T−n (n: 2.4∼2.56) temperature dependence of thermal resistance at single-walled carbon nanotubes/SiO2 interface at

Abstract

The burgeoning significance of energy coupling at interfaces of nm dimension aligns seamlessly with the rapid strides made in micro/nanoelectronics. The nm-scale interface thermal resistance (ITR) is strongly affected by temperature but is poorly understood to date due to extreme challenges in nm-scale characterization. This work reports a pioneering and high-level study on how temperature affects the ITR of single-walled carbon nanotube (SWCNT)-SiO2 interface with a < 8 nm lateral dimension. From 297 to 77 K, the ITR is observed to increase from 530 to 725 to (1.56–1.74)×104 K·m·W−1. The reported ITRs at room temperature are in line with reported data for SWCNT/SiO2 interface. The ITR variation with temperature is compared with the prediction based on the phonon diffuse mismatch model (DMM). A great qualitative agreement is observed while the DMM under the Debye approximation of linear dispersion underestimates the ITR. Our ITR dependency on temperature takes the form of T−n where n is found to be 2.4 and 2.56 for two different locations of the sample. Such observation resembles the dependency of specific heat on temperature far below the Debye temperature. We introduce a concept termed as the effective interface energy transmission velocity (vi,eff) in an attempt to rule out the role of specific heat in ITR-temperature dependence to uncover the intrinsic effect of temperature on interface energy coupling. Very interestingly, vi,eff shows little variation over a wide temperature range for various reported interfaces. Further exploration and refinement of this concept is expected in forthcoming research endeavors.