Evaluation of thermal conductivity of a multi-walled carbon nanotube using the ΔV_gs method

Thermal conductivity of a multi-walled carbon nanotube (MWNT) was evaluated using the ΔV_gs method for the first time. MWNTs were prepared in pillars, and the pillars were placed on two aluminum nitride (AlN) substrates. An AlGaN/GaN high electron mobility transistor (HEMT) chip, which was set on an AlN substrate, was used as a thermometer and as a thermal source. The thermal resistance of the sample was measured using the ΔV _gs method. From the thermal resistance of MWNT pillars, we succeeded in evaluating the thermal conductivity of a MWNT pillar and that of a MWNT as high as 74.2 and 950W/(m·K), respectively. The thermal conductivity of MWNTs evaluated in this study is much higher than that of usual metals. We confirmed that MWNTs are promising materials for heat dissipation problems.