Luminescent properties of cerium-activated garnet series phosphor: Structure and temperature effects

The behaviors of Y, Tb, and Gd garnet phosphor powders activated by cerium were studied. Emission spectra with a continuous yellowish range from green-yellow to yellow-orange were produced by controlling the compositions of the solid solution. By increasing the substitution concentration of large cations in the garnet phosphor, the emission intensity tended to decrease and the temperature sensitivity of phosphors tended to increase. The redshift of the emission wavelength depended on the radius size of the substituted cation at the dodecahedral site of the garnet structure. Using a quantum mechanically based configurational coordinate diagram, the thermal quenching behavior, emission spectra, Stokes shift, nonradiative transitions in different host environments, and activator concentrations are discussed. (C) 2008 The Electrochemical Society.