Synthesis and luminescence properties of phase-pure ultrafine Y2.9Tb0.1Al5−xGaxO12 phosphors

Ultrafine Y2.9Tb0.1Al5−xGaxO12 phosphor powders with different Ga concentration were prepared by a nitrate–citrate sol–gel combustion process. Mono-phase cubic phosphors were obtained at 900 °C by directly crystallizing from amorphous materials determined by X-ray diffraction (XRD) technique and no intermediate phase was observed. The resultant phosphor powders heat-treated at 1000 °C are uniform with good dispersity and the particle size is about 80 nm. The photoluminescence (PL) spectra of Tb3+ substituted for Y3+ in Yttrium aluminum garnet (Y3Al5O12, YAG) with different Ga concentrations were measured on samples calcined at 1000 °C. The luminescence intensity was effectively improved because of the replacement of Al with Ga in YAG.