高定向热解石墨表面局域导电增强现象的扫描探针显微学研究

基于导电型原子力显微镜和扫描隧道显微镜的对比观察，研究高定向热解石墨表面上残留石墨片的导电增强现象.根据样品电阻的测量数据，将这种现象归结为导电针尖与石墨表面的点接触问题，并且发现接触电导和接触点处局域的电子密度成正比，从而确定石墨表面的局域导电增强现象的原因在于残留在石墨表面的石墨片具有较高的电子密度.关键词：扫描隧道显微镜导电原子力显微镜高定向热解石墨导电性

Conductance enhancement phenomenon of graphene ribbons on highly oriented pyrolytic graphite surfaces studied by scanning probe microscopy

Based on comparative observations with the conducting atomic force microscope and the scanning tunneling microscope，conductance enhancement phenomenon of graphene ribbons on highly oriented pyrolytic graphite surfaces has been studied. According to measured data of local resistance on the samples，the phenomenon is attributed to the state of point contact of the conducting tip on the sample surface. It was demonstrated that the conductance of the point contact is proportional to the local density of electrons in the contacting surface area，so we conclude that the conductance enhancement phenomenon results from the high density of electrons on the graphene ribbons.