Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Layer-dependent nanoscale electrical properties of graphene studied by conductive scanning probe microscopy | Zhao et al. Nanoscale Research Letters 2011 6 498 http content 6 1 498 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Layer-dependent nanoscale electrical properties of graphene studied by conductive scanning probe microscopy Shihua Zhao Yi Lv and Xinju Yang Abstract The nanoscale electrical properties of single-layer graphene SLG bilayer graphene BLG and multilayer graphene MLG are studied by scanning capacitance microscopy SCM and electrostatic force microscopy EFM . The quantum capacitance of graphene deduced from SCM results is found to increase with the layer number n at the sample bias of 0 V but decreases with n at -3 V. Furthermore the quantum capacitance increases very rapidly with the gate voltage for SLG but this increase is much slowed down when n becomes greater. On the other hand the magnitude of the EFM phase shift with respect to the SiO2 substrate increases with n at the sample bias of 2 V but decreases with n at -2 V. The difference in both quantum capacitance and EFM phase shift is significant between SLG and BLG but becomes much weaker between MLGs with a different n. The layer-dependent quantum capacitance behaviors of graphene could be attributed to their layer-dependent electronic structure as well as the layer-varied dependence on gate voltage while the layer-dependent EFM phase shift is caused by not only the layer-dependent surface potential but also the layer-dependent capacitance derivation. Keywords graphene scanning capacitance microscopy electrostatic force microscopy layer dependence quantum capacitance Graphene is drawing an increasing interest nowadays since its debut in reality 1 as it is a promising material for future nanoelectronic applications 2-4 . While many transport property studies have been carried out by traditional techniques with nanoelectrodes fabricated on graphene 5-8 conductive scanning probe microscopy has recently been applied for direct nanoscale electrical