Fluorinating the graphene-like BeO monolayer: A spin-polarized first principles study of the electronic, magnetic and optical properties

Abstract

Abstract Chemical functionalization of low-dimensional materials has been widely employed to create new multifunctional materials with novel properties. In this paper, we present the results of the fluorination effects on the structural, electronic, magnetic, and optical properties of the BeO monolayer. Materials stability is examined by means of the phonon dispersion curves and binding energy. Significant structural changes of the BeO monolayer are induced by the fluorination. The pristine single layer possesses a wide indirect K − Γ band gap of 5.23 eV with no spin-polarization. Either half-metallic or magnetic semiconductor structures with important ferromagnetism can be induced by the half-fluorination, and a total magnetic moment of 1 μ B may be obtained. The full-fluorination produces a magnetism-free material, however causes the indirect-direct gap transition and a considerable reduction of the energy gap to 0.97 eV. The fluorination enhances the BeO monolayer optical properties in the low energy regime, and also the interaction with the light polarized in the z-direction. Our simulations suggest that the fluorination may be an effective approach to tune the BeO single layer physical properties producing new materials, which are expected to find prospective applications in the spintronic and optoelectronic nano-devices.