Tailoring oxygen disparity induced luminescence of Dy3+incorporated WO3 thin films

Pure and Dy doped WO3 thin films have been prepared by the physical vapor deposition method of electron beam evaporation technique under a pressure of 1 x 10-5 mbar. Films start out amorphous and become crystalline when they are annealed at 350 degrees C. The diffraction peaks of the X-ray diffractogram are associated with mixed triclinic and monoclinic phases which is determined by performing Rietveld analysis and confirmed by Raman spectroscopy. X-ray photoelectron spectra of the prepared WO3 thin films confirm the presence of six valent tungsten (W+6) and trivalent Dysprosium (Dy+3) in the samples. The even and homogeneous distribution of the particles is visible in SEM pictures of the prepared WO3 thin films. The energy band gap values show a significant decrease on annealing and fall more with Dy doping as a result of the emergence of intermediate states. The annealed films have superior transmittance compared to the non-annealed films which are in amorphous state The prepared thin films' PL emission spectra at 410 nm excitation wavelength exhibit blue, green, and yellowish green emissions as a result of optical band-to-band transitions of oxygen vacancies. Due to the existence of defects like oxygen vacancies, strain, etc., amorphous system, or non-annealed films, have shown better photoluminescence at higher rare earth ion concentration than crystalline system, or annealed films. After annealing the thin films, the overall colour hue of the emitted light can be shown to change from cold white to warm white using the Commission International de l'Eclairage (CIE) diagram. These findings imply that numerous lighting applications can make use of the prepared thin films. According to magnetic experiments, Ferromagnetism (FM) increases with Dy doping due to disparity in oxygen vacancies which is consistent with the results of the Pl experiment. The BMP model was used to discuss these results. The magnetic parameters derived from the fitted data are in good accord with the literature, and the experimental results suit the BMP model well.