Effects of composition and structure on spectral properties of Eu3+-doped yttrium silicate transparent nanocrystalline films by metallorganic decomposition method

Transparent thin films of (EuxY1−x)2SiO5 and (EuxY1−x)2Si2O7 (x=0.005∼0.05) have been prepared using a metallorganic decomposition sol–gel process. A strong room temperature red emission with predominant wavelength at 614 nm, corresponding to the 5D0→7F2 intra-4fn electric transition of Eu3+, has been observed as a function of the annealing temperature. Correlations were observed between optical properties and film structures. As a consequence, a great change in luminescence and CIE coordinates of Eu3+-doped Y2SiO5 at high temperature around 1050 °C was attributed to phase transformation of nanocrystalline films. Upon exposure to the UV source, these thin films have shown bright red-phosphorescent color with excellent color saturation.