Effect of grain size on thermal transport in post-annealed antimony telluride thin films

Abstract

The effects of grain size and strain on the temperature-dependent thermal transport of antimony telluride (Sb2Te3) thin films, controlled using post-annealing temperatures of 200 degrees C to 350 degrees C, were investigated using the 3-omega method. The measured total thermal conductivities of 400-nm-thick thin films annealed at temperatures of 200 degrees C, 250 degrees C, 300 degrees C, 320 degrees C, and 350 degrees C were determined to be 2.0 to 3.7 W/m.K in the 20 to 300 K temperature range. We found that the film grain size, rather than the strain, had the most prominent effect on the reduction of the total thermal conductivity. To confirm the effect of grain size on temperature-dependent thermal transport in the thin films, the experimental results were analyzed using a modified Callaway model approach.