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

Abstract

We have synthesized the pure ternary nitride phosphor, LaSi 3 N 5 : Ce 3 + from the multicomponent oxide system La 2 O 3 – CeO 2 – SiO 2 , by using the gas-reduction-nitridation method. Highly pure, single-phase LaSi 3 N 5 : Ce 3 + powders possessing particle sizes of ∼ 0.4 – 0.6 μ m were obtained with the processing temperature ≤ 1500 ° C . The synthesized LaSi 3 N 5 : Ce 3 + 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 LaSi 3 N 5 : Ce 3 + 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.