Solvothermal fabrication and luminescent properties of nanoLuAG:Ce phosphors

Nanosized Ce-doped lutetium aluminium garnet (LuAG:Ce) phosphors have been synthesised by a solvothermal method using ethylenediamine as the solvent and metal nitrates as the starting materials. The phase development, the morphology and the luminescent properties of the prepared phosphors were investigated with X-ray diffractometry, transmission electron microscopy and photoluminescence spectra, which showed that phosphors of high phase purity resulted after heating for 8 h at a low temperature of 230^oC. This powder possesses good dispersivity, suffers little or no aggregation and has an average grain size of 220 nm with narrow size distribution, hence, it may be exploited for the fabrication of LuAG:Ce optical ceramics. Its excitation and emission spectra have also been examined, which confirms the transitions between the 4f and the 5d states of the Ce³⁺ ions as the photoluminescence mechanism. The photoluminescence decay showed almost identical components compared with the LuAG:Ce single crystal, which further proves that the obtained nanosized phosphors have been well crystallised.