Transparent and highly luminescent dysprosium- doped GdVO₄ thin films fabricated by pulsed laser deposition

Transparent, luminescent thin films of Dy^3 +-doped GdVO₄ were fabricated by pulsed laser deposition technique on quartz substrates. Thin film structure, morphology and optical properties were investigated and discussed in detail. X-ray analysis shows relatively intense reflection peaks confirming that as-deposited films are highly crystalline with strong (200) preferred orientation. Cross-sectional scanning electron microscopy shows relatively dense film with an average thickness of ~ 340 nm. Band gap of Dy^3 +-doped GdVO₄ thin film, estimated from diffuse reflectance spectrum, is 3.61 eV. Refractive index and extinction coefficient of thin films as a function of wavelength are extracted from ellipsometric spectra. The photoluminescent emission spectra have two dominant bands: one in the yellow (~ 573 nm, ⁴F_9/2 → ⁶H_13/2 transition) followed by the other in the blue (~ 484 nm, ⁴F_9/2 → ⁶H_15/2 transition) region resulting in the emission color placed in the white light region.