Cyan-emitting Ca2YHf2Al3O12:xCe3+ garnet phosphors with a high photoluminescence quantum efficiency of up to 89.5% were developed for fabricating high color rendering warm-white LEDs.

In this Letter, we report a novel NaLaMgWO:Mn double-perovskite phosphor. Under the excitation at 342 nm, this phosphor showed a high-efficiency far-red emission at approximately 700 nm with internal quantum efficiency of up to 60%. Moreover, it exhibited a high thermal stability; the emission intensity at 423 k was approximately 57% of that at room temperature. Finally, a prototype light-emitting diode (LED) device was fabricated using the combination of a NaLaMgWO:Mn far-red-emitting phosphor and 365-nm LED chip.

Broadband cyan-emitting Ca2LuZr2(AlO4)3:Ce3+ garnet phosphors enabled to fill the cyan gap in the emission spectra of near-ultraviolet-pumped warm-white LEDs, thus resulting in improved color rendering index.

Novel near-UV-excitable Ca2YHf2Al3O12:Ce3+,Tb3+ green phosphors with a highest internal quantum efficiency of 86.6% and external quantum efficiency of 63.1% were reported for high-CRI warm-white LEDs.

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