LUMINESCENCE OF Eu:Y3Al5O12, Eu:Lu3Al5O12, AND Eu:GdAlO3 NANOCRYSTALS SYNTHESIZED BY THE SOLUTION COMBUSTION METHOD

Abstract

The nanocrystals of rare-earth garnets, Y₃Al₅O₁₂ and Lu₃Al₅O₁₂, and perovskite GdAlO₃ highly-doped (10-20 at.%) with Eu³⁺ ions are synthesized by the solution combustion technique and subsequent annealing in air at 800 and 1300 °С. The structure, morphology and composition of obtained materials are studied. Under UV excitation, these materials exhibit intense red luminescence. For Eu:GdAlO₃, CIE 1931 color coordinates of the luminescence are (0.632, 0.368), dominant wavelength is 599.6 nm, and color purity is >99%. Judd-Ofelt parameters, luminescence branching ratios and lifetime of the⁵D₀ state of the Eu³⁺ ions are determined. For 10 at.% Eu:GdAlO₃, the luminescence quantum yield reaches 74% and the⁵D₀ lifetime is 1.4 ms. The synthesized materials are promising for red ceramic phosphors.