Electronic properties of bilayer g-SiC3 system.

In this paper, using first-principles calculations based on density function theory, we systematically investigate the electronic structures and properties of the bilayer g-SiC₃ systems. Among all three bilayer g-SiC₃ systems considered here, the AA stacking (all C/Si atoms in upper SiC₃ layer lie above the C/Si atoms in lower SiC₃ layer) with an indirect bandgap is most stable. The bandgap calculated by PBE and HSE06 are 1.380 eV and 1.959 eV, respectively. Our results revealed that the bandgap could be modulated effectively by applying in-plane biaxial compressing/stretching or vertical strain along the 'z' axis. When the tensile stress reaches 3%, the bilayer AA g-SiC₃ system changes from semiconductor to semimetal. Moreover, under vertical stretching of ∆d = 0.4 Å (d = 2.83 Å), the bilayer AA g-SiC₃ turns from an indirect bandgap semiconductor to a direct bandgap semiconductor, which is attractive for realizing the nanoscale multi-functional device applications. Our results provide a theoretical understanding for future SiC₃-based electronic nanodevices with controlled bandgaps. [ABSTRACT FROM AUTHOR]