Novel lanthanide-doped Y3-xNaxAl5-yVyO12 garnets: Synthesis, structural and optical properties

In this study the novel garnet-type Y2.47Na0.5Ln0.03Al5O12, Y2.97Ln0.03Al4.95V0.05O12, Y2.92Na0.05Ln0.03Al4.9833V0.0167O12 (Ln = Ce3+, Tb3+, Eu3+) phosphors were successfully synthesized by the sol-gel method for the first time. The structural, morphological and optical properties were characterized by using multiple characterization techniques. The XRD and FTIR results confirmed that all obtained phosphors are monophasic yttrium aluminium garnet compounds, i.e. the doping of Ce3+, Tb3+, Eu3+, Na+, V5+ ions does not induce any impurity phases, indicating the successful incorporation of these dopants into the YAG host. The formation of novel garnets was probed using 27Al, 51V, 23Na MAS NMR techniques. SEM micrographs revealed that almost in all cases, the surface of the obtained luminophores is porous and consists of homogeneously distributed irregular sphere-like shape particles, which tend to form larger agglomerates. The optical properties of obtained compounds were also investigated by recording their excitation and emission spectra and calculating the colour coordinates in the CIE 1931 colour space.