Fluorescence property investigations on Er~(3+)-doped oxyfluoride glass ceramics containing LaF_3 nanocrystals

摘要

The fluorescence properties of oxyfluoride glass ceramics containing nanosized LaF_3 crystals with different ErF_3 doping level were investigated. The spectroscopy analysis indicated that a dominant fraction of ErF_3 had been incorporated into the crystal phase. Broad 1.5 μm emission spectra with full width at half maximum (FWHM) value ranging from about 40-100 nm were obtained, which increased accordingly with ErF_3 doping level. Noteworthily, intense green and red upconversion emissions from samples with high ErF_3 doping level were observed when excited even with a 30 mW diode laser at 976 nm. An overall increment of the upconversion emissions intensity, and, a relative increase in intensity of the red emission with respect to that of the green one were also identified with increasing ErF_3 concentration. The possible upconversion mechanisms were proposed.