Thermoelectric transport properties of silicon: Toward an ab initio approach

We have combined the Boltzmann transport equation with an ab initio approach to compute the thermoelectric coefficients of semiconductors. Electron-phonon, ionized impurity, and electron-plasmon scattering mechanisms have been taken into account. The electronic band structure and average intervalley deformation potentials for the electron-phonon coupling were obtained from the density functional theory. The linearized Boltzmann equation has then been solved numerically beyond the relaxation-time approximation. Our approach has been applied to crystalline silicon. We present results for the mobility, Seebeck coefficient, and electronic contribution to thermal conductivity as functions of the carrier concentration and temperature. The calculated coefficients are in good quantitative agreement with experimental results.