Thermal conductivity measurement of oriented thin film with columnar nanostructures

Transforming thermoelectric materials into thin film forms with columnar nanostructures is an effective manipulation approach to reduce thermal conductivity and dramatically improve thermoelectric figure of merit from the theory basis. However, an ensuing problem is the difficulty of accurate obtaining of thermal conductivity of these thin films with columnar nanostructures, as conventional test means of thermophysical property is no longer applicable to this type of structures with porous surface and several microns thickness. This paper proposed using 3ω method to realize experimental characterization of the thermal conductivity of orientation Bi₂Te₃ thin film with columnar nanostructures and gave their thermal conductivity and thermal diffusivity values. This method can be used as experimental evaluation for thermal transport properties of microns thick thin films with columnar nanostructures.