Thermal conductivity of thermoelectric thick films prepared by electrodeposition

Abstract

Because of a lack of appropriate methods and the difficulties of sample preparation, few direct measurements of the thermal conductivity of thermoelectric materials in thin films have been reported. We prepared thermoelectric thin films of four types containing Bi–Te and Sb–Te by electrodeposition from aqueous solutions with and without added surfactant, and evaluated their intrinsic thermal conductivity with a modified parallel-strip technique. Three thermoelectric materials showed values 0.2–0.5 W m−1 K−1 of intrinsic thermal conductivity; for the other type problems of sample preparation precluded measurement. According to observations with a scanning electron microscope, the existence of grain boundaries in the thermoelectric thin films is likely the cause of the small values, and their fragile structure causes difficulty in preparation of a test sample.