超高真空环境下有机分子表面化学反应的研究进展

超高真空（ultra-high vacuum,UHV）环境下的表面化学反应是构筑二维（two-dimensional,2D）功能纳米材料的重要方法,近年来,已经引起越来越多研究者的关注.本综述介绍了近几年来有机分子表面化学反应的几种主要类型,如有机金属配位反应、脱卤反应、脱氢环化、缩聚反应、炔烃偶合等,以及利用超高真空扫描隧道显微镜（STM）等测试手段对反应过程以及所形成的精细结构进行分析,特别是反应后结构中分子的连接方式,如有机金属配位键,C-C键,以及氢键等.     

Topological-Defect-Induced Superstructures on Graphite Surface

Topological defects in graphene induce structural and electronic modulations.Knowing exact nature of brokensymmetry states around the individual atomic defects of graphene is very important for understanding the electronic properties of this material.We investigate structural dependence on localized electronic states in the vicinity of topological defects on a highly oriented pyrolytic graphite(HOPG)surface,using scanning tunneling microscopy and spectroscopy.Several inherent topological defects on the HOPG surface and the local density of states surrounding them are explored,visualized as scattering wave-related(√3×√3)R30°superstructures and honeycomb superstructures.In addition,the superstructures observed near the grain boundary have a much higher decay length at specific sites than that reported previously,indicating far greater electron scattering on the quasi-periodic grain boundary.     

石墨烯纳米带的制备与电学特性调控

石墨烯由于其独特的晶体结构展现出了特殊的电学特性,其导带与价带相交于第一布里渊区的六个顶点处,形成带隙为零的半金属材料,具有优异的电子传输特性的同时也限制了其在电子学器件中的使用.因而科研人员尝试各种方法来打开其带隙并调控其能带特性,主要有利用缺陷、应力、掺杂、表面吸附、结构调控等手段.其中石墨烯纳米带由于量子边界效应和限制效应,存在带隙.本综述主要介绍了制备各类石墨烯纳米带的方法,并通过精确调控其细微结构,从而对其进行精确的能带调控,改变其电学特性,为其在电子学器件中的应用提供一些可行的方向.