ENHANCING THE FIGURE OF MERIT IN Zn4Sb3 FOR ITS USE IN HIGH TEMPERATURE AUTOMOTIVE APPLICATIONS

The Thermoelectric (TE) study is well known for the conversion of waste heat into electricity but the efficiency (ZT) obtained has been very low because of the interconnecting linkage between the physical parameters, Seebeck coefficient (S), electrical conductivity (σ) and thermal conductivity (κ) in bulk materials. However, recent results show that this difficulty has been overcome by the use nanostructured materials. New desirable properties are available at the nanoscale which is not found in conventional bulk materials. The most desirable properties to get high-efficiency (ZT>1) are large Seebeck coefficient, moderate electrical conductivity, and small thermal conductivity. The thermoelectric material Zn4Sb3 has been attracted for high temperature (ZT = 1.4 at 600 K) applications due to its outstanding thermoelectric properties, low cost and non-toxic. Only a limited number of efficient thermoelectric materials are known at this temperature. The efficient thermoelectric properties of Zn4Sb3 are due to Phonon-Glass Electron-crystal behaviour and the ability of the material to change its physical properties without affecting chemical and electronic properties. The aim of this review is to bring out the parameters and the methods to enhance the figure of Merit in Zn4Sb3 to enable its use in high temperature automotive applications.