Investigation of the Effect of Gd3+ on Host-to-Europium Transfer Efficiency in (Y,Gd)BO3:Eu3+ Under VUV Excitation

Using reflectance and excitation spectroscopy, host-to-Eu3+ energy transfer efficiencies in YBO3:Gd,Eu under vacuum ultraviolet excitation have been calculated, at various concentrations of both dopants. As the Gd3+ concentration is increased, an increase in the transfer efficiency to Eu3+ is observed, consistent with prior spectroscopic studies. The role of Gd3+ in these materials is discussed quantitatively in terms of alpha/beta ratios calculated from fits of the transfer efficiency data using accepted kinetic models. Some increase in the effective electron-hole mobility and capture by Eu3+ is observed at 5 mol % Gd3+, and extremely efficient energy migration is observed by 30 mol % Gd3+.