Thermoelectric properties in monolayer MoS2 nanoribbons with Rashba spin–orbit interaction

• Published in: Journal of materials science 2019, Vol.54 (1), p.467-482
• Main Authors: Shokri, Aliasghar, Salami, Nadia
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Computation; Crystallography and Scattering Methods; Materials Science; Polymer Sciences; Solid Mechanics
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-018-2837-8

In this work, we present a detailed investigation of the influences of intrinsic spin–orbit coupling (ISOC) as well as Rashba spin–orbit coupling (RSOC) on thermoelectric properties of molybdenum disulfide ( MoS 2 ) nanoribbons with armchair and zigzag edges, theoretically. For this purpose, we generalize the tight-binding model including the effects of the ISOC on all the atoms and a RSOC induced by a vertical electric field. By the calculation of the quantum spin-dependent transmission function from the recursive non-equilibrium Green’s function model using the multi-band Slater–Koster tight-binding method, the electrical and thermal currents flowing to the right lead can be obtained from the Landauer–Büttiker formulae. Hence, the temperature-dependent electrical conductance ( G ), the thermal conductivity ( κ ), the Seebeck thermopower ( S ), and the thermoelectric efficiency ( ZT ) are discussed. The results predict a noticeable semiconducting behavior with n type, which exhibits a linear temperature dependence of the gap energy for both nanoribbons. The predicted ZT values demonstrate that the MoS 2 nanoribbons can be optimized to exhibit very good thermoelectric performance in which its value is not affected under influence of the electric field-induced RSOC in the ZMoS 2 nanoribbon (regardless of the AMoS 2 nanoribbon). Based on the used model, a large Seebeck coefficient is obtained in both types of the nanoribbons. Our results may be useful in designing novel thermoelectric devices based on two-dimensional materials as one of suitable nanoscale device.