Synthesis and photoluminescent properties of Y2O3

Dense and transparent Y2O3:Eu3+ films were prepared by the sol-gel process and dip-coating technique from an yttrium 2-4 pentanedionate, europium nitrate and a methanol solution modified with F127 pluronic acid, by incorporation of acetic acid as pH modifier and acetylacetone as sol stabilizer. It was evaluated the effect of the F127/Y molar relationship (0, 0.1, 0.2, 1.0, 1.2 and 5.0) on the structure and photoluminiscent properties of the derived thin films. After 3 dipping-cycles, XRD results showed that the F127-modified films began to crystallize at 600°C into the cubic structure, and from 800°C, was found that the presence of F127 changes the preferential orientation from a [left angle bracket]100[right angle bracket] orientation, for the non-modified sample, to a [left angle bracket]111[right angle bracket] orientation, for the modified ones. M-lines spectroscopy characterization showed that the maximum thickness of the films modified and annealed at 900°C was 1937 nm (ρ = 4.87 g cm-3, η = 1.887), compared with the 881 nm (ρ = 4.94 g cm-3, η = 1.907) for a non-modified sample. Differential thermal analysis (DTA) and infrared spectroscopy (FTIR) were carried out to evaluate the chemical and structural evolution of the xerogel formed during the annealing process. AFM micrographs showed smooth crack-free surface (Ra = 9.2 nm) on a F127/Y = 0.2 sample. Finally, the films presented a typical Eu3+ reddish emission at 611 nm (Do [arrow right] 7F2), which was analyzed as function of the F127 pluronic content and the annealing temperature.