Consequences of Ca Codoping in YAlO3:Ce Single Crystals

The influence of Ca codoping on the optical absorption, photo-, radio-, and thermo-luminescence properties of YAlO3:Ce (YAP:Ce) crystals has been studied for four different calcium concentrations from 0 to 500 ppm. Ca cooping results in partial oxidation of Ce3+ into Ce4+.The luminescence time response under pulsed X-ray excitation of the Ce3+/Ce4+ admixture clearly demonstrates the role of hole migration on both the rise time and the generally observed slow components. From an application point of view, Ca-codoping significantly improves the timing performances but the induced presence of Ce4+ ions is also the cause of a reduction in scintillation efficiency