We present a theoretical study of the structural, electronic, and transport properties of bulk ${\mathrm{Bi}}_2{\mathrm{Te}}_3$ within density functional theory taking into account the van der Waals interactions (vdW) and the quasiparticle self-energy corrections. It is found that the optB86b-vdW functional can well reproduce the experimental lattice constants and interlayer distances for ${\mathrm{Bi}}_2{\mathrm{Te}}_3$. Based on the fully optimized structure, the band structure of ${\mathrm{Bi}}_2{\mathrm{Te}}_3$ is obtained from first-principles calculations with the GW approximation and the Wannier function interpolation method. The global band extrema are found to be off the high-symmetry lines, and the real energy band calculated is in good agreement with that measured experimentally. In combination with the Boltzmann theory, the GW calculations also give accurate prediction of the transport properties, and the calculated thermoelectric coefficients of ${\mathrm{Bi}}_2{\mathrm{Te}}_3$ almost coincide with the experimental data.

• Received 21 May 2014
• Revised 27 July 2014

DOI:https://doi.org/10.1103/PhysRevB.90.085118