RESUMO
In the present the authors are trying to work out how the quantum efficiency depends on the nanocrystalline size. Cubic nanocrystalline Y2O3 : Eu3+ samples were prepared by chemical self-combustion. The bulk Y2O3 : Eu3+ was obtained by annealing the nanocrystalline at 1 000 degrees C for 2 h. The emission spectra, XRD and fluorescence decay showed that the emission intensities are increased and fluorescence decay becomes slow with an increase in particle diameter of the samples. Two routes were used to estimate the quantum efficiency of the 5D0 level of Eu3+ at C2 site. The quantum efficiencies of 5D0 level of Eu3+ at C2 site in the samples depend on the nanocrystalline sizes. Finally, a detailed discussion about these two approaches for estimating the quantum efficiencies was made.
RESUMO
Y(P, V)O4 :Eu3+ phosphors with good morphology for plasma display panels have been prepared via coprecipitation reaction. The phosphor was characterized by SEM and photoluminescence under UV (325 nm)and VUV (147 nm) excitation. The emission spectra depending on temperature under 325 nm excitation by laser indicated that there exist energy transfer between VO4(3-) group and Eu3+ ion. Under 147 nm excitation, the most intense emission peaks of commercial (Y,Gd)BO3 :Eu3+ phosphor range around 593 nm, and those of Y(P, V)O4 :Eu3+ phosphors prepared by coprecipitation reaction ranged around 619 nm. The red emission color purity of Y(P, V)O4 :Eu3+ phosphor is much better than that of (Y,Gd)BO3: Eu3+, and its relative emission intensity is almost close to that of the commercial phosphor.