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.
The structural and electronic properties of sulfur-doped armchair stanene nanoribbons (ASnNRs) have been investigated using Density Functional Theory (DFT). The diverse structural and electronic characteristics induced by the substitution of sulfur atoms were comprehensively analyzed through first-principles calculations, including formation energy, optimized structural parameters, projected density of states (PDOS), and spatial charge density distribution. Various doping configurations were considered by replacing Sn atoms with S at different concentrations and atomic positions, resulting in characteristic doping types such as single-atom doping (top-1S, valley-1S), two-atom doping (ortho, meta, para), and full 1:1 substitution with a 6Sn–6S structure. The results reveal significant changes in the bandgap, increasing slightly from 0.26eV in the pristine state to approximately 0.34eV in the meta configuration, moderately decreasing to 0.15eV in the 100% substitution case, and sharply decreasing in the other configurations. Moreover, most sulfur-doped configurations exhibit non-magnetic behavior similar to pristine ASnNRs, while strong magnetism emerges only in the fully substituted 100% case. These findings demonstrate that sulfur doping can fundamentally modify the electronic and magnetic properties of the material, highlighting its potential application in future spintronic devices.
The paper presents the results of a study on the essential physical properties of armchair SiSn nanoribbon (SiSnNR) material, based on density functional theory (DFT) using the quantum simulation program VASP. Structural parameters are highlighted along with electronic and optical properties. The findings reveal that SiSnNR exhibits significant differences in bond lengths, bond angles, and buckling compared to SiNR and SnNR. SiSnNR demonstrates semiconducting properties, with a direct band gap width of approximately 0.3123Å calculated using GGA-PBE, increasing to 0.5892Å when using the hybrid HSE06 functional. The results indicate that Sn atoms primarily contribute to energy bands below the Fermi level, while Si atoms contribute more to higher energy levels. The study also highlights the overlap of py and pz orbitals, leading to sp2 and sp3 hybridization. In terms of optical properties, the energy range from 3 to 5eV is where SiSnNR exhibits the strongest light absorption. The largest number of electron-hole pairs is generated within the energy range of 8-10eV, resulting in intense optical absorption and transitions in this region.
This study investigates the structural and electronic properties of Au-doped silicene nanoribbons (SiNRs) under the influence of an external electric field of 0.4 eV/Å, utilizing density functional theory (DFT). The stability and structural integrity of SiNRs following Au doping are assessed, considering two distinct doping configurations: the top configuration and the valley configuration, where each unit cell incorporates a single Au atom. The formation energies of the doped systems are calculated to evaluate their thermodynamic stability based on DFT principles. Furthermore, detailed analyses of the density of states (DOS) and energy band structures are conducted. Both doping configurations exhibit metallic characteristics, indicating potential applicability in future nanoelectronic devices.
In the paper, we investigate the structure and electronic properties of the pristine germanene nanoribbon and four adsorption configurations of 1F and 2F on the substrate of germanene nanoribbon. We obtained the parameters of the most stable structures of pristine germanene nanoribbon and four adsorption configurations. The band structure and the density of state and the part density of state for each element were also obtained. Findings show the adsorption configuration of 1F-GeNR.bridge has no band structure, while other configurations are semimetals with band gap from 0.175eV to 0.67eV; both four adsorption configurations are chemisorption and non-magnetic. The charge distribution of all configurations also was investigated; it showed that there is a charge shift from Ge atoms towards F atoms due to their electronegativity difference.
Applying first-principles calculations, the investigation of the geometrical and electronic properties of Pr adsorption armchair silicene nanoribbons structure has been established. The results show that the bandgap doped Pr has been changed, which is the case for chemical adsorption on the surface of ASiNRs; this material became metallic with the peak of valance band contact fermi level. Moreover, the survey to find the optimal height 1.82 Å of Pr and 2.24 Å bond length Si-Si, and Si-Si-Si bond angle 108005’, energy adsorption is -7.65 eV, buckling is 0.43 Å with structure stability close to the pristine case, has brought good results for actively creating newly applied materials for the spintronic and optoelectronics field in the future.