Green-emitting phosphor of LaAlGe2O7: Tb3+ under near-UV irradiation

As the Tb3+-doped LaAlGe2O7 phosphors were synthesized by solid-state method, their characterization and luminescent properties were also investigated. The extraordinary excitation spectra showed only intense f-f transition of Tb3+ ions around near-UV region, while the 4f-5d transition could be neglected. Under excitation, the as-obtained powders emitted bright green light at 544 nm (D-5(4) -> F-7(5)). By analyzing the decay curves, the energy migration between Tb3+ ions is conspicuous in D-5(3) -> F-7(5) transition due to the cross-relaxation in LaAlGe2O7. One of the interesting results of this work is that the excitation spectrum of the phosphor and the emission spectrum of the near-UV light-emitting diode (LED) have closely overlapped, which provides the potential as a near-UV LED converted phosphor in solid state lighting technology. (c) 2006 The Electrochemical Society.