Comparison of essential physical properties between pristine armchair silicene nanoribbons and those doped with Ge and As

In this paper, some physical properties of pristine armchair silicene nanoribbons (ASiNR) and those doped with Ge (ASiGeNR) and As (ASiAsNR) using the VASP (Vienna ab initio simulation package) computational program, by using density functional theory. The results show significant differences in the structural and electronic properties between these systems. For ASiGeNR and ASiAsNR, structural parameters such as the distance between two nearest-neighbor atoms in the hexagonal ring, the distance between two farthest atoms, and the buckling height are all larger compared to ASiNR. While ASiNR and ASiGeNR have band gaps of approximately 0.262 eV and 0.2410 eV, respectively, opening at the Γ point, ASiAsNR does not have a band gap. The results indicate that ASiNR and ASiGeNR exhibit semiconductor properties, while ASiAsNR exhibits metallic properties. For ASiGeNR, the substitution of Ge leads to a reduction in bandgap and an increase in thermal conductivity, attributed to the energy level of Ge being close to that of Si. For ASiAsNR, the substitution with As increases the density of states at the top of the valence band, suggesting better electrical conductivity. ASiNR, with its wide bandgap, is suitable for applications in semiconductor devices such as MOSFETs and sensors. ASiGeNR is well-suited for optoelectronic applications such as solar cells or light-emitting diodes (LEDs), while ASiAsNR is appropriate for spintronics or high-speed electronic devices.