Energy Transfer and Defects Study in ${\rm Ce}^{3+}$ , ${\rm \Pr}^{3+}$ Co-doped

Lu₂Si₂O₇ (LPS) single crystals doped with 0.05%Ce and co-doped with 0.05%Ce, 0.05%Pr were grown by floating zone method. The segregation coefficients of Pr and Ce in LPS host were estimated through ICP-OES method. The VUV-UV excitation and emission spectra at 150 K, X-ray excited luminescence, fluorescence decay time of Ce³⁺ emission at room temperature and thermally stimulated luminescence (TSL) spectra of LPS:Ce and LPS:Ce,Pr were measured. The energy transfer from Pr³⁺ to Ce³⁺ in LPS host was observed through the VUV-UV spectra and possible transfer pathways are discussed. The luminescence intensity of Ce³⁺ can be improved by about 20% after Pr³⁺ co-doping. Defects in LPS host are studied through TSL spectra.