Ultraviolet and visible upconversion luminescence in Y2O3:Er3+, Gd3+ microcrystals by 1.55 mu m excitation

摘要

Upconversion (UC) emission spectra of Y2O3:Er3+ (3 mol. %), Gd3+ (0, 10, 20, and 40 mol. %) microcrystals were studied under 1.55 mu m excitation. Ultraviolet (UV) UC from the L-2(15/2), H-2(9/2), D-4(1/2), D-4(3/2), D-4(7/2), D-4(5/2), D-2(5/2), P-2(1/2), P-2(3/2), (4)G(11/2), and (2)G(9/2) levels in Er3+ and from the D-6(1/2) and P-6(7/2) levels in Gd3+ were obtained. Enhancements of UV UC emissions of Er3+ were observed in Y2O3:Er3+, Gd3+. The cooperative energy transfer from Er3+ to Gd3+ and the energy transfer from Gd3+ to Er3+ ions were thought to be the possible mechanisms for these enhancements. This phenomenon provides a new idea for investigating the enhancement of UC radiations in rare-earth ion doped materials. The dependencies of UC emissions on pump power and dopant concentration were also studied for understanding possible UC mechanisms. (C) 2015 Optical Society of America