Emission-color control of Eu-doped Li2BaMgP2O8 by UV-vis photostimulation

This paper demonstrates emission-color regulation of Li2BaMgP2O8: Eu phosphor by UV-vis photostimulation. Li2BaMgP2O8: Eu mainly shows Eu3+-derived orange emission under UV excitation if it is prepared by hightemperature solid-state reaction in air. When the Eu3+-containing Li2BaMgP2O8 is exposed to 200-nm stimulation light, 463-nm emission arises asymptotically with stimulation time. Consequently, the resultant emission color gradually becomes bluish. According to the results of ESR spectroscopy, Li2BaMgP2O8 releases mobile electrons when exposed to stimulation light in the range of the absorption band. Being associated with an Eu3+ ion, the mobile electron forms Eu3+-e- aggregates, the origin of the 463-nm emission. Since the following Eu3+-e- & REVARR; Eu2+ equilibrium reaction can be statistically controlled by proper choice of stimulation-light wavelength, it is possible to regulate the resultant emission color by photostimulation.