Abstract
In order to develop a high-performance thermoelectric material, it is of great importance to find the way to control three thermoelectric properties: Seebeck coefficient S, electrical conductivity σ, and thermal conductivity κ. Our recent studies revealed that Seebeck coefficient, electrical conductivity, and electron thermal conductivity can be quantitatively estimated once the spectral conductivity and chemical potential are determined. We also found that these electron transport properties are separately controlled by knowing the fact that the energy range of electrons for these properties are different from the others. It was also revealed that the dimensionless figure of merit ZT=S^2σT/κ, which is generally used as a measure for performance of thermoelectric devices, is less sensitively affected by the scattering of electrons. These facts strongly suggest that the thermoelectric properties are capable of being optimized for thermoelectric materials by using the micro and nano-structures, provided that these characteristic structures in nano and micro-scale cause significant variation in electronic structure rather than in the scattering processes.
