Compositional dependence of upconversion luminescence of trivalent erbium ions in fluorozirconate glasses II. Alkaline earth fluoride dependence

Abstract

In order to inquire a possibility of compositional designing for the upconversion luminescence of Er 3+ in ZrF 4-based glasses, the glass-modifying alkaline earth-fluoride dependence of emission characteristic was investigated using glasses 5MF 2·25BaF 2·65ZrF 4·5ErF 3 (M=Mg, Ca, Sr or Ba). Upconversion luminescence of the glasses by 800nm excitation gave emission bands around 410, 525, 550 and 660nm. The intensities of the respective emission bands largely changed, depending on the alkaline-earth fluoride species, MF 2. Analyses of the fluorescence and excitation spectra of Eu 3+-substituted glasses clarified that the MF 2 dependence of upconversion emission intensity in the 5MF 2·25BaF 2·65ZrF 4·5ErF 3 glasses is determined by both the deviation from inversion symmetry in the F − coordination around Er 3+ and the phonon energy of glass. The present study concludes that the upconversion luminescence of Er 3+ in ZrF 4-based glasses may be designed by choosing and/or combining suitable glass-modifying alkaline-earth fluorides.