The effects of Na & Mg adsorption on the electrical properties of SiCNTs: A DFT study

In the present study we focused on the electronic and structural properties of Na and Mg adsorption on the surface of the (6, 6) armchair SiCNTs. The adsorption energy (Eads), band gap energy (Eg), partial density of state (PDOS), chemical potential (μ), global hardness (η), electrophilicity index (ω), global softness (S), work function values (φ) and work function change (Δφ) are calculated by using DFT methods and B3LYP/6-311++G (d, p) level of theory. Adsorption of Na and Mg atoms on the surface of SiCNTs reduce the gap energy (Eg) of nanotube and so the conductivity and chemical reactivity of nanotube/Na or Mg increase significantly from pristine model. The order of decreasing of the Eg values for the studied systems is: SiCNTs > C-SiC/Mg > Si-SiC/Mg > C-SiC/Na > Si-SiC/Na. On the other hand the work function of the SiCNTs/Na or Mg complex alters significantly from pristine model and consequently the field emission current densities of system enhance. The predicted adsorption energies (Eads) follow the order: Si-SiC/Mg> Si-SiC/Na> C-SiC/Mg> C-SiC/Na.