Barrier Height Inhomogeneity in Mixed-Dimensional Graphene/Single CdSe Nanobelt Schottky Junctions

Mixed-dimensional graphene/single CdSe nanobelt (NB) Schottky junctions are fabricated, and the influence of Schottky barrier inhomogeneity on the electrical transport mechanism is investigated. The ideality factor increases and the zero-bias Schottky barrier height (SBH) decreases monotonically, as temperature decreases from 300 to 80 K. The temperature-dependent electrical transport characteristics can be explained by the SBH inhomogeneity. We use a spatial potential fluctuation model to analyze the conduction mechanism, where the SBH with a Gaussian distribution is assumed. The standard deviations of SBH distribution are up to 13.06% and 14.09% of the mean value of zero-bias SBH in 80-140 and 140-300 K, respectively, implying strong SBH inhomogeneity in typical graphene/CdSe NB junctions.