NIR to Visible Up‐conversion Luminescence of Er3+‐Doped PMN‐PT Transparent Ceramics
The non‐doped and 0.5, 1.0, 2.0, and 5.0 mol% Er3+‐doped 0.75Pb(Mg1/3Nb2/3)O3‐0.25PbTiO3
(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 Er3+‐doped PMN‐PT transparent ceramics changes from yellowish green to reddish orange with increasing the Er3+ doping concentration.
The dependence of visible up‐conversion luminescence on the laser power was measured. The up‐conversion luminescence saturation is observed for Er3+ 5.0 mol%‐doped PMN‐PT.
A possible up‐conversion luminescence mechanism is proposed, which depends on Er3+ concentration. The up‐conversion emission is mainly due to excited state absorption for lightly Er3+‐doped
PMN‐PT transparent ceramics, while the energy‐transfer processes are for highly doped ones.