SiGe/h-BN heterostructure with inspired electronic and optical properties: a first-principles study

Abstract

The structure along with the electronic and optical properties of a SiGe/BN monolayer heterostructure were theoretically researched using density functional theory calculations. There are small interactions between a SiGe monolayer and a BN monolayer in the stacking model of a SiGe/BN heterostructure via van der Waals forces. The binding energies of the different stacking models, the DOS, and the charge density difference are calculated and analyzed. According to our investigation, the heterostructure maintains the most unique electronic properties of the SiGe monolayer, especially linear dispersion at the K point, and enlarges the band gap to ∼57 meV, benefiting its application in the microelectronic field. Moreover, the band gap can be modified through external electric fields and strains to a large extent. The optical property is also investigated to find an enhancement effect at the ultraviolet region. In general, the calculated results indicate that the SiGe monolayer layered on the BN substrate possesses great potential in microelectronic and optoelectronic applications.