DFT study of X-doped (X= Cu, Ag, Au) boron nitride nanotubes for spintronic and optoelectronic applications

Abstract

In this paper, first-principle calculations of (3,0) and (5,5) single-walled boron nitride nanotubes (BNNT) doped with X-atoms (X = Cu, Ag and Au), in the boron and the nitrogen sites are carried out. A systematic approach based on Pseudo-Potential Plane-Wave (PPPW) method combined with the generalized gradient approximation (GGA) within the density functional theory (DFT) is used to study the influence of X atoms doping on the structural, electronic, optic and magnetic properties of the analyzed BNNT. The structural arrangement in equilibrium conditions shows an outward radial deformation around the X atom in the tube, leading to affecting the electronic properties of the BN nanotubes. Moreover, it is revealed that the doping has a profound implication in inducing significant modification on the band energy of the pristine BNNT. Optoelectronic properties can be estimated by using different empirical models, which are mainly related to the fundamental energy gap, where high optoelectronic proprieties have been recorded. Moreover, the obtained results show that the adsorption of Cu and Au atoms can induce magnetization while no magnetism is observed for the Ag-doped BNNT. Therefore, the magnetic properties of BNNTs can be modified by introducing appropriate doping using X atoms. This makes the Cu and Au-doped BNNT structure potential alternative for developing magnetic and optic nanostructures, which are highly suitable for spintronic and optoelectronic applications.