Blue-emitting LaSi3N5:Ce3+ fine powder phosphor for UV-converting white light-emitting diodes

Abstract

We have synthesized the pure ternary nitride phosphor, LaSi3N5:Ce3+ from the multicomponent oxide system La2O3–CeO2–SiO2, by using the gas-reduction-nitridation method. Highly pure, single-phase LaSi3N5:Ce3+ powders possessing particle sizes of ∼0.4–0.6 μm were obtained with the processing temperature ≤1500 °C. The synthesized LaSi3N5:Ce3+ exhibits tunable blue broadband emission with the dominant wavelength of 464–475 nm and the external quantum efficiency of ∼34%–67% under excitation of 355–380 nm. A high thermal stability of LaSi3N5:Ce3+ compared to the existing La–Si–O–N hosts was demonstrated, indicating the promising applicability as a blue-emitting phosphor for UV-converting white light-emitting diodes.