AL-DOPED SILICENE NANORIBBONS IN AN EXTERNAL ELECTRIC FIELD

By Hoang Van Ngoc
DOI: 10.37550/tdmu.EJS/2026.01.705

Silicene nanoribbons (SiNRs), as one-dimensional derivatives of silicene, exhibit highly anisotropic charge transport and hold significant promise for future nanoelectronics applications. In this work, we systematically investigate the structural stability and electronic properties of hydrogen-passivated SiNRs doped with aluminum using first-principles density functional theory calculations performed with the VASP package. Several possible Al substitutional doping configurations are examined, among which three representative geometries-top, valley, and 1-1 arrangements-are identified as energetically stable, while other configurations undergo severe structural distortions or bond breaking during structural relaxation. Formation energy analysis indicates that the 1-1 alloy configuration is the most thermodynamically favorable due to the symmetric distribution of Al dopants and a balanced local bonding environment. Electronic structure calculations reveal that pristine hydrogenated SiNRs are narrow-gap semiconductors with a band gap of approximately 0.325 eV, whereas all stable Al-doped systems undergo a transition to semi-metallic behavior. This electronic transformation originates from the incorporation of group-III aluminum atoms, which introduce hole carriers and shift the Fermi level, leading to enhanced electrical conductivity. In addition, the tunability of the electronic properties is further explored under a constant external electric field of 0.15 eV/Å, demonstrating additional control over the electronic response of the doped nanoribbons. These results highlight aluminum doping, in combination with external electric-field modulation, as an effective strategy for tailoring the electronic characteristics of silicene nanoribbons and suggest promising opportunities for the design of low-dimensional materials with controllable transport properties for advanced nanoelectronics and optoelectronic applications.