Comparison of structural and electric properties of ZnO-based n-type thin films with different dopants for thermoelectric applications

Abstract

This paper presents a study on ZnO-based n-type thin films doped with Al, Ga, and Sn deposited on the glass substrates, using the solution derived by sol–gel reactions. The basic material properties associated with using the alternative chemical substances in synthesis process and different dopants to generate n-type conductivity in ZnO-based thin films which are transparent oxides, are investigated and discussed. Namely, the crystal structure and surface morphology of the obtained films were examined by means of XRD analysis and field-effect scanning electron microscope (FESEM). The electric properties of those films were characterized by Hall-effect measurements and temperature dependence of electrical conductivity, as well as Seebeck coefficients. The remarkable advantages corresponding to the certain characterization of each material composition were compared together. The aim is to fully understand the performance limitation of known materials and to set the scene for a suitable synthesis condition to get optimized materials for thermoelectric applications.