Computational prediction of thermoelectric properties of 2D materials

Abstract

In low dimensional materials, the conversion of thermal to electrical energy via thermoelectric devices gained much more attention when a ZT > 5 was reported in metastable Fe2V0.8W0.2Al thin film (2019 Nature 576 85). In this brief review, we tried to describe the underlying physics of nanostructured thermoelectric materials accompanied by the introduction to enhance the efficiency of energy conversion from one form to another. From this determination, we select the two dimensional (AB type) materials such as ScX (X = P, As), SiX (X = S, Se, N, P, As, Sb, Bi), GeX (X = S, Se, Te), SnX (X = S, Se, Te) and BX (X = S, Se, Te) etc. Different theoretical methods have also been mentioned to study the intrinsic thermoelectric properties which might help in searching experimentally the new and promising thermoelectric materials. We explore the thermoelectric parameters such as Seebeck coefficient, electrical conductivity and thermal conductivity by using density functional theory, Boltzmann transport theory with constant relaxation time approximation and non-equilibrium Green’s function approach. Reduced dimensions potentially expand the thermoelectric efficiency by enhancing the Seebeck coefficient and decrease the thermal conductivity. Theoretical calculations thus recommend the stimulation of the two-dimensional (2D) materials with experimental capabilities in designing and improving the thermoelectric performances.