Effects of boron impurity on optical properties of zinc oxide nanosheets: A first-principles prediction

This study deals with the electronic and optical properties of pure zinc oxide nanosheets (ZnONSs) in the presence of boron impurity by ab initio calculations on the basis of the density functional theory (DFT). The results indicate that in low impurity, the half-metallic feature is induced mainly due to the contribution of B p orbital, while with the increase of impurity concentration, depending on the sites of B dopants, the nonmagnetic semiconductor, magnetic semiconductor and magnetic metal are achieved. Moreover, findings elucidate that the injection of B dopants plays a major role in enhancing the optical response of ZnONSs. The obtained results reveal that the optical behavior appearing in B-doped ZnONSs depends not only on the doping rate but also on the distance between two B impurities. Generally, in comparison to the pure ZnONS, both the imaginary part of the dielectric function and the absorption coefficient spectra of the B-doped ZnONSs show a shift toward lower energies (red shift), reflecting the reduction of the band gap.