Premium
Optimized photoluminescence of red phosphor Na 2 SnF 6 :Mn 4+ as red phosphor in the application in “warm” white LED s
Author(s) -
Xi Luqing,
Pan Yuexiao,
Chen Xian,
Huang Shaoming,
Wu Mingmei
Publication year - 2017
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.14708
Subject(s) - phosphor , luminescence , photoluminescence , analytical chemistry (journal) , doping , crystallinity , color temperature , color rendering index , materials science , chemistry , mineralogy , crystallography , optoelectronics , chromatography
The Mn 4+ activated fluostannate Na 2 SnF 6 red phosphor was synthesized from starting materials metallic tin shots, NaF, and K 2 MnF 6 in HF solution at room temperature by a two‐step method. The formation mechanism responsible for preparing Na 2 SnF 6 :Mn 4+ ( NSF :Mn) has been investigated. The influences of synthetic parameters: such as concentrations of HF and K 2 MnF 6 in reaction system, reaction time, and temperature on crystallinity, microstructure, and luminescence intensity of NSF :Mn have been investigated based on detailed experimental results. The actual doping concentration of Mn 4+ in the NSF :Mn host lattice is less than 0.12 mol%. The most of K 2 MnF 6 is decomposed in HF solution especially in hydrothermal system at elevated temperatures. The color of the as‐prepared NSF :Mn samples changes from orange to white when the temperature is higher than 120°C, which indicates the lower concentration of luminescence centers in the crystals. A series of “warm” white light‐emitting diodes with color rendering index ( CRI ) higher than 88 and correlated color temperatures between 3146 and 5172 K were obtained by encapsulating the as‐prepared red phosphors NSF :Mn with yellow one Y 3 Al 5 O 12 :Ce 3+ ( YAG :Ce) on 450 nm blue InGaN chips. The advantage of the synthetic strategy to obtain NSF :Mn can be extended to developing Mn 4+ ‐doped red phosphors from low‐costing metals at room temperature for large‐scale industrial applications.