The Effect of Tb3+ Co-Doping on the Photoluminescence of (Sr,Ba)(2)SiO4:Eu2+

We introduced Tb3+ co-dopants into well-known orthosilicate phosphors such as Sr2SiO4:Eu2+ and (Sr,Ba)(2)SiO4:Eu2+. Tb3+ co-doping had a positive influence on the overall photoluminescence (PL) intensity of beta-Sr2SiO4:Eu2+,Tb3+ and alpha'-(Sr0.7Ba0.3)(2)SiO4:Eu2+, Tb3+. In the absence of barium incorporation, Tb3+ co-doping induced phase transformation of the Sr2SiO4 host from the beta to the alpha' phase, such that the peak location redshifted and the peak intensity decreased significantly. For beta-Sr2SiO4:Eu-0.02(2+) and alpha'-(Sr0.7Ba0.3)(2)SiO4: Eu-0.02(2+), we detected inactive energy transfer from Eu2+ to Tb3+, despite the fact that the PL intensity was improved by the Tb3+ co-doping, meaning that the Eu2+ emission never decreased as the Tb3+ concentration increased. There was clear evidence supporting an energy transfer between Eu2+ and Tb3+ for alpha'-Sr2SiO4: Eu2+,Tb3+ despite no conspicuous practical improvement in the PL properties. The positive influence of Tb3+ co-doping comes not from the energy transfer, but, rather, simply from the local structure change around the Eu2+ activator in the host. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3409560] All rights reserved.