Co-Precipitation Synthesis and Photoluminescence Properties of K2SiF6:Mn4+ Red Phosphor for White Light Emitting Diodes

2019 ◽  
Vol 807 ◽  
pp. 101-109
Author(s):  
Di Wu ◽  
Xin Yu Ye ◽  
Lin Sheng Wang ◽  
Qing Hua Zeng
Keyword(s):  
White Light ◽  
Luminescent Properties ◽  
Color Temperature ◽  
Precipitation Method ◽  
Light Emitting ◽  
Warm White Light ◽  
Co Precipitation ◽  
White Light Emitting Diodes ◽  
Color Rendering ◽  
Fluorescence Spectrometer

A novel red-emitting K2SiF6:Mn4+ phosphors with different Mn4+ doping mole fraction were synthesized by co-precipitation method. X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and fluorescence spectrometer were used to characterize the properties of K2SiF6:Mn4+ phosphors. As-prepared K2SiF6:Mn4+ phosphors have cubic crystal structure. Under excitation at 450 nm, an intense red emission peak around 632 nm corresponding to the 2Eg-4A2 transition of Mn4+ was observed for 8.37 mol% K2SiF6:Mn4+ phosphors and was used as the optimum doping concentration. The excellent luminescent properties make the phosphor K2SiF6:Mn4+ a candidate for applications in InGaN-YAG:Ce3+ type LEDs for high color rendering. “A warm” white light LED with an efficiency of 147 lm/w and a color rendering index of 87.4 at a color temperature of 2864K has been obtained by fabricating YAG:Ce3+ with K2SiF6:Mn4+ on an InGaN chip.

Red-emitting phosphors Na2XF6:Mn4+(X = Si, Ge, Ti) with high colour-purity for warm white-light-emitting diodes

RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58136-58140 ◽  
Author(s):  
Zhengliang Wang ◽  
Yong Liu ◽  
Yayun Zhou ◽  
Qiang Zhou ◽  
Huiying Tan ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Precipitation Method ◽  
Light Emitting ◽  
Warm White Light ◽  
Co Precipitation ◽  
White Light Emitting Diodes

Red hexafluoride phosphors were synthesized by a simple co-precipitation method. WLEDs fabricated with as-prepared phosphors emit intense warm white-light under 20 mA current excitation. Therefore, they may find application in warm WLEDs.

53% Efficient Red Emissive Carbon Quantum Dots for High Color Rendering and Stable Warm White‐Light‐Emitting Diodes

2017 ◽  
Vol 29 (37) ◽  
pp. 1702910 ◽  
Author(s):  
Zifei Wang ◽  
Fanglong Yuan ◽  
Xiaohong Li ◽  
Yunchao Li ◽  
Haizheng Zhong ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emitting Diodes ◽  
Carbon Quantum Dots ◽  
Light Emitting ◽  
Warm White Light ◽  
White Light Emitting Diodes ◽  
Color Rendering

Co-precipitation Synthesis and Luminescence Properties of Na2TiF6∶Mn4+Red Phosphors for Warm White Light Emitting Diodes

2015 ◽  
Vol 36 (12) ◽  
pp. 1402-1408 ◽  
Author(s):  
罗 洋 LUO Yang ◽  
江建青 JIANG Jian-qing ◽  
侯得健 HOU De-jian ◽  
游维雄 YOU Wei-xiong ◽  
叶信宇 YE Xin-yu
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Luminescence Properties ◽  
Light Emitting ◽  
Red Phosphors ◽  
Warm White Light ◽  
Precipitation Synthesis ◽  
Co Precipitation ◽  
White Light Emitting Diodes

scholarly journals High Efficiency and Color Rendering Quantum Dots White Light Emitting Diodes Optimized by Luminescent Microspheres Incorporating

Nanophotonics ◽  
2016 ◽  
Vol 5 (4) ◽  
pp. 565-572 ◽  
Author(s):  
Wei Chen ◽  
Kai Wang ◽  
Junjie Hao ◽  
Dan Wu ◽  
Jing Qin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
High Efficiency ◽  
Lattice Structure ◽  
Light Emitting Diode ◽  
Luminescent Properties ◽  
Color Temperature ◽  
High Quantum Efficiency ◽  
Light Emitting ◽  
Color Rendering

AbstractIn this research, we have developed an approach by incorporating quantum dots (QDs) with red emission into mesoporous silica microspheres through a non-chemical process and obtained luminescent microspheres (LMS). Owing to the lattice structure of LMS, QDs were effectively protected from intrinsic aggregation in matrix and surface deterioration by encapsulant, oxygen and moisture. The LMS composite has therefore maintained large extent luminescent properties of QDs, espe-cially for the high quantum efficiency. Moreover, the fabricated white light emitting diode (WLED) utilizing LMS and YAG:Ce yellow phosphor has demonstrated excellent light performance with color coordinates around (x = 0.33, y = 0.33), correlated color temperature between 5100 and 5500 K and color rendering index of Ra = 90, R9 = 95. The luminous efficiency of the WLED has reached up to a new record of 142.5 lm/W at 20 mA. LMS provide a promising way to practically apply QDs in lightings and displays with high efficiency as well as high stability.

Red Phosphor Rb2NbOF5:Mn4+ for Warm White Light-Emitting Diodes with a High Color-Rendering Index

2018 ◽  
Vol 58 (1) ◽  
pp. 456-461 ◽  
Author(s):  
Zhengliang Wang ◽  
Zhiyu Yang ◽  
Zhaofeng Yang ◽  
Qianwen Wei ◽  
Qiang Zhou ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Red Phosphor ◽  
Light Emitting ◽  
Warm White Light ◽  
Color Rendering Index ◽  
White Light Emitting Diodes ◽  
Color Rendering

scholarly journals A broadband cyan-emitting Ca2LuZr2(AlO4)3:Ce3+ garnet phosphor for near-ultraviolet-pumped warm-white light-emitting diodes with an improved color rendering index

2020 ◽  
Vol 8 (3) ◽  
pp. 1095-1103 ◽  
Author(s):  
Liangling Sun ◽  
Balaji Devakumar ◽  
Jia Liang ◽  
Shaoying Wang ◽  
Qi Sun ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Emission Spectra ◽  
Light Emitting ◽  
White Leds ◽  
Near Ultraviolet ◽  
Warm White Light ◽  
Color Rendering Index ◽  
White Light Emitting Diodes ◽  
Color Rendering

Broadband cyan-emitting Ca2LuZr2(AlO4)3:Ce3+ garnet phosphors enabled to fill the cyan gap in the emission spectra of near-ultraviolet-pumped warm-white LEDs, thus resulting in improved color rendering index.

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