Paper NS+SE-MoM10
Enhanced Thermal Transport at Covalently Functionalized Carbon Nanotube Array Interfaces to Oxide-forming and Noble Metals

Monday, November 10, 2014, 11:20 am, Room 304

It has been more than a decade since the experimental demonstration that the thermal conductivity of carbon nanotubes can exceed that of diamond, which has the highest thermal conductivity among naturally existing materials. In spite of tremendous promise as a thermal material, results have been disappointing for practical thermal systems and applications based on nanotubes. The main culprit for the dramatic shortfall in the performance of nanotubes in practical systems is high thermal interface resistance between them and other components due to weak adhesion at the interface. We demonstrated a six-fold reduction in the thermal interface resistance between both oxide-forming and noble metal surfaces and vertically aligned multi-wall carbon nanotube arrays after bridging the interface with short, covalently-bonded organic molecules. Increased thermal transport was associated with a significant increase in interface mechanical adhesion [1]. Functionalized CNT thermal interfaces were shown to be stable in air for many months and resistant to thermal stress up to 180° C. We were also able to independently determine the intrinsic CNT interface resistance and the fraction of the CNT array contributing to thermal transport by preforming multi-frequency time-domain thermo-reflectance (TDTR) measurements. Since our interface-functionalization method avoids destructive solution-phase processing, this development may lead to the practical integration of CNT arrays for thermal management in microelectronic devices

[1] "Enhanced thermal transport at covalently functionalized carbon nanotube array interfaces", Sumanjeet Kaur, Nachiket Raravikar, Brett A. Helms, Ravi Prasher & D. Frank Ogletree, Nature Communications 5 3082 (2014) doi: 10.1038/ncomms4082