Gas adsorption effects on electronic and magnetic properties of triangular graphene antidot lattices

Abstract

The adsorption effects of small molecules (H2O, CO, NH3, NO2) and large molecules (Tetracyanoquinodimethane (TCNQ) and Tetrafluoro-tetracyanoquinodimethane (F4TCNQ)) on electronic and magnetic properties of two triangular graphene antidot lattices (GALs), [10, 3, 6]RTA and [10, 5]ETA, are investigated by means of first-principles calculations. We find that CO, NO2, TCNQ, and F4TCNQ molecules are chemisorbed by both antidots, whereas NH3 is physisorbed (chemisorbed) by [10, 5]ETA ([10, 3, 6]RTA) structure. H2O, CO, NH3 molecules reveal no significant effect on electronic and magnetic properties of these antidot structures. The adsorbed NO2 molecules affect the energy gap of GALs by changing their electronic structure from semiconducting to half-metal nature. This suggests that both GALs can act as efficient NO2 sensors. The adsorption of TCNQ and F4TCNQ molecules on GALs induces flat bands in the vicinity of the Fermi energy and also turn the electronic structure of antidot lattices to half-metallicity. Among the small and large molecules, NO2 molecules induce the most total magnetic moment, paving the way to make magnetic GAL-based devices.