Blue-Emitting Phosphor of YInGe[sub 2]O[sub 7] Doped with Tm[sup 3+] Ions

samples, with , exhibit an emission in the blue region with a dominant wavelength of at . The energy is absorbed by the Tm 3+ ion to the emitting level, then transferred to a lower state via radiative transition. A single exponential decay behavior was observed for diluted samples, and a nonexponential decay behavior occurred when was doped with a higher ion concentration. The saturation of emission intensity excited by intra-4f transitions occurred at a concentration of , indicating that the concentration quenching is active when .