Abstract
The material design of type-VIII clathrate Si46 is presented based on first principles. The
structural, electronic, elastic, vibrational, and thermodynamic properties of this hypothetical
material are presented. Our results predict that type-VIII clathrate Si46 is an indirect semiconductor with a bandgap of 1.24 eV. The band structure revealed an interestingly large
number of electron pockets near both conduction and valance band edges. Such a large density
of states near the band edges, which is higher than that of the best thermoelectric materials
discovered so far, can result in a large thermoelectric power factor (>0.004 W m-1 K-2)
making it a promising candidate for thermoelectric applications. The elastic properties as well as the vibrational modes and the phonon state densities of this material were also calculated. Our calculations predict that the heat capacity at constant volume (isochoric) of this clathrate increases smoothly with temperature and approaches the Dulong–Petit
Original language | English |
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Pages (from-to) | 475502-1 to 475502 |
Journal | Journal of Physics Condensed Matter |
State | Published - Nov 15 2013 |