title: Improvement of the Water Resistance of a Narrow-Band Red-Emitting SrLiAl3 N4 :Eu(2+) Phosphor Synthesized under High Isostatic Pressure through Coating with an Organosilica Layer.
abstract: A SrLiAl3 N4 :Eu(2+) (SLA) red phosphor prepared through a high-pressure solid-state reaction was coated with an organosilica layer with a thickness of 400-600 nm to improve its water resistance. The observed 4f(6) 5d→4f(7) transition bands are thought to result from the existence of Eu(2+) at two different Sr(2+) sites. Luminescence spectra at 10 K revealed two zero-phonon lines at 15377 (for Eu(Sr1)) and 15780 cm(-1) (for Eu(Sr2)). The phosphor exhibited stable red emission under high pressure up to 312 kbar. The configurational coordinate diagram gave a theoretical explanation for the Eu(2+/3+) result. The coated samples showed excellent moisture resistance while retaining an external quantum efficiency (EQE) of 70 % of their initial EQE after aging for 5 days under harsh conditions. White-light-emitting diodes of the SLA red phosphor and a commercial Y3 Al5 O12 :Ce(3+) yellow phosphor on a blue InGaN chip showed high color rendition (CRI=89, R9=69) and a low correlated color temperature of 2406 K.
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan.
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Tsai
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan.|Institute of Applied Materials Science, Vietnam Academy of Science and Technology, Hochiminh City, 700000, Vietnam.
authors.forename: Hoang-Duy
authors.initials: HD
authors.lastname: Nguyen
authors.affiliation: Institute of Experimental Physics, University of Gdansk, Wita Stwosza 57, 80-952, Gdansk, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Lazarowska
authors.affiliation: Institute of Experimental Physics, University of Gdansk, Wita Stwosza 57, 80-952, Gdansk, Poland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Mahlik
authors.affiliation: Institute of Experimental Physics, University of Gdansk, Wita Stwosza 57, 80-952, Gdansk, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Grinberg
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan. rsliu@ntu.edu.tw.|Department of Mechanical Engineering and Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 106, Taiwan. rsliu@ntu.edu.tw.
authors.forename: Ru-Shi
authors.initials: RS
authors.lastname: Liu
keywords: charge transfer; coatings; light-emitting diodes; luminescence; phosphors