Effect of 0.5% at.% indium addition on thermoelectric properties of Gallium doped-zinc oxide bulk #

Abstract

Thermoelectrics (TE) is well-known as a non-smoke technology for electricity production from waste heat and for greenhouse effect reduction. Enhancing power factor (PF = S² ᵟ, where is is Seebeck coefficient and ᵟ is electrical conductivity) and figure of merit of TE devices has attracted much scientific attention. Doping foreign elements into host bulk structure is a basic and traditional solution to modify the thermoelectric properties of materials. In this work, we use small amount of 0.5 at.% In as dopant which is incorporated into Ga-doped ZnO (GZO) bulk by using solid-state reaction method. The effects of In addition on electrical and thermoelectric characteristics of the GZO bulk are discussed in detail. As a result, the electrical conductivity of the In and Ga co-doped ZnO (IGZO) bulk increases more than 20 % as compared to the GZO bulk. The Seebeck coefficient decreases insignificantly, which leads to enhancing power factor by 55 % from 184.4 µW/mK² (GZO) to 285.2 µW/mK² (IGZO) at 500°C. The results open possibility to enhance the figure of merit of pure and doped ZnO material.