RE ³⁺ : La ₂ CaB ₁₀ O ₁₉ (RE = Dy, Eu) single crystals: advanced phosphors for applications in white LEDs/LDs

The current commercial blue InGaN chip white light-emitting diodes (LEDs) and RGB (red, green, and blue) full-color white LEDs based on yellow-emitting phosphors are insufficient for increasing requirements of future solid-state lighting applications. In this work, Dy³⁺ and Eu³⁺ doped La₂CaB₁₀O₁₉ (LCB) single crystals were successfully grown by the top-seeded solution growth method. Their physical properties as phosphors for high-efficiency white LEDs and laser diodes (LDs) were systematically investigated. It was found that the Dy: LCB and Eu: LCB crystal-based phosphors can emit stable white light by the combination of stimulated emissions and residual incident excitation light. Notably, the correlated color temperature (CCT) of the white light can be effectively tuned by modulating the doping concentration of rare-earth (RE) ions. A wide CCT range of 1,800 to 10,000 K was achieved, with fluorescence quantum yield (FQY) of 61.47%. Considering their stable physical properties and high laser-induced damage threshold (LIDT), RE-doped LCB single crystals demonstrate considerable potential as excellent candidates for luminescent materials, particularly suited for applications in high-power white LEDs and LDs.