Electronic structures of multilayer two-dimensional silicon carbide with oriented misalignment

Abstract

The direct bandgap is favored for optoelectronic applications, such as light emitting or laser diodes and solar cells. While monolayer two-dimensional graphene-like silicon carbide (2d-SiC) possesses a moderate direct bandgap, multilayer 2d-SiC was recently found to exhibit an indirect bandgap. In this paper, our ab initio electronic study demonstrates that a controllable direct bandgap of bilayer/trilayer 2d-SiC can be realized via the interlayer oriented misalignment, where their direct-bandgap character can be maintained for most rotation angles. This misalignment-induced direct bandgap shows a decreasing tendency with a larger commensuration cell, where the minimum direct optical transition frequency can vary from infrared to visible. Our work implies that the interlayer oriented misalignment is a crucial way to tailor the electronic structures of multilayer 2d-SiC, facilitating potential applications for optoelectronic devices.