Site selective behaviour of B, C and N doping in MgO monolayers towards spintronic and optoelectronic applications

Abstract

The electronic, magnetic and optical properties of graphene-like MgO monolayers doped with B, C and N atoms in both Mg and O sites are investigated in the framework of density functional theory. The impurity atoms induce magnetism in the host material irrespective of the sites of substitution. The HSE based hybrid DFT calculations show that the wide electronic band gap semiconducting pristine MgO monolayer becomes metallic due to B and C doping in the Mg site of MgO monolayer system (BMg and CMg). However, rests of the doped monolayers remain semiconducting with appearance of impurity states that lowers their energy band gaps compared to the pristine value. Accordingly, the optical behaviour of the doped systems get tuned making them optically active for a wide spectral range in electromagnetic spectrum starting from infrared to UV region. Therefore, such site selective modulation of electronic and optical properties achieved through substitutional doping in MgO monolayers may be effective for desirable moulding of these materials for spintronic and optoelectronic applications.