Effect of resonant impurities on electrical resistivity in polycrystalline graphene

We show that the asymmetry in the behavior of the electrical resistivity of polycrystalline graphene sheet, discovered in a number of experiments, can be explained by the presence of resonant impurities in the samples. Noticeable asymmetry is already evident at very low impurity concentrations (less than 0.1%). The characteristic behavior of the resistivity curves is found to depend on both the grain boundary structure and the concentration and type of impurity. We found a very high sensitivity of the resistivity even to small changes in the concentration of the resonant impurities. The results obtained are of interest both for the characterization of polycrystalline samples and for a variety of practical applications in graphene-based nanoelectronics.