Organic/inorganic optical nanocomposite with highly-doped rare-earth nanoclusters: novel phosphors for white LEDs

Organic/inorganic optical nanocomposite with highly-doped rare-earth (RE) nanoclusters has been developed. The nanocluster, having RE-metal (RE-M) complex alkoxide structure (RE|M(OR)/sub 4/|/sub 3/), was designed to suppress nonradiative transitions due both to multi-phonon relaxation and concentration quenching while maintaining preferable solubility in organic materials. Based on this concept, europium (Eu/sup 3+/)-, terbium (Tb/sup 3+/)-, and cerium (Ce/sup 3+/)-based nanoclusters (RE|Al(OBu/sup 5/)/sub 4/|/sub 3/) dispersed in propyleneglycol /spl alpha/-monomethyl ether, each of which exhibiting red, green, and blue luminescence, respectively, were synthesized. Photoluminescence spectra suggest that these nanoclusters can be good candidates for RGB-type white LEDs. Further, acrylic-resin-based organic/inorganic nanocomposite was successfully fabricated using Eu/sup 3+/|Al(OBu/sup 5/)/sub 4/|/sub 3/.