Spin caloritronics in a graphene-antimonene heterostructure with high figure of merit: a first principle study

In this paper, thermally induced spin current in graphene-antimonene heterostructure is investigated using first-principle density functional theory (DFT) combined with the non-equilibrium Green’s function (NEGF) method. We obtain a higher spin current in the graphene-antimonene heterostructure (Gr-Sb) than in the graphene zigzag nanoribbon (GrZNR). The current versus source temperature shows negative differential behavior. Also, the results show that graphene-antimonene heterostructure's figure of merit coefficient could be ZT = 37 ×10-3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${10}^{-3}$$\end{document} in the energy range – 0.5 eV < E < 0.5 eV, while its value for monolayer graphene is about 4000 times less. These results show that the figure of merit ZT can be increased in the heterostructure of graphene-antimonene; thus, it can be selected as a platform for high-performance thermoelectric technology.