Measuring Electrical Properties of Layered Graphene with Kelvin Force Microscopy

摘要

In addition to exhibiting very promising compatibility with existing planar device architectures from an assembly point of view, single-layer graphene (SLG) and few-layer graphene (FLG) nanomaterials afford highly tunable electrical properties, such as carrier type or density, and rich electronic band structures. Potential applications of graphene sheets as ultrathin transistors, sensors, and other nano-electronic devices require they be supported on an insulating substrate. Therefore, a quantitative understanding of charge exchange at the interface as well as spatial distribution of charge carriers is critical for device design. Kelvin force microscopy (KFM), an atomic force microscopy (AFM)-based technique, now offers an experimental means to investigate the local electrical properties of both single-layer and few-layer graphene films on silicon dioxide. The effect of film thickness on surface potential can also be detected and quantitative measurements obtained.