Optical studies of Y3(Al,Ga)5O12:Ce3+,Cr3+,Nd3+ nano-phosphors obtained by the Pechini method

The Y-3(Al,Ga)(5)O-12:Ce3+,Cr3+,Nd3+ (YAGG) nano-phosphors with homogeneous particle-size distribution, low aggregation and average crystalline size of about 65 nm were obtained using a modified Pechini method. Only slight aggregation of the crystallites occurs after post-annealing at 1100 degrees C. The intense Ce3+ bands in the excitation spectra of the Ce3+,Cr3+,Nd3+ co-doped materials monitoring the Cr3+ emission at 690 nm indicate energy transfer from Ce(3+ )to Cr3+. Weak Nd3+ lines are observed, as well. In addition, the emission of Nd3+ at 1060 nm with excitation of Ce3+ and Cr3+ confirms the Ce3+/Cr3+ to Nd3+ energy transfer. The short average luminescence decay times for the Ce3+ emission indicate the Ce3+/Cr3+ to Nd3+ energy transfer. Eventually, the Y-3(Al,Ga)(5)O-12:Ce3+,Cr3+,Nd(3+ )nano-phosphors exhibit persistent luminescence originating from the 4f(3) -> 4f(3) transitions of Nd(3+ )which matches well to the first biological window to be used in bioimaging applications. (C) 2019 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.