Temperature dependent thermal conductivity of a free-standing graphene nanoribbon

This letter reports on the measurements of the thermal conductivity along a long free-standing graphene nanoribbon (GNR) by a one-dimensional steady-state method. The GNR was cut from a single layer graphene sheet and it has the length and width of 508 and 385 μm, respectively. It is observed from the measurements that the GNR has highly temperature dependent thermal conductivities. The values increase from 126.21 W·m−1·K−1 to 877.32 W·m−1·K−1 in the temperature range from −75 to 100 °C, with an exception of an abruptly large value of 1044.41 W·m−1·K−1 at 50 °C. The electrical resistances of the GNR decrease linearly with the temperature and the absolute resistance-temperature coefficient was determined to be a pretty large value of 0.004148 K−1, indicating obvious temperature dependent electrical conductive behavior.