Journal of Materials Chemistry C
Up-conversion charging of a Tb3+-activated garnet phosphor
Tingxing Shi, Feng Liu, Jiahua Zhang and Xiao-Jun Wang
Studies on the up-conversion charging of persistent phosphors are of great academic and practical significance. To date, up-conversion charging designs have been achieved in Cr3+, Mn2+ and Pr3+-activated phosphors. We herein report, for the first time, an up-conversion charging process in the Tb3+-activated garnet phosphor, Gd3Ga5O12:Tb3+, using a 488 nm laser as the excitation source. The delocalized 4f75d state of Tb3+ is excited by absorbing two excitation photons, followed by the charging of the phosphor. Moreover, spectroscopic investigations reveal that an energy-transfer mechanism dominates the up-conversion excitation. This work provides an up-conversion strategy for charging Tb3+-activated phosphors, paving the way toward expanding the scope of persistent phosphors with up-conversion chargeability.