Effect of Tb3+ concentration on luminescence properties of Ce/Tb/Eu co-doped borosilicate glasses for white LEDs

Abstract

Ce, Tb and Eu single and ternary doped borosilicate glasses were prepared and effect of Tb3+ concentration on luminescence properties of ternary co-doped glasses were analyzed by utilizing emission spectra, excitation spectra, the Commission International de I’Eclairage (CIE) colorimetric system and fluorescence decay curves. The results show that Tb3+ concentration significantly affects spectral intensities of ternary co-doped glasses when excited by near ultraviolet (NUV). With the increasing of Tb3+ concentration, the blue emission of Ce3+ is weakened and the red emission of Eu3+ is slightly enhanced. Both the color coordinates and correlated color temperatures (CCTs) can be adjusted by Tb3+ concentration. Besides, the energy transfers from Ce3+ to Tb3+ and from Tb3+ to Eu3+ were observed. Measured characteristic lifetimes of Tb3+ indicate that the energy transfer from Ce3+ to Tb3+ tends to predominate in whole process. The studies show that Ce/Tb/Eu ternary doped borosilicate glasses might be promising luminescence materials for NUV pumped white LEDs.