LAUSR

Abstract Two efficient approaches based on cross-relaxation and non-steady-state upconversion processes were used to regulate the upconversion emission colors of Er 3+ in Gd 2 O 3 host, in which the cross-relaxation induced tunable up-conversion color of Er 3+ was implemented via adjusting the doping concentration of Er 3+ and co-doping Tm 3+ and Ho 3+ . The corresponding energy transfer mechanism was elaborately investigated through down-conversion emission spectra and decay lifetimes. In addition, the influences of the excitation pulse-width of 980 nm laser on up-conversion emission color of Er 3+ were also investigated on the basis of non-steady-state up-conversion processes. Results provide new insights into the influence of cross-relaxation and non-steady-state processes on the up-conversion luminescence, which endows up-conversion phosphor with the more opportunities to satisfy diverse applications by controlling its color output.