Density functional theory and ab‐initio molecular dynamics calculations on the opto‐electronic, spintronic, and energies of pure and TiO _x doped monatomic γ‐graphyne

Abstract

In this work, density functional theory and molecular dynamics (MD) calculations are performed on TiO x (ie, x = 1-3) doped γ-graphyne to modify its structural, opto-electronic, and spintronic characteristics. Obtained negative binding energies (E b ) values and MD calculations suggest that TiO x substitution in γ-graphyne is thermodynamically stable. Furthermore, the direction of charge transfer occurs from TiO 1(2) clusters to the γ-graphyne, whereas in case of TiO 3 , γ-graphyne lends its charge carriers to impurity cluster. TiO 2(3) cluster doping converts nonmagnetic γ-graphyne to a magnetic material having $2.00 μ B magnetic moment. TiO doped γ-graphyne displays nonmagnetic narrow band indirect semiconductor behavior at M-point with $1.0 eV band gap.Since TiO 2(3) cluster doped γ-graphynes carried magnetic behavior, hence displayed spin polarized band structures. During spin down band, TiO 2 doped γ-graphyne carries $0.7 eV band gap having n-type dopant nature. Similarly, during spin up channel, TiO 3 doped γ-graphyne carries $0.9 eV direct band gap semiconductor behavior. Blue shift appears in absorption and extinction coefficient plots after TiO x substitution in γ-graphyne. Likewise, static reflectivity and refractive index parameters are improved having maximum of 0.65 and 8 peak intensities, respectively. Our obtained results suggest a viable way forward for making functional hybrid γ-graphynes to be used in opto-electronic and spintronic device applications.