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Feasible preparation of red‐phosphor K 2 SiF 6 :Mn 4+ coated with SiO 2 for white light emitting diodes application
Author(s) -
Quan Vu Thi Hong,
Tuyet Doan Thi,
Dereń Przemysław J.,
Hieu Nguyen Pham Trung,
Duy Nguyen Hoang
Publication year - 2019
Publication title -
vietnam journal of chemistry
Language(s) - English
Resource type - Journals
eISSN - 2572-8288
pISSN - 0866-7144
DOI - 10.1002/vjch.201960029
Subject(s) - phosphor , tetraethyl orthosilicate , materials science , orthosilicate , thermal stability , analytical chemistry (journal) , photoluminescence , quantum yield , transmission electron microscopy , diode , coating , optoelectronics , chemical engineering , optics , chemistry , nanotechnology , fluorescence , chromatography , physics , engineering
We report a facile approach for coating K 2 SiF 6 :Mn 4+ red‐phosphor with a moisture‐resistant silica layervia the one‐step co‐precipitation using tetraethyl orthosilicate (TEOS) and sodium dodecyl benzene sulphonate (SDBS) surfactant. The bare K 2 SiF 6 :Mn 4+ (KSF) phosphor with nearly round‐shape and 10 μm diameter, showed a high external quantum yield ~0.502 under 460 nm light excitation. The 40 nm‐ and 80 nm‐thick SiO 2 coatinglayers on the phosphor surface was observed via transmission electron microscopy (TEM). The K 2 SiF 6 :Mn 4+ coated with SiO 2 (KSF@SiO 2 ) phosphor possesses bright red emission at approximately 630 nm, high thermal stability and excellent waterproof. Effect of coating layer‐thickness on photoluminescence properties of the prepared phosphors have been investigated and discussion.