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-Eu 3+ energy transfer efficiencies in YBO 3:Gd,Eu under vacuum ultraviolet excitation have been calculated, at various concentrations of both dopants. As the Gd 3+ concentration is increased, an increase in the transfer efficiency to Eu 3+ is observed, consistent with prior spectroscopic studies. The role of Gd 3+ in these materials is discussed quantitatively in terms of α/β ratios calculated from fits of the transfer efficiency data using accepted kinetic models. Some increase in the effective electron−hole mobility and capture by Eu 3+ is observed at 5 mol % Gd 3+, and extremely efficient energy migration is observed by 30 mol % Gd 3+ .