  Motivated by recent experimental realizations of quintuple atomic layer films
of Bi2Te3,the thermoelectric figure of merit, ZT, of the quintuple layer is
calculated and found to increase by a factor of 10 (ZT = 7.2) compared to that
of the bulk at room temperature. The large enhancement in ZT results from the
change in the distribution of the valence band density of modes brought about
by the quantum confinement in the thin film. The theoretical model uses ab
initio electronic structure calculations (VASP) with full quantum-mechanical
structure relaxation combined with a Landauer formalism for the linear-response
transport coefficients.
