Spectroscopic properties of cerium-doped aluminosilicate glasses

Abstract

The spectroscopic properties of cerium ions in various aluminosilicate glasses modified by Mg2+, Ca2+, Ba2+ and Na+ were investigated in order to optimize these for the potential utilization as Ce3+/Yb3+ quantum cutting material. An increasing optical basicity of the glasses results in a shift in the peak position of the 5d-4f emission of Ce3+ to longer wavelengths and in a decrease in the Ce3+ fluorescence intensity due to decreasing Ce3+/Ce4+ ratios. Argon-bubbling of the melt and supplying argon as melting atmosphere and/or using small amounts of metallic aluminum powder as raw material led to an almost complete reduction of Ce4+ to Ce3+. This resulted in much higher intensities of the Ce3+ fluorescence emission which runs parallel to a decreasing charge transfer absorption of Ce4+. From the absorption spectra of these samples extinction coefficients for Ce4+ and Ce3+ were calculated. For this purpose, an additional sample was prepared by using oxygen bubbling of the melt. An increasing cerium concentration shifts the Ce3+ emission peak position to longer wavelengths, while up to 2·1020 ions per cm3 only a slight increase in the Ce3+ emission intensity was observed. At higher dopant concentrations, a drastic decrease in the Ce3+ fluorescence emission is observed which is most likely attributed to an increasing Ce4+ concentration. High intensity Ce3+ blue emission matching the spectroscopic requirements for potential quantum cutting in Ce3+/Yb3+ codoped glasses could be achieved with a barium aluminosilicate glass.