Structural, electronic, and magnetic properties of non-planar doping of BeO in graphene: a DFT study

Abstract

Herein, we performed ab initio calculations to study the structural strain in graphene by non-planar substitution of a polar BeO molecule and analyzed its effect on electronic and magnetic structures. Two modes of doping, i.e., Be within graphene plane (replaced with C atom) with O upright (outside the plane) and vice versa, were investigated in both spin-polarized and non-spin-polarized modes. The resultant strain demolished the sp² hybridization, leading to some interesting effects in the electronic structure. A significant distortion in the structures of the system was realized. It is observed that such a structure distortion causes the induction of energy gaps of varying nature (direct as well as indirect). The highest value of band gap (0.44 eV) is observed in the case where the O atom of the BeO molecule remains drilled through the graphene structure. It is observed that despite the dopant being polar, spin-polarized calculations do not give remarkably different results relative to their non-spin polarized counterpart as no magnetic moment was recorded after inducing spin-polarization. In addition, bonding mechanisms have been discussed for all the cases elaborating significant variations with changes in the BeO orientation as well as the nature of calculations. The amount of band-gap that varies between 0.31 to 0.44 eV is suitable for employing such systems in the manufacturing of field effect transistors. Moreover, the results indicate the possibility of using these systems in the vast field of nano-electronic and spintronic devices. Increasing the supercell size reduces the band gap due to a decrease in concentration.