Effect of electric field on Interaction of Na+, Li+ with Defected silicene sheet: DFT study

Silicene as an equivalent of graphene has recently obtained volatile studies due to its many amazing remarkable properties such as topological insulating state, the realization of the quantum spin Hall effect, ultra-high carrier mobility and the existence of the Dirac cone [1-3]. Silicene could be synthesized and provided using perfect semiconductor techniques, but defects are almost obvious during the fabrication process, and their existence strongly affects thermodynamic and electronic properties of two-dimensional materials [4, 5]. In this contribution, we performed calculations to investigate the effect of absent and present of vertical electric field on interaction energy of Na+, Li+ with defected silicene sheet. For this reason, we have examined theoretically the creation of silicene sheet and their defected silicene (divacancies = missing two atom) structure? with Li and Na ions. Calculations were carried out within the framework of density functional theory (DFT) using a local density approximation scheme, as implemented in the Dmol3 package. The generalized-gradient approximation (GGA) for the exchange correlation functional with the parametrization of Perdew − Burke − Ernzerhof (PBE) was used [6, 7]. The double numerical plus polarization (DNP) basis set, 4.4 basis file and Monkhorst-Pack k-point mesh of (6×6×1) and (4×4) supercell. To avoid interactions of the silicene sheet with its periodic images, a vacuum gap of 60 Å in the z direction was used. According to the gained results for defected silicene structure? with Li and Na ions, our calculations show that vertical electric field can impact on interaction energy values structures of silicene and it could be worthwhile strategy for applications of these defects include sensors, batteries, supercapacitors, solar cells and fuel cells.