Improving the emissive properties of yttrium-based phosphor through internal and external modifications

In this paper, we have proved the possibility of improving the emissive properties of cerium, Ce 3+ , activated yttrium aluminium garnet (YAG:Ce) phosphor both by internally modifying the lattice parameters as a result of adding a codopant and by external silanization of the phosphor particle's surface. The addition of codopant in the form of gadolinium, Gd 3+ , ions was performed using the method of concomitant precipitation of metal cations. The silanization of phosphor was achieved by activating the surface and cross-linking of the (3-aminopropyl) triethoxysilane molecules. By FTIR spectroscopy and X-ray diffraction, we have assessed the influence of internal and external modifications on the structure of phosphor. At the same time, the optical properties using fluorescence spectroscopy were evaluated. The analysis of modified phosphor samples confirmed the improvement of the emissive properties of YAG:Ce and the possibility of manufacturing the white light-emitting devices with a high-efficiency degree as a result of the bathochromic shift, increasing the emission intensity and of the quantum yield. By linking organic compounds with amine terminal groups at YAG:Ce surface, it creates the premises for covalently linking biomolecules, expanding the range of applicability of these fluorescent materials.