Impact of co-doping on scintillation properties of Lu2xGd2(1−x)SiO5:Ce (LGSO, x=0.9)

Lu_2xGd_2(1-x)SiO₅:Ce single crystal scintillators (LGSO) with higher Lu content (x=0.9) providing by Hitachi Chemical has been attractive for PET (Positron Emission Tomography) detector in its remarkable scintillation properties. We reported the scintillation properties of LGSO:Ce doped with tetra, penta and hexa-valent elements, which could be expected to improve the performance as in the case of Zr co-doped GSO:Ce. But the fact that the LGSO:Ce showed results that are different from GSO and LSO. We further investigated the influence of some tri-valent elements (Al, Ga) co-doped with Ce on scintillation properties excited by Gamma-ray, UV and X-ray. A small amount of the tri-valent elements has small impacts on the light output and reduce the defects measured by thermoluminescence (TL) glow curves, but a large amount of the tri-valent elements diminished the light output and made energy resolution worse significantly with the energy spectrum of non-Gaussian shape.