Work

First-principles study of the thermoelectric properties of quaternary tetradymite BiSbSeTe 2

Year: 2018

Type: article

Abstract: The electronic and phonon transport properties of quaternary tetradymite BiSbSeTe 2 are investigated by using a first-principles approach and Boltzmann transport theory. Unlike the binary counterpart Bi 2 Te 3 , we obtain a pair of Rashba splitting bands induced by the absence of an inversion center. Such unique characteristics could lead to a large Seebeck coefficient even at a relatively higher carrier concentration. Besides, we find an ultralow lattice thermal conductivity of BiSbSeTe 2 , especially along the interlayer direction, which can be traced to the extremely small phonon relaxation time mainly induced by the mixed covalent bonds. As a consequence, a considerably large ZT value of ~2.0 can be obtained at 500 K, indicating that the unique lattice structure of BiSbSeTe 2 caused by isoelectronic substitution could be an advantage to achieve high thermoelectric performance.

Source: Journal of Physics D Applied Physics

DOI: 10.1088/1361-6463/aace7b