Spin–orbit coupling effects on the electronic structure of two-dimensional silicon carbide
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Two-dimensional silicon carbide (2D-SiC) has attracted incredible research attention recently because of its wide bandgap and high exciton binding energy. Here, we focus on the effect of spin–orbit coupling (SOC) on its electronic structure through a detailed first-principles density functional theory study. The calculated electronic band structure and projected electron density of states indicate that Si 3p and C 2p electrons play a vital role in forming the electronic bandgap. The distribution of the real space charge density in the conduction and valence bands further confirms the electronic structure. It is found that inclusion of SOC causes splitting of both the valence and conduction bands. A wide SOC-induced bandgap of ~ 30 meV is observed in this novel material. Moreover, the effect of strain in modulating the bandgap and the SOC interaction is quantified. We find a linear reduction of both the normal and SOC-induced bandgap with increase of the biaxial tensile strain. Bandgap tuning based on such SOC effects may provide a pathway towards future optoelectronic and novel spintronic devices based on 2D-SiC.
KeywordsSpin–orbit coupling Density functional theory Electronic structure 2D-SiC
The authors are grateful to Abu Farzan Mitul of the University of New Mexico, Albuquerque, NM 87131-0001, USA and Md. Soyaeb Hasan of Khulna University of Engineering and Technology for valuable discussions during the writing of this paper. This work was supported by the use of the services and facilities of the UGC-funded research project (grant CASR-45/17/06, 2017–2018) provided by the Committee for Advanced Studies and Research (CASR) at Khulna University of Engineering and Technology, Khulna, Bangladesh.
- 10.Hsueh, H.C., Guo, G.Y., Louie, S.G.: Excitonic effects in the optical properties of a SiC sheet and nanotubes. Phys. Rev. B Condens. Mater. Phys. 84, 404–408 (2011)Google Scholar
- 35.Liu, C.C., Jiang, H., Yao, Y.: Low-energy effective Hamiltonian involving spin-orbit coupling in silicene and two-dimensional germanium and tin. Phys. Rev. B 84, 1–11 (2011)Google Scholar
- 37.Winkler, R.: Spin orbit coupling effects in two dimensional electron and hole systems. STMP 91, 8 (2003)Google Scholar