Buckling effects on electronic and optical properties of BeO monolayer: First principles study

[Display omitted] •The electronic results showed that planar buckling can give rise to tunable band gap as the energy gap decline by increasing planar buckling parameter.•The calculated contributions of bonding orbitals have represented that configuration of sp2 hybridized orbitals have transshaped slightly to sp3 hybridization. Using ab initio study, we apply full potential augmented plane waves plus local orbital and generalized gradient approximation for expanding wave functions and exchange–correlation functional term to investigate the electronic and optical properties of beryllium oxide nanosheet. The different values of planar buckling are considered to study. Also the results for fluorinated BeO nanosheet is compared to corresponding non-fluorinated buckled nanosheet. A red-shift in optical spectra is observed obviously as a result of weakening of σ bonds and increasing the number of π electrons. Also optical transparency property for visible range of the electromagnetic spectrum and vanishing energy-band degeneracy is concluded from our data.