Preparation of Bi2Te3/Nano-SiC Composite Thermoelectric Films by Electrodeposition

Abstract

Bi2Te3/nano-SiC composite thermoelectric films were prepared by electrodeposition in a nitric acid bath. The effects of SiC concentration and annealing treatment on the Seebeck coefficient and electrical resistivity of the films were investigated. The morphology, composition, and structure of the films were studied by scanning electron microscopy, x-ray fluorescence spectroscopy, and x-ray diffraction. The results showed that SiC nano-particles in electrodeposited Bi2Te3/nano-SiC composite films have readily apparent effects on the crystal orientation of the Bi2Te3 matrix and the morphology of the electrodeposited composite films. For nano-SiC particle concentrations <2 g/L the Seebeck coefficients of as-deposited films decrease with increasing nano-SiC particle concentration and decrease further after annealing treatment. Improvement in electrical conductivity compensated for the decrease in Seebeck coefficient and resulted in an enhanced power factor. Addition of nano-SiC particles to the composite films introduces more interfaces, which endows the composite films with lower electrical resistivity.