Synthesis and photoluminescent properties of (La,Ca)₃Si₆N₁₁:Ce³+ fine powder phosphors for solid-state lighting

We have developed a new Ce(3+)-activated nitride phosphor, (La,Ca)(3)Si(6)N(11):Ce(3+), using the gas-reduction-nitridation method. The synthesized (La,Ca)(3)Si(6)N(11):Ce(3+) possesses tunable yellow broadband emission with the dominant wavelength of 577-581 nm and the external quantum efficiency up to ∼42%, under an excitation of 450 nm. Precise steady-state and time-resolved photoluminescence analyses revealed that the only one type of Ce(3+) center is active under the blue-light excitation. By combining the synthesized (La,Ca)(3)Si(6)N(11):Ce(3+) phosphors with the 450-nm InGaN chip, a broad range of white light with the correlated color temperatures of ∼2600-3800 K can be created, demonstrating their promising applicability to the warm-white light-emitting diodes.