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

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 TiO₁₍₂₎ clusters to the γ-graphyne, whereas in case of TiO₃, γ-graphyne lends its charge carriers to impurity cluster. TiO₂₍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 TiO₂₍₃₎ cluster doped γ-graphynes carried magnetic behavior, hence displayed spin polarized band structures. During spin down band, TiO₂ doped γ-graphyne carries ~0.7 eV band gap having n-type dopant nature. Similarly, during spin up channel, TiO₃ 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.