Performance Parameters of Thermoelectric Materials

is the Boltzmann constant, e is the electron charge, h is the Planck constant, m is the carrier effective mass, n is the carrier concentration, and /x is the carrier mobility. 

Thermal transport, referred as the heat transfer process within the materials, is mainly done by the lattice vibration (i.e., phonons) and the carrier movement from the micro-perspect. Therefore, for semiconductor materials in extrinsic excitation region, the thermal conductivity is primarily the sum of the lattice thermal conductivity Ki and the carrier thermal conductivity i.e., k = k + k. As the supporter of charge and heat energy, carriers in crystal not only contribute to the electrical conductivity, but also to the thermal transport, when they move in a certain direction. According to the Wiedemann-Franz law, the electronic contribution to thermal conductivity can be defined by Eq. 1.6 [14]  

2 Interdependence of the Seebeck (5), electrical conductivity (h, electronic thermal conductivity k, and lattice thermal conductivity (ki) 

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