子态密度分布在不同温度下的稳定性.结果表明将独立FTBC-Cn分子有序自组装在HOPG衬底上,设计出一种不同温度下微观构型和电子态密度分布稳定的自组装超分子结构.并且改变FTBC-Cn分子烷基链的长度,可以调节和控制自组装超分子的微观构型.

Hexafluorotribenzo[ a, g, m ] coronene with n-carbon alkyl chains [ FTBC-Cn （ n = 4, 6, 8 ） ] and their supramolecules self-assembly on highly oriented pyrolytic graphite （HOPG） surface are studied. It is a kind of new two-dimensional surface material namely graphene supramolecule self-assembly on HOPG. By the density functional theory （DFT）, STM experimental images （namely electronic density of state distribution） of graphene supramolecules have been simulated at room temperature. The simulated results of STM experimental images （namely electronic density of state distribution） are consistent with the experimental results well,and then the STM images of them at 0 K, 333 K, and 353 K are predicted, they keep stable with the change of temperature from 0 K to 353 K. It is indicated that after single FTBC-Cn molecules orderly self-assembly on HOPG substrate, a kind of two-dimensional surface material namely FTBC-Cn supramolecule self-assembly on HOPG with stable geometry and electronic density of state distribution are obtained, furthermore the geometry and electronic density of state distribution can be tuned and controlled by changing the length of alkyl chain.