Abstract
In this work, utilizing the ab initio Density functional theory DFT, we aim to study theimpacts hydrogen H edge atom passivation on the structural, stability and electronic properties ofplanar bare (without H- edge passivation) Silicene NanoRibbon (PLSiNRs) with either zigzag(PLZSiNRs) or armchair (PLASiNRs) edges on both sides. We found that the edge Si–Si bonds areshorter than the inner ones with identical orientation, implying a contraction relaxation of edge Si atoms but the length of the Si–H bond is always 1.5 A°. Our calculations demonstrated existence of flat bands which cause metallicity in PLZSiNRs- with appearance of a nearly flat band in the ZSiNRs edges near the Fermi level, indicating the presence of a localized edge state. Clearly all PLASiNR-H are nonmagnetic semiconductors with controllable band gaps depending on the ribbon’s width.The band gaps of PLASiNRs–H present oscillatory behavior and can be classified into threebranches Eg(3n +1) > Eg(3n) > Eg(3n +2), where n is an integer. Our results provide that the edge hydrogenation(-H) can be used to tune the structural, stability and electronic properties of a bare PLSiNRs and it is a key issue to integrate PLZSiNRs-H and PLASiNR-H integrate electronic devices like field-effect transistors (FETs) and energy materials.
Highlights
Electronic properties of silicene armchair nanoribbons were investigated.
Density functional theory calculations were performed using VASP.
Edge passivation significantly modifies the band gap of the nanoribbons.
Magnetic behavior depends on ribbon width and edge configuration.
Results suggest promising applications in nanoelectronic devices.