Up-conversion luminescence of new phosphors of Gd3Al5O12:Yb/Er stabilized with Lu3+

The metastable garnet lattice of Yb/Er co-doped Gd3Al5O12 (GdAG:Yb/Er) has been effectively stabilized by doping with significantly smaller Lu3+ to form (Gd,Lu)AG:Yb/Er solid solutions. The phase-pure (Gd,Lu)AG:Yb/Er garnet particles have been successfully achieved by calcining their respective precursors synthesized via carbonate co-precipitation. Partially replacing Gd3+ with Lu3+ up to 50 at% (x=0.5) not only lowers the temperature of garnet crystallization, but also raises the theoretical density of the material. The resultant [(Gd1-xLux)(0.948)Yb0.05Er0.002]AG (x=0.1- 0.5) powders, with good dispersion and fairly uniform particle morphology, exhibit strong green (similar to 510 to 590 nm, H-2(11/2), S-4(3/2)-> I-4(15/2) transitions of Er3+) and red (similar to 635 to 700 nm, (F9/2 -> I15/2)-F-4-I-4 transition of Er3+) emissions under 978 am laser excitation. The Lu3+ incorporation effect on the visible emission color and intensity of Er3+, as well as the dependence of emission intensity on pumping power were all discussed in detail. The up-conversion phosphor of Yb/Er codoped (Gd,Lu)AG garnet developed in this work may potentially be used as a new type of luminescent material. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.