Energy transfer processes in Ca3Tb2−xEuxSi3O12 (x = 0–2)

• Ca3Tb2−xEuxSi3O12 (x = 0–2) phosphors have been synthesized via solid state reaction.
• The luminescent properties of the phosphors have been studied upon UV excitation.
• Fast energy migration among Tb3+ ions has been found.
• Tb3+–Eu3+ energy transfer is observed upon excitation into Tb3+.
• The transfer produces strong emission from Eu3+ in the red spectral region.

The luminescent properties of Tb3+ and Eu3+ have been studied in several silicates having a silico-carnotite-type structure. Fast energy migration among Tb3+ ions has been found in Ca3Tb2Si3O12 and Ca3Tb2–xEuxSi3O12 (x = 0–0.1). In the case of Ca3Tb2–xEuxSi3O12, Tb3+–Eu3+ energy transfer is observed upon excitation in the UV bands of Tb3+. The transfer gives rise to strong emission from Eu3+ in the red spectral region at 612 nm. The efficiency of the transfer at room temperature in Ca3Tb1.9Eu0.1Si3O12 has been evaluated. The temperature evolution of the luminescent properties of Ca3Tb2Si3O12 and Ca3Tb1.9Eu0.1Si3O12 has been studied at temperatures ranging from 8 to 330 K.