NIR to Visible Up-conversion Luminescence of Er~(3+)-Doped PMN-PT Transparent Ceramics

摘要

The non-doped and 0.5, 1.0, 2.0, and 5.0 mol% Er~(3+)-doped 0.75Pb(Mg_(1/3)Nb_(2/3))O3-0.25PbTiO_3 (called PMN-PT) transparent ceramics have been fabricated. The optical absorption spectra, photoluminescence excitation and emission spectra, and the up-conversion luminescence spectra under the excitation of 980 nm laser were investigated. The up-conversion luminescence of Er~(3+)-doped PMN-PT transparent ceramics changes from yellowish green to reddish orange with increasing the Er~(3+) doping concentration. The dependence of visible up-conversion luminescence on the laser power was measured. The up-conversion luminescence saturation is observed for Er~(3+) 5.0 mol%-doped PMN-PT. A possible up-conversion luminescence mechanism is proposed, which depends on Er~(3+) concentration. The up-conversion emission is mainly due to excited state absorption for lightly Er~(3+)-doped PMN-PT transparent ceramics, while the energy-transfer processes are for highly doped ones.