Influence of dysprosium ions on structural, optical, luminescence properties and photocatalytic ability of spin coated dysprosium ions doped TiO2 thin films

The rare earth Dy3+ ions doped TiO2 (Dy-TiO2) thin films were spin-coated on glass substrates. The X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy, transmission electron microscopy (TEM), Raman spectroscopy, ultraviolet-visible spectrophotometer, and a fluorescence spectrometer were used to study the structural, compositional, and optical properties of Dy-TiO2 films. The XRD studies revealed the presence of a tetragonal crystal structure with an anatase phase. The crystallite size of Dy3+ ions doped TiO2 nanocrystals declined with the amounts of Dy doping. TEM analysis of 1% Dy3+ ions doped TiO2 and 2% Dy3+ ions doped TiO2 films revealed the particles like spherical shape with the average size of about 10.5 nm and 9.5 nm, respectively. The Raman spectra of Dy-TiO2 films revealed the formation of the anatase phase. The band gap decreased from 3.32 to 2.60 eV with an increase in the Dy3+ doping concentration. At 388 nm excitation, obtained the strong luminescence emission peaks at 482 nm and 577 nm are corresponding to the 4F9/2 -> 6H15/2 magnetic dipole transition and 4F9/2 -> 6H13/2 electric dipole allowed transitions, respectively. The nanostructured 1%Dy doped TiO2 film showing significant color coordinates (0.3310, 0.3881) with suitable correlated color temperature (5560 K) might have potential applications in the white light-emitting diodes. The decay lifetime of the 4F9/2 excited level of Dy3+ions had measured by the biexponential fitting of the decay profiles. Dy3+ ion-doped TiO2 films exhibit a strong photocatalytic performance. The degradation efficiencies typically increase with the cu-mulative quantity of Dy3+ doping for the visible light degradation of methyl orange.