Nanostructure Engineering of ZnO Based Complex Oxides for Thermoelectric Application

In this review paper, the background and applications of thermoelectrics are first provided. The fundamentals of thermoelectrics which involve a few central physical parameters characterizing the electrical and thermal transport properties are described. The complicit among electrical and thermal conductivity as well as Seebeck coefficient in achieving large thermoelectric figure of merit is then discussed, which suggests nanostructure engineering as an effective approach to lower the lattice thermal conductivity for improved thermoelectric properties. The concept and approach are also demonstrated and discussed with selected examples. ZnO based thermoelectric materials are emphasized, due to the merits of inexpensiveness, earth abundance, chemical and high temperature stability as well as nontoxicity. A few examples of ZnO related oxide systems are briefly reviewed and proposed as useful model systems to investigate and understand the correlations between chemical compositions, phase equilibria, microstructure and thermoelectric properties. The outlook for designing and developing thermoelectric oxides with complex nanostructure is also provided at the end.