High Charge Carrier Storage Capacity in Lithium Lutetium Silicate Doped with Cerium and Thulium

It is demonstrate that LiLuSiO4:Ce,Tm has excellent charge carrier storage properties. Comparative studies are performed with the state-of-the art X-ray storage phosphor BaFBr(I):Eu. The thermoluminescence (TL) intensity of the optimized LiLuSiO4:Ce,Tm is four times higher than the TL of BaFBr(I):Eu. After 3 h of storage at room temperature (RT) there is still 94% of initial thermoluminescence and only 48% for BaFBr(I):Eu which demonstrates insignificant thermal fading. The signal can be read out by a blue LED and less efficiently by a red laser. It does require higher stimulation energy than in the case of BaFBr(I):Eu. The self-irradiation with a dose rate of 13 mu Gy h(-1) due to Lu-176 isotopes is not a serious drawback for application.