Rare Earth Activated Phosphors Based on Yttrium Orthovanadate and Related Compounds

The adoption of as a new red ‐emitting primary in color television has stimulated investigation of a new class of phosphors obtained by appropriate substitutions in . Substitution of Y 3+ by Gd 3+ and Lu 3+ provides equally efficient hosts for Eu 3 + with no significant spectral differences. Substitution of Y 3+ by La 3+ leads to a less efficient host with important differences in the emission characteristics of Eu 3+ . Use of rare earth activators ether than Eu 3+ provides a series of phosphors which emit over most of the visible range. Spectral data and preferred concentration ranges are presented as well as the effect of temperature on the fluorescent emission intensities.