Preparation and characterization of bright high quality YAG: Eu3+ thin films grown by sol-gel dip-coating technique

In the present study, highly transparent thin films of europium trivalent (Eu3+) -doped yttrium aluminum garnet (YAG: Eu3+), deposited on quartz substrates with good optical properties were successfully prepared by sol-gel dip-coating technique. Thin film thicknesses were incremented by increasing the number of coated layers. The relationship between the film thickness and its structural and optical properties were highlighted. Prepared thin film samples were characterized by Rutherford Backscattering Spectroscopy (RBS), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), photoluminescence spectroscopy (PL) and UV-Visible spectroscopy. RBS analysis shows that the film thicknesses range from 74 nm to 803 nm. According to XRD results, the single cubic phase of YAG was formed and no impurity phases appeared. Also, the crystallite size increased with the increase of film thickness. FE-SEM images reveal spherical shape particles with the formation of cracks. All samples present a dominate and intense orange emission centered at 594 nm characteristic of magnetic dipole D-5(0) -> F-7(1) transition of Eu3+ ion in the YAG host material. Also, it was found that the emission intensity increases with increasing film thickness and correlated with its density. The UV-Vis spectroscopy revealed that the films were transparent and the degree of transparency depends on the film thickness.