Green and red upconversion luminescence in CeO2:Er3+ powders produced by 785 nm laser

CeO2:Er3+ powders were prepared by Pechini type sol–gel method. The structural properties of CeO2:Er3+ were studied by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectra. The results show that CeO2:Er3+ has low phonon cutoff energy, which indicate that CeO2:Er3+ may have high luminescent efficiency. The green and red upconverted luminescence spectra of Er3+ were investigated under excitation into the 4I9/2 level by 785 nm laser. The upconversion mechanisms were studied in detail through laser power dependence and Er3+ 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 CeO2:Er3+ may be used in upconversion phosphors.