Thermal boundary resistance from transient nanocalorimetry: A multiscale modeling approach

Abstract

The Thermal Boundary Resistance at the interface between a nanosized Al film and an Al2O3 substrate is investigated at an atomistic level. A room temperature value of 1.4 m 2 K/GW is found. The thermal dynamics occurring in time-resolved thermo-reflectance experiments is then modelled via macro-physics equations upon insertion of the materials parameters obtained from atomistic simulations. Electrons and phonons non-equilibrium and spatio-temporal temperatures inhomogeneities are found to persist up to the nanosecond time scale. These results question the validity of the commonly adopted lumped thermal capacitance model in interpreting transient nanocalorimetry experiments. The strategy adopted in the literature to extract the Thermal Boundary Resistance from transient reflectivity traces is revised at the light of the present findings. The results are of relevance beyond the specific system, the physical picture being general and readily extendable to other heterojunctions.

Ultrafast Thermo-Optical Dynamics of a Single Metal Nano-Object

“…This results in an exponential decay of ∆Tp with a characteristic time τ=cAuh/G, cAu being the volumetric heat capacity of gold and G the Kapitza thermal conductance of the nanostructure/substrate interface. 51 Such an exponential decay, with a characteristic time linearly scaling with ND height, has been experimentally reported for permalloy NDs nanopatterned on a Si substrate 10 and the transient thermal dynamics theoretically investigated for the case of Cu NDs deposited on Si 52 . Within the context of the present study, the τ1∝h scaling is in approximate agreement with the 2.4x smaller τ1 values determined for h=18 nm NDs as compared to h=40 nm ones, and their weak dependence on ND diameter.…”

Optical wavelength dependence of photoacoustic signal of gold nanofluid

“…Another aspect, which needs to be accounted for, is the thermal boundary conductance (TBC), also addressed as Kapitza's conductance, ruling the heat transfer at the interface between the NPs and the liquid. The estimation of TBC is still a debated issue, since the latter strongly depends on the involved materials combination [37] , [38] , on temperature [39] , [40] , and on the sample preparation technique [41] .…”

Thermal conductance across harmonic-matched epitaxial Al-sapphire heterointerfaces

“…To explain the experimental results, theories of interfacial thermal conductance have been developed since the 1950s, such as the acoustic mismatch model (AMM) and the diffuse mismatch model (DMM) 4,5,26 . More recently, other theoretical tools were used to calculate TBC, for instance, equilibrium/non-equilibrium molecular dynamics (MD) 27,28 , interface conductance modal analysis (ICMA) 29 , wave packet method 30 , atomistic Green's function (AGF) 31,32 , and non-equilibrium Landauer approach 33 . Due to the complicated nature of interfaces, most of the theoretical calculations cannot capture the detailed features of the interface.…”