Efficient broadband green-emitting Ca2LuScGaAlSi2O12:Ce3+ garnet phosphor towards high-color-rendering full-spectrum WLED lighting

To achieve high-performance white light emitting diodes (WLEDs) lighting, broadband green phosphors are still considered key materials. In this study, we successfully synthesized a series of efficient Ca₂Lu_1-xScGaAlSi₂O₁₂:xCe³⁺ (CLS:xCe³⁺) garnet-type phosphors with broadband green emission (peak centered at 525 nm; full width at half maximum, FWHM = 106 nm). The CLS:xCe³⁺ green phosphors are well suited for use in blue-pumped WLEDs due to their optimal excitation wavelength of 452 nm. The crystal structure, electronic structure, band structure, activator occupancy and photoluminescence properties of the CLS:xCe³⁺ phosphors were systematically investigated. The optimal CLS:0.04Ce³⁺ sample exhibits good thermal stability (57%@423 K), outstanding color stability (ΔE = 3.50 × 10⁻³ at 423 K) and a high internal quantum efficiency (IQE = 70%). Moreover, by integrating the green phosphor CLS:0.04Ce³⁺ and commercial red phosphor CaAlSiN₃:Eu²⁺ with a 450 nm LED chip, a high-performance prototypical WLED can emit full-spectrum warm white light with high color rendering index (CRI = 94) and relatively low correlated color temperature (CCT = 4508 K). The results indicate that the reported Ca₂LuScGaAlSi₂O₁₂:Ce³⁺ green garnet phosphor exhibits significant potential as a next-generation green-emitting material for high-performance full-spectrum WLED lighting.