Figure of merit. ZT values as functions of temperature and chemical potential for Bi2Te3 2D thin films with thickness 1QL (a), 2QL (c), and 3QL (e); and the 3D superlattice with a = 1QL (b), 2QL (d) and 3QL (f). For the a = 1QL case, c = 1QL, b and d = 10 nm; for the a = 2QL case, c = 2QL, b = 7.5 nm and d = 10 nm; for the a = 3QL case, c = 3QL, b = 7.5 nm and d = 10 nm. The zero of energy is chosen to be at the center of the surface gap.
Fan et al. Nanoscale Research Letters 2012 7:570 doi:10.1186/1556-276X-7-570