The photoluminescence, thermal properties and tunable color of bright green-emitting Ba3Sc(BO3)3:Ce3+/Tb3+ phosphors via efficient energy transfer

Highlights: • Ce³⁺ ions occupied at Ba and Sc³⁺ sites for Ba₃Sc(BO₃)₃:Ce³⁺ emit blue light. • Broader absorption band (200–400 nm) matches well with the n-UV LED chips. • Decay curves prove the existence of multiple sites energy transfer of Ce³⁺.→Tb³⁺. • Color tuning from blue to green is successfully realized by the energy transfer. • Luminous intensity and thermal stability are increase. -- Abstract: The single-phase Ba₃Sc(BO₃)₃:Ce³⁺/Tb³⁺ samples were synthetized via high-temperature solid-state reaction. X-ray diffraction (XRD), Rietveld refinement and transmission electron microscopy (TEM) were used for characterizing the morphology and phase purity of Ba₃Sc(BO₃)₃. The photoluminescence emission (PL) and excitation (PLE) spectra, lifetime decay behavior and thermal stability of the Ba₃Sc(BO₃)₃:Ce³⁺/Tb³⁺ phosphors were discussed in detail. Site occupation of Ce³⁺ ions in Ba²⁺ and Sc³⁺ sites were explained through Gaussian fitting and Van Uitert empirical equation. All these properties are closely related to the intrinsic crystallization structure of the Ba₃Sc(BO₃)₃ matrix, which is discussed in detail in this paper. Compared with Ba₃Sc(BO₃)₃:1%Tb³⁺ sample, the luminous intensity of Tb³⁺ increased about 3.2 and 4.1 times for Ba₃Sc(BO₃)₃:2%Ce³⁺,1%Tb³⁺ monitored at 342 and 313 nm, respectively. Energy transfer (ET) mechanism of Ce³⁺→Tb³⁺ were dipole-dipole interactions and quadrupole-quadrupole interactions at Ce³⁺(1) and Ce³⁺(2) sites, respectively. The temperature-dependent PL spectra of Ba₃Sc(BO₃)₃: Ce³⁺,Tb³⁺ illustrated that this phosphor possesses excellent thermal stability and chromaticity stability. Finally, a white LED device was prepared via the combination of the n-UV chip (365 nm), commercial blue BAM:Eu²⁺ phosphor, green Ba₃Sc(BO₃)₃:2%Ce³⁺,6%Tb³⁺ phosphor and commercial red Sr₂Si₅N₈:Eu²⁺ phosphor, which showed bright warm-white light. These conclusions proved that the green Ba₃Sc(BO₃)₃:2%Ce³⁺,6%Tb³⁺ phosphor is desirable for white LED applications.