Phosphors of Rb3La1−xTbxSi2O7 with K3NdSi2O7-type Structure

Green-emitting phosphors of Rb3La1−xTbxSi2O7 with a K3NdSi2O7-type structure were synthesized via a solid-state reaction technique. Their crystal structures and photoluminescence properties were investigated. Crystal structural analyses of Rb3LaSi2O7 and Rb3TbSi2O7 were carried out for the first time and revealed that the rare-earth sites (La or Tb) were separated by the RbO6 and SiO4 units. According to photoluminescence spectroscopy of Rb3La1−xTbxSi2O7 monitored at 249 and 481 nm, the highest emission intensity was obtained for the Rb3TbSi2O7 phosphor under the 481-nm excitation, which indicates that the satisfactory separation of the Tb3+ ions suppressed the concentration quenching. The intensity of Rb3TbSi2O7 was 32 % in comparison to that of the commercial green-emitting (La0.52Ce0.31Tb0.17)PO4 phosphor.