Luminescence of Eu:Y3Al5O12, Eu:Lu3Al5O12, and Eu:GdAlO3 Nanocrystals Synthesized by Solution Combustion

Nanocrystals of rare-earth garnets Y3Al5O12 and Lu3Al5O12 and perovskite GdAlO3 highly doped (10–20 at%) with Eu3+ are synthesized by the solution combustion technique and subsequent annealing in air at 800 and 1300oC. Their structure, morphology, and phase composition are studied. These materials exhibit intense red luminescence under UV excitation. Eu:GdAlO3 luminescence has CIE 1931 color coordinates (0.632, 0.368); dominant wavelength, 599.6 nm; and color purity, >99%. Judd–Ofelt parameters, luminescence branching ratios, and lifetimes of the Eu3+ 5D0 state are determined. The luminescence quantum yield for Eu:GdAlO3 (10 at%) reaches 74% with a lifetime of 1.4 ms for the 5D0 state. The synthesized materials are promising for red ceramic phosphors.