First-Principles Investigation on the Impact of Electric Fields on the Electronic Properties of Monolayer SiS and SiS₂ for Nanoelectronic Applications

Abstract

In this study, the structural and electronic properties of monolayer SiSx (x = 1, 2) and the influence of external electric fields were systematically investigated using first-principles density functional theory (DFT) calculations. The computed results reveal that both monolayer SiS and SiS₂ are indirect-gap semiconductors with band gaps of approximately 3.0 eV and 2.2 eV, respectively, as determined using the HSE06 hybrid functional. Notably, the application of an external electric field can effectively and continuously modulate the electronic band structure and band gap of both materials, demonstrating strong potential for field-tunable electronic and optoelectronic devices. These findings not only deepen our understanding of the fundamental electronic properties of SiS-based monolayers but also provide essential theoretical guidance for their exploitation in next-generation nanoelectronic and optoelectronic technologies.