Structural, electronic and optical properties of pristine and functionalized MgO monolayers: a first principles study

Abstract

In this paper, we present a detailed investigation of the structural, electronic, and optical properties of pristine, nitrogenated, and fluorinated MgO monolayers using ab initio calculations.

Effect of Oxygen Vacancy Defects on Electronic and Optical Properties of $MgO$ Monolayers: First Principles Study

“…Figure 2(a) shows that the valence band maximum (VBM) appears at K symmetric point along with the conduction band minimum (CBM) at γ symmetric point for the pristine MgO monolayer. Our observations agree well with the previous theoretical results [19,24]. All the considered defective monolayers bear non-magnetic characters as previously seen for other oxide monolayers [34,54].…”

“…The negative BE/atom values indicate that all the MgO monolayers are stable with the pristine being the most stable. The stability of P has already been confirmed with phonon dispersion analysis in a previous study [18,24,51,52]. The binding energy of this monolayer is less than that of MgO bulk experimental value (10.26 eV) [53].…”

“…The Fermi energy levels in the figures, represented by dotted lines are set at zero energy. For pristine MgO monolayer, the band gap values obtained with PAW and HSE functional are 3.39 eV and 4.84 eV, respectively, indicating it as a wide band-gap semiconductor as reported earlier [10,11,24,42]. It is to be noted that P is non-magnetic and its band gap is of indirect nature as shown by both the functionals.…”

“…Further, it is well known that the GGA-PBE functional underestimates the energy gap of a system [40]. To overcome this limitation, hybrid functional of Heyd, Scuseria and Ernzerhof (HSE) [41] functional has already been effectively applied earlier [10,11,24,42]. We have therefore used HSE functional with optimized norm-conserving pseudopotentials (ONCV) [43] to achieve accurate electronic band structure of our considered systems.…”

“…M. Yeganeh and F. Kafi investigated the variation in optical properties of graphene like MgO (111) MLs under the application of strain [23]. N and F functionalizations are found to enhance the optical properties of MgO single layer over the pristine [24]. Numbers of experimental and theoretical investigations have addressed the effect of vacancies in the optical properties of MgO bulk, surface and other nanoforms [25,26,27,28].…”