Zhang Mingjia, Yu Jiaojiao, He Jianjiang, Huang Changshui
Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences , Qingdao 266101 , P.R. China.
Langmuir. 2019 Apr 23;35(16):5448-5454. doi: 10.1021/acs.langmuir.8b03953. Epub 2019 Apr 12.
Graphene modified by azo molecules has attracted much attention due to its promising graphene-enhanced Raman scattering (GERS) effect. Herein, we achieved the shortened distance between the dipole moment and graphene, by reducing the number of methylene groups and the chain length, and studied the Raman scattering in dipolar molecules/graphene hybrids. Whether for low or high concentrations, a more significant GERS signal can be observed, which can be attributed to the effective modulation of the dipole moment on interface energy level matching. Further, by fabricating FET devices, we demonstrate more obvious p-type and n-type doping in graphene that is affected by the chain length of the azobenzene molecule. On the basis of the dependence of the G band shift on the Fermi surface change, we further reveal the important role of dipole moment distance in dipolar molecules/graphene hybrids. These studies provide a new approach to optimize the interface matching between azobenzene and graphene and may help achieve more sensitive GERS detection.
偶氮分子修饰的石墨烯因其具有前景的石墨烯增强拉曼散射（GERS）效应而备受关注。在此，我们通过减少亚甲基数量和链长实现了偶极矩与石墨烯之间距离的缩短，并研究了偶极分子/石墨烯杂化物中的拉曼散射。无论是低浓度还是高浓度，都能观察到更显著的GERS信号，这可归因于偶极矩对界面能级匹配的有效调制。此外，通过制造场效应晶体管（FET）器件，我们证明了受偶氮苯分子链长影响的石墨烯中更明显的p型和n型掺杂。基于G带位移对费米面变化的依赖性，我们进一步揭示了偶极矩距离在偶极分子/石墨烯杂化物中的重要作用。这些研究为优化偶氮苯与石墨烯之间的界面匹配提供了一种新方法，并可能有助于实现更灵敏的GERS检测。
