Optical properties and energy transfers of Ce3+ and Mn2+ in Ba9Sc2(SiO4)6

Analysis of XRD patterns indicates that Ce3+ and Mn2+ in Ba9Sc2(SiO4)6 (BSS) presents preferably at the Sc3+ and the Ba2+ site, respectively. Ba9Sc2(SiO4)6:Ce3+ (BSS:Ce3+) exhibits an intense emission band peaked at 383 nm. Codoping Mn2+ into this material can generate a red emission band at 615 nm of Mn2+ through Ce3+-Mn2+ energy transfers (ETs). To achieve the ET mechanisms, critical distance and coefficient, the dynamical processes of the ET are investigated based on Inokuti-Hirayama model. For Ce3+ concentration of 5 mol%, the corresponding rate constant and the critical distance are evaluated to be 8.4×10−37 cm6 s−1 and 0.52 nm, respectively. The ET efficiency can reach 48%. The emission intensity ratio of the Mn2+ to the Ce3+ is also studied to understand color-tunable luminescence as the blue Ce3+ is excited by UV light. These results show the promising application of this phosphor for white LEDs.