Electronic structure of SLSiN under charge density modulation

First-principles density-functional theory calculations were carried out to assess how incremental unit-cell charging alters the electronic behavior of SLSiN (single-layer Si$_3$N$_4$). The net charge per cell was systematically tuned from $n\,=\,0$ (the neutral/reference configuration) to $n\,=\,\pm\,1,\pm\,2$, and $\pm\,3$ elementary charges, and for each charged configuration the band structure and density of states were evaluated at the PBE level. In its neutral state, SLSiN exhibits zero electronegativity, signifying both its indifference to additional electron density and its intrinsic stability when integrated into heterostructures. Altogether, these results reveal that precise control of the charge density can drive SLSiN across an insulator-to-metal transition.