Photo-/cathodoluminescence and energy transfer properties of novel Ce3+ singly doped and Ce3+/Tb3+ codoped NaBaScSi2O7 phosphors

Abstract

A series of novel Ce³⁺ singly doped and Ce³⁺/Tb³⁺ codoped color-tunable NaBaScSi₂O₇ phosphors were synthesized via the solid state method. The morphology, UV-vis reflectance, photoluminescence emission and excitation spectra, the lifetime and the thermal quenching properties were investigated in detail. NaBaScSi₂O₇:Ce³⁺ phosphors showed intense blue emission at about 425 nm, corresponding to the transitions from the lowest 5d excited state to the ²F_5/2 and ²F_7/2 spin orbit 4f ground states of Ce³⁺ ions, under optimal excitation of 349 nm. Under excitation of Ce³⁺ ions at 349 nm, the emission spectra of NaBaScSi₂O₇:Ce³⁺,Tb³⁺ phosphors consisted of a blue emission band of Ce³⁺ ions at 425 nm and a series of strong green emission lines at 488, 542, 582, and 625 nm due to the ⁵D₄ → ⁷F_J (J = 6, 5, 4, and 3) characteristic transitions of Tb³⁺ ions. A possible energy transfer mechanism was proposed and ascribed to the dipole–dipole interaction on the basis of the experimental results and analysis. In addition, the cathodoluminescence properties of NaBaScSi₂O₇:Ce³⁺,Tb³⁺ were also studied in detail. The current results indicate that NaBaScSi₂O₇:Ce³⁺,Tb³⁺ can serve as a potential phosphor for application in UV-WLEDs and FEDs.