Simultaneous measurement of thermal conductivity and interfacial thermal resistance of Sub-10 nm SWCNT bundle via Raman-probing of distinct energy transport states

Recent studies have shown that the thermal conductivity (κ) of single-walled carbon nanotubes (SWCNTs) can dramatically change due to structural changes within the same sample. This introduces substantial uncertainty to interfacial thermal resistance (ITR) measurement, which usually relies on pre-measured κ. Herein, we implement a novel transient Raman technique to distinguish and simultaneously measure the κ and ITR of a SWCNT bundle of less than 10 nm by employing multiple laser heating sizes, each carrying distinct information about the ITR and κ. The ITR is measured as 975–1200 K m W⁻¹ whereas κ is 180–246 W m⁻¹ K⁻¹. The ITR shows a decreasing trend against increased bundle size, demonstrating the impact of contact area in local energy transport. The measured κ is approximately 33 % of supported graphene reported in literatures. This significant κ reduction is attributed to the structural defects in the sample and the bundling effect consistent with earlier studies.