Effect of electronic contribution on temperature-dependent thermal transport of antimony telluride thin film

Abstract

We study the theoretical and experimental characteristics of thermal transport of 100nm and 500nm-thick antimony telluride (Sb2Te3) thin films prepared by radio frequency magnetron sputtering. The thermal conductivity was measured at temperatures ranging from 20 to 300K, using four-point-probe 3-ω method. Out-of-plane thermal conductivity of the Sb2Te3 thin film was much lesser in comparison to the bulk material in the entire temperature range, confirming that the phonon- and electron-boundary scattering are enhanced in thin films. Moreover, we found that the contribution of the electronic thermal conductivity (κe) in total thermal conductivity (κ) linearly increased up to ∼77% at 300K with increasing temperature. We theoretically analyze and explain the high contribution of electronic component of thermal conductivity towards the total thermal conductivity of the film by a modified Callaway model. Further, we find the theoretical model predictions to correspond well with the experimental results.