Electronic and optical properties of a structural defect in 2D MgF_2 monolayer

摘要

In this paper, we have studied structural and optoelectronic properties of 2D pristine MgF_2 monolayer and create the F atom vacancy inside the system. The electronic density of states showed transition from insulator to semiconducting behavior by structural defect induced and corresponding band gaps are 2.98 eV and 2.00 eV for H-phase and T-phase, respectively were obtained, which was computed by using GGA-PBE functional. With the structural defect in MgF_2 system showed the strong hybridization of Mg s-orbital and F p-orbital in the occupied orbital in the valence and conduction band range.. The optical properties were calculated by RPA quasi particles with single-shot GW0 approach. From the imaginary part of dielectric function, it absorbs only Ultraviolet (UV) light. These theoretical investigations suggest that the pristine and defected MgF_2 monolayer system may serve as a superior candidate for UV light absorbing nanodevices.