Nanometre-sized yttrium aluminum garnet doped with Ce3+ (YAG : Ce) crystals were prepared at a low temperatures by use of an environmentally-friendly wet process, in which an alcohol-water mixture with metal salts is refluxed without any addition of surfactants or adsorbing ligands. All of the YAG : Ce particles with 0.1-10 mol% of Ce3+ ions were found to be nanocrystals. YAG : Ce nanocrystals emitted at a 532 nm wavelength with the excitation light at 454 nm. The highest quantum efficiency was achieved at a very small Ce3+ content of 0.3 mol %. The decay curve of the fluorescence consisted of the three exponential terms, and the average fluorescence lifetime was around 110 ns irrespective of the Ce3+ concentration.
Keywords: YAG, Environmentally-friendly wet process, Nanocrystals, Quantum efficiency, Ce3+ concentration, Fluorescence lifetime