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A series of well-dispersed (Ce 1- x Tb x)PO 4 (x = 0–1) microspheres, with an average diameter of ∼1.2 μm, have been originally prepared via two-phase interfacial precipitation and subsequent calcination. Characteristics of the as-synthesized and calcination products were investigated by the combined techniques of XRD, FE-SEM, TEM, FT-IR and TG-DSC. Under 275 nm excitation, tuning the emission color from blue (0.17, 0.02) to green (0.30, 0.56) was realized via varying the Tb3+ content and through Ce3+ → Tb3+ energy transfer. The optimal content of Tb3+ was found to be ∼15 at% (x = 0.15), and the energy transfer was determined to occur via electric dipole-dipole interaction. Moreover, both the emissions of Ce3+ and Tb3+ present gradually higher thermal stability with increasing Tb3+ content owing to enhanced energy transfer. The (Ce 0.85 Tb 0.15)PO 4 microspheres, which possess the highest absolute quantum efficiency (∼60.1%) across the series and excellent thermal stability (activation energy for thermal quenching of luminescence: ∼0.312 eV), may potentially serve as a single-phase green phosphor for solid-state lighting and field-emission display. Multi-color luminescent (Ce 1- x Tb x)PO 4 (x = 0–1) microspheres were successfully fabricated via gel/solution interfacial precipitation and subsequent calcination. Image 1 • (Ce 1- x Tb x)PO 4 (x = 0–1) microspheres were obtained via interfacial precipitation. • The formation mechanism of (Ce 1- x Tb x)PO 4 spheres was proposed. • Ce3+.→ Tb3+ energy transfer was analyzed to occur via dipole-dipole interaction • (Ce 0.85 Tb 0.15)PO 4 has favorable thermal stability for Tb3+ luminescence. [ABSTRACT FROM AUTHOR]

A series of garnet-type Li 6 CaLa 2(1- x) Nb 2 O 12 : x RE phosphors (LCLN: x RE, RE = Pr, Sm, Tb and Dy) were prepared via sol-gel processing and subsequent calcination for the first time, with the course of phase evolution and the characteristics of the LCLN host and RE3+ luminescence being investigated in detail. It was found that ∼900–1000 °C is a suitable temperature for precursor calcination to produce the garnet phase and LCLN has a relatively low phonon energy (∼725 cm−1) and a relatively wide bandgap (∼4.53 eV) for luminescence. The LCLN:0.012Pr, LCLN:0.04Sm, LCLN:0.06 Tb and LCLN:0.06Dy typical phosphors were analyzed to have dominant excitation/emission bands at ∼278/489, 265/614, 268/549 and 264/581 nm, emission colors of white, orange, green and yellowish white, and fluorescence lifetimes of ∼0.43, 0.74, 0.90 and 0.44 ms, respectively. Temperature-dependent photoluminescence found that the four phosphors maintained ∼28, 37, 45 and 56% of their room-temperature intensities at 423 K, with activation energies for thermal quenching of ∼0.37, 0.29, 0.34 and 0.25 eV, respectively. The results demonstrated that the Li-stuffed LCLN garnet could be a suitable host for UV excitable multicolor phosphors. • ∼900–1000 °C is an appropriate temperature for precursor calcination to derive Li 6 CaLa 2 Nb 2 O 12 (LCLN) garnet. • The LCLN host is suitable for luminescence purposes. • The photoluminescence of Pr3+, Sm3+, Tb3+ and Dy3+ activators was comprehensively elaborated in LCLN. • The concentration quenching of Sm3+ luminescence in LCLN is dominantly resulted from electric dipole-dipole interaction. [ABSTRACT FROM AUTHOR]