Thermal Conductivity of CVD grown graphene

When suspended, CVD grown graphene has a high thermal conductivity (k) of 2,500$\pm $1100 W/mK near 350 K. But for practical applications, graphene would be attached to a substrate. Previously it was reported that the CVD grown graphene supported on Si/SiO2 has a k value as low as 370+650/-320 W/mK in ambient. We find that the k of CVD grown graphene on glass varies in a range of 1100 - 2000 W/mK and depends on the growth parameters. The k of graphene is measured by a differential thermocouple technique and compared with that obtained by scanning thermal microscopy. Moreover, the samples grown in ambient pressure have shown higher k compared to the graphene grown at low pressure.