Low-temperature solution synthesis and characterization of Ce-doped YAG nanoparticles

Monophasic Ce³⁺-doped yttrium aluminum garnet (Ce:YAG) nanoparticles with high crystallinity and tunable grain size ranging from ∼19-30 nm were prepared by a modified co-precipitation process with a follow-up calcination treatment. For the synthesis, aluminum, yttrium, and cerium nitrates were used as starting materials, ammonium sulfate as dispersant, and a combination of ammonium bicarbonate and ammonia as precipitating agent. Influence of precipitation temperature, the pH value of precipitant solutions, aging period, calcination conditions, and Ce-doping level were investigated for controlling the purity, particle size, and photoluminescence performance of the Ce:YAG nanoparticles. High-purity YAG nanoparticles were prepared at pH=10.50-11.00 and calcination temperatures of 850-1100 °C with a calcination time of 3 h. With increasing Ce³⁺ concentration, the peak in the emission spectra of the obtained nanopowders shifted from 529 nm for the 0.67 wt.%-Ce:YAG to 544 nm for the 3.4 wt.%-Ce:YAG, while the strongest photoluminescence intensity was observed for the 1.3 wt.%-Ce:YAG nanoparticles.