Light Emission Mechanism of Lu2(Si04)0:Ce

Lutetium oxyorthosilicate Lu2( S iO4)O has two crystallographically independent lutetium sites. When it is doped with Ce, the dopant Ce is assumed to occupy two different sites and thus the existence of two activation centers (called “Cel” and “Ce2”) was proposed. UV and gamma-ray excited spectra clearly indicate that two activation centers exist in cerium-doped lutetium oxyorthosilicate Lu2(Si04)0:Ce &SO). REz(SiO4)O. it is reasonable to assume that there are also two Ce+3 sites in RE2(Si04)0:Ce. In fact, our previous study [6] revealed that Ce-doped gadolinium oxyorthosilicate Gdz(SiO4)O:Ce (GSO), which has the p21/c structure type, has two Ce sites and that these two activation centers contribute to the emission excited by gamma-ray radiation. Although LSO has a different structure (C2/c) than GSO (P21/c), it also has two crystallographically independent lutetium sites. Thus it is natural to assume that there are also two Ce+3 sites, i.e., two activation centers in LSO. The twoactivation-center model has been investigated for its applicability in describing the scintillation mechanism in LSO.