Complex Thermoelectric Materials

The widespread use of thermoelectric generators has been limited by the low material efficiency of the thermoelectric material. Complex electronic band structures provide mechanisms to achieve high zT in thermoelectric materials through band structure engineering. Complex crystal structures that enable relatively low thermal conductivity have lead to several new classes of thermoelectric materials. Fast diffusing or ‘liquid-like’ elements in the complex materials Zn4Sb3 and Cu2Se provide additional mechanisms to scatter and otherwise inhibit phonon heat conductivity. The principles of Zintl chemistry facilitates the search for new complex materials and the tuning of known thermoelectric materials with earth abundant, non-toxic elements. The synthesis of nanoscale composites can be controlled with the aid of equilibrium phase diagrams to produce microstructure of varying composition and length scale. Controlled Vocabulary Terms band structure; thermal conductivity; thermoelectricity