Design and realization on orange-red emitting of samarium activated sodium lanthanum metaphosphate with low CCT and high CP

To promote the development of the solid state lighting and display industry, exploring excellent inorganic phosphors has been always a hot scientific and applied issue. Herein, we have constructed series of samarium activated sodium lanthanum metaphosphate NaLaP4O12 (abbreviated as: NLP) phosphors via the high-temperature solid phase synthesis process. The crystalline phase composition, micromorphology, ionic valence states, diffuse reflectance absorption performance and concentration quenching mechanism were solved in detail. The photoluminescence excitation (PLE) and photoluminescence (PL) behavior of the as-prepared samples is closely dependent on the doping Sm3+ concentration. The optimized PL strategy is as following: the strongest excitation line is located at 401 nm, and the optimal doping concentration is 7 mol%. NLP:7%Sm3+ displays intense orange-red visible luminescence with the dominant (4)G(5/2 )-> H-6(7/2) transitions located at 596 and 605 nm. The detailed investigation on CIE chromaticity coordinates, color purity (CP), correlated color temperature (CCT), internal quantum efficiency (IQE) and fluorescence lifetime suggests that we may use NLP:Sm3+ micropowder as alternative ingredient for phosphor-converted near UV-based warm white LEDs. (C) 2019 Elsevier B.V. All rights reserved.