▎ 摘　　要

Opening a desirable gap in semimetallic silicene and graphene is very important for extending their application in optoelectronics devices. Mixing silicon and carbon can provide a novel way to open their gaps by forming the graphene-like siligraphene. Here, employing theoretical calculations, a complete investigation on the graphenelike SiC2 is provided. The calculations reveal that the pristine SiC2 has a strongly dynamical stabilities. It is a direct semiconductor with a moderate G(0)W(0) gap, which can be linearly modulated by the exerted biaxial strain. Also, the SiC2 exhibits superior optical absorption for the near-infrared and visible parts of sunlight and possesses a large exciton binding energy. The applied biaxial strain can bring a variation of optical transitions in the SiC2, leading to a significant red-shift of the optical absorption peaks. These findings suggest that the SiC2 holds a great potential for nanoelectronics and optoelectronics applications.