Green and red upconversion luminescence in CeO 2:Er 3+ powders produced by 785 nm laser

Abstract

CeO 2:Er 3+ powders were prepared by Pechini type sol–gel method. The structural properties of CeO 2:Er 3+ were studied by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectra. The results show that CeO 2:Er 3+ has low phonon cutoff energy, which indicate that CeO 2:Er 3+ may have high luminescent efficiency. The green and red upconverted luminescence spectra of Er 3+ were investigated under excitation into the 4 I 9/2 level by 785 nm laser. The upconversion mechanisms were studied in detail through laser power dependence and Er 3+ ions concentration dependence of upconverted emissions, and results show that excited state absorption and energy transfer process are the possible mechanisms for the upconversion. The upconversion properties indicate that CeO 2:Er 3+ may be used in upconversion phosphors.