Analysis of the anomalies in graphene thermal properties

A comprehensive analysis of the thermal conductivity of graphene under various conditions is presented in this study. Results obtained from different experimental and theoretical methods are analyzed and discussed for numerous conditions such as preparation process, shape, sample size, wavelength, and temperature. Wide discrepancies in the measured thermal conductivity results were found in many studies in the literature. Based on the cited data for the graphene thermal conductivity, the initially measured thermal conductivities appear to be highly overestimated. Majority of the documented results reported lower values of thermal conductivity than the earlier reported results. Furthermore, large differences in the values of the thermal conductivity of graphene were noticed from the cited results using different experimental and numerical methods (0.14 W/m K-20,000 W/m K). This raised an important question on the accuracy of these methods when measuring thermal conductivity of graphene at nanoscale. We have established the existence of a high degree of anomalies in the value of the thermal conductivity of grapheme. Therefore, proper experimental and theoretical studies should be conducted to accurately measure the thermal conductivity of graphene. (C) 2016 Elsevier Ltd. All rights reserved.