Influence of europium oxide doping on the structural and optical properties of pulsed laser ablated barium tungstate thin films

Nanostructured Eu2O3 doped Barium tungstate (BaWO4) crystallites are successfully synthesized using pulsed laser deposition (PLD) technique. The influence of different Eu2O3 doping concentrations (1,2,3 & 5 wt.%) on the structural, surface morphological and optical properties are systematically studied using XRD, micro-Raman, SEM, AFM, UV–vis and photoluminescence spectroscopy. All the films are polycrystalline with tetragonal scheelite structure. The vibrational analysis of the atoms in BaWO4 is studied by micro-Raman spectra using factor group analysis. The surface morphological analysis by SEM and AFM reveals the presence of fine nanoparticles with distinct grain boundaries in all the films. The band gap energy variation in the Eu2O3 doped BaWO4 films is in accordance with the variation of the sizes of nano particles in the films. The films with higher Eu3+ doping concentrations (≥2 wt.%) show a PL emission peak centered around 614 nm when excited at 394 nm which can be attributed to the 5D0 → 7F2 (0–2) transition of Eu3+ ion.

Research highlights▶ Study on the influence europium oxide doping on the structural and optical properties of laser ablated barium tungstate thin films is new. ▶ The surface morphological analysis by SEM and AFM reveals the presence of fine nanoparticles with distinct grain boundaries in all the films. ▶ The films with higher Eu3+ doping concentrations (≥2 wt.%) show a PL emission peak centered around 614 nm when excited at 394 nm which can be attributed to the 5D0 → 7F2 (0–2) transition of Eu3+ ion ▶ The observation of PL emission in these films is a new result which can have large practical applications and also it shows that BaWO4 can act as host material for europium ion. ▶ Detailed analysis of the Raman spectra of BaWO4 films are presented.