TY - JOUR
T1 - Improved phase stability of the metastable K2GeF6:Mn4+ phosphors with high thermal stability and water-proof property by cation substitution
AU - Lang, Tianchun
AU - Han, Tao
AU - Fang, Shuangqiang
AU - Wang, J.
AU - Cao, Shixiu
AU - Peng, Lingling
AU - Liu, B.
AU - Korepanov, Vladimir I.
AU - Yakovlev, Aleksey N.
PY - 2020/1/15
Y1 - 2020/1/15
N2 - K2GeF6:Mn4+ (KGFM) phosphors with very poor water-proof property in HF solution transform automatically from P63mc hexagonal phase to P3¯m1 trigonal phase. By substituting Ge4+ ion with Si4+ ion, the metastable P63mc hexagonal K2(Ge1-xSix)F6:Mn4+ (KGSFM) with an obvious zero-phonon line peaking at 623.8 nm is stabilized in HF solution. When x = 0.3, the photoluminescence intensity of KGSFM keeps 78% after 168 h in water as well as it increases by 14% at 150 °C (423 K) more than that of KGFM. By using KGSFM the fabricated WLEDs exhibit the high color-rendering index (Ra = 92) and low correlated color temperature (CCT = 3810 K). These results demonstrate that KGSFM solid solution with efficient red emission, meritorious water-proof and high thermal stability is a promising phosphor for the commercial application in the WLEDs and wide-gamut displays.
AB - K2GeF6:Mn4+ (KGFM) phosphors with very poor water-proof property in HF solution transform automatically from P63mc hexagonal phase to P3¯m1 trigonal phase. By substituting Ge4+ ion with Si4+ ion, the metastable P63mc hexagonal K2(Ge1-xSix)F6:Mn4+ (KGSFM) with an obvious zero-phonon line peaking at 623.8 nm is stabilized in HF solution. When x = 0.3, the photoluminescence intensity of KGSFM keeps 78% after 168 h in water as well as it increases by 14% at 150 °C (423 K) more than that of KGFM. By using KGSFM the fabricated WLEDs exhibit the high color-rendering index (Ra = 92) and low correlated color temperature (CCT = 3810 K). These results demonstrate that KGSFM solid solution with efficient red emission, meritorious water-proof and high thermal stability is a promising phosphor for the commercial application in the WLEDs and wide-gamut displays.
KW - High thermal stability
KW - KGeF:Mn
KW - Metastable phase
KW - Red phosphor
KW - Water-proof
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U2 - 10.1016/j.cej.2019.122429
DO - 10.1016/j.cej.2019.122429
M3 - Article
AN - SCOPUS:85070370736
VL - 380
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
M1 - 122429
ER -