Synthesis and luminescence properties of (Lu0.95−xCe0.05)2Ca1+2xMg2Si3O12 silicate garnet phosphors and its applications

2016 ◽  
Vol 09 (03) ◽  
pp. 1650049
Author(s):  
Wei Xia ◽  
Xiyan Zhang ◽  
Liping Lu
Keyword(s):  
Light Emitting Diode ◽  
Red Light ◽  
Emission Spectra ◽  
Peak Wavelength ◽  
Excitation Peak ◽  
Light Emitting ◽  
White Leds ◽  
Reducing Atmosphere ◽  
Color Rendering ◽  
Silicate Garnet

Silicate garnet phosphors (Lu[Formula: see text]Ce[Formula: see text]Ca[Formula: see text]Mg2Si3O[Formula: see text] with [Formula: see text], 0.05, 0.1, and 0.15 were prepared by high-temperature solid-state reaction in a reducing atmosphere. The crystal structure, photoluminescence and luminescence of the phosphors were investigated. The optimum excitation peak wavelength of the phosphors ranged from 450[Formula: see text]nm to 490[Formula: see text]nm, matching the emission spectra of a blue light-emitting diode chip. The phosphors emit orange-red light after excitation that can be tuned from 589[Formula: see text]nm to 597[Formula: see text]nm by changing the concentration of calcium ions. In addition, their emission made them suitable for use in warm-white LEDs with a high-color rendering index.

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.

scholarly journals Preparation and photoluminescence study of Alumin o-boro silicate YAG fluorescent glass for White LED

2021 ◽  
Author(s):  
Chao Yang ◽  
Guohua Song ◽  
Jianwen Miao ◽  
Tingting Fan
Keyword(s):  
Light Emitting Diode ◽  
Emission Spectra ◽  
Precipitation Method ◽  
Excitation Spectra ◽  
Fluorescence Excitation ◽  
Light Emitting ◽  
White Leds ◽  
Near Ultraviolet ◽  
Fluorescence Excitation Spectra ◽  
Co Precipitation

Abstract The YAG: Eu 3+ fluorescent glass for NUV(near ultraviolet) white LEDs was obtained firstly by synthesizing Y 3 Al 5 O 12 (YAG): Eu 3+ precursors through a simple co-precipitation method, and then mixing precursor with B 2 O 3 -Al 2 O 3 -SiO 2 -Na 2 O-BaO glass powder calcined at 1400°C for 2.5 hours. The as-prepared YAG glass-ceramic phosphor was investigated by DTA, XRD, SEM, and photoluminescence (PL). Influence of YAG: Eu 3+ precursor and Eu 3+ doping on excitation and emission spectra also have been studied. The results show that: the phosphor's emission peak located at 393nm is correspond to the 7 F 0 - 5 L 6 transition of Eu 3+ ions, which matches good with UV LED chips; the phosphor gives intense emission at 593nm originating from the 5 D 0 - 7 F 1 transition of Eu 3+ ions. When the YAG precursor is 0.9g and amount of Eu 3+ doped is 0.08, the fluorescence excitation spectra of glass and emission spectra of the peak intensity reach its maximum value. The YAG: Eu 3+ fluorescence glass could be a promising material for the production of near ultraviolet chip white light-emitting diode.

Luminescence Properties of Magnesium Sodium Borate Glasses Doped Sm3+, Dy3+ and Eu3+

2020 ◽  
Vol 307 ◽  
pp. 314-320
Author(s):  
Abd Rahman Tamuri ◽  
Aryna Abdul Majid ◽  
Rosli Husin
Keyword(s):  
Light Emitting Diode ◽  
Energy Levels ◽  
Red Light ◽  
Emission Spectra ◽  
Luminescence Properties ◽  
Sodium Borate ◽  
Borate Glasses ◽  
Absorption Bands ◽  
Light Emitting ◽  
Color Displays

The luminescence properties Dy3+, Eu3+ and Sm3+ doped magnesium sodium borate glasses were investigated. The glasses samples containing the composition 30MgO-70Na2B4O7.10H2O-xRE2O3 (where RE = Dy3+, Eu3+, and Sm3+, x = 0.1, 0.5, and 1.0 mol %) are prepared by the conventional melt quenching technique. The optical properties have been evaluated using Ultraviolet-Visible Spectroscopy and Photoluminescence Spectroscopy. The X-ray Diffraction pattern was studied to confirm the amorphous nature of the prepared glass. The absorption spectra yield the most intense absorption bands and transition energy levels for Dy3+, Eu3+, and Sm3+ located at 347 nm (6H15/2 → 6P7/2), 393 nm (7F0 → 5L6), and 403 nm (6H5/2 →6P5/2) respectively. The emission spectra demonstrate the highest emission intensity centered at 463 nm (4F9/2 → 6F11/2 + 6H9/2), 612 nm (5D0 → 7FJ), and 599 nm (4G5/2 → 6H7/2) for Dy3+, Eu3+, and Sm3+ respectively. Dy3+ emits combination of blue, yellow, and red light, Eu3+ emits red light and Sm3+ emits orange to red light. The higher the content of Dy3+, Eu3+, and Sm3+, the higher the spectral or peak intensity for both absorption and emission. The findings could be useful for development of laser, light emitting diode (LED), and color displays applications. KEY WORDS: Luminescence, Borax glass, Magnesium, Dysprosium, Europium, Samarium.

scholarly journals Study on the Color-Compensation Effect of Composite Orange-Red Quantum Dots in WLED Application

2020 ◽  
Author(s):  
Xiaoyue Hu ◽  
Yangyang Xie ◽  
Chong Geng ◽  
Shu Xu ◽  
Wengang Bi
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diode ◽  
Red Light ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Light Emitting ◽  
Light Region ◽  
Color Compensation ◽  
Donor Acceptor ◽  
Color Rendering

Abstract Quantum dots (QDs) as emerging light-converting materials show the advantage of enhancing color quality of white light-emitting diode (WLED). However, WLEDs employing narrow-emitting monochromic QDs usually present unsatisfactory color rendering in the orange region. Herein, composite orange-red QDs (composite-QDs) are developed through mixing CdSe/ZnS based orange QDs (O-QDs) and red QDs (R-QDs) to compensate the orange-red light for WLEDs. We investigated the effect of self-absorption and fluorescence resonance energy transfer (FRET) process in composite-QDs on the spectral controllability and fluorescent quenching in WLEDs. The concentration and donor/acceptor ratios were also taken into account to analyze the FRET efficiency and help identify suitable composite-QDs for color compensation in the orange-red light region. As the result, the optimized composite-QDs effectively improve the color rendering index of the WLED compared with monochromatic QDs.

Synthesis and Luminescent Properties of Red Phosphor BaY2O4: Eu3+ for White Light-Emitting Diodes

2013 ◽  
Vol 811 ◽  
pp. 181-185 ◽  
Author(s):  
Lan Tu Ya Wu
Keyword(s):  
Sol Gel ◽  
Red Light ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Electric Dipole Transition ◽  
Excitation Spectra ◽  
Excitation Peak ◽  
Red Phosphor ◽  
Light Emitting ◽  
White Light Emitting Diodes

The rare-earth Eu3+doped BaY2O4red phosphor synthesized by citric acid sol-gel method. The structure, morphology and composition of the red phosphor were characterized by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. The results show that the distribution of the pure phase BaY2O4: Eu3+particles after annealing at 800 °C was irregular, small size of particle is 0.2 μm to 0.4 μm. The excitation spectra of synthesized phosphor at 610 nm monitoring were composed of a broadband and a series of sharp peaks, the strongest excitation peak at 466 nm, the secondly at 395nm. It was indicated that BaY2O4: Eu3+phosphor matching with the widespread applied the output wavelengths of UV LED and blue LED chips. The main emission spectra of samples under blue light excitation is Eu3+ions5D07F2electric dipole transition with a strong red light, so that the BaY2O: Eu3+phosphor may be a better candidate for red component for white LED.

scholarly journals Multicolor and Warm White Emissions with a High Color Rendering Index in a Tb3+/Eu3+-Codoped Phosphor Ceramic Plate

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2240
Author(s):  
Haggeo Desirena ◽  
Jorge Molina-González ◽  
Octavio Meza ◽  
Priscilla Castillo ◽  
Juan Bujdud-Pérez
Keyword(s):  
Energy Transfer ◽  
Light Emitting Diode ◽  
Maximum Energy ◽  
Luminescence Spectra ◽  
Ceramic Plate ◽  
Light Emitting ◽  
White Leds ◽  
Near Ultraviolet ◽  
Color Rendering Index ◽  
Color Rendering

A series of Tb3+/Eu3+-codoped phosphor ceramic plates with a high color rendering index (CRI) for a near-ultraviolet light emitting diode (LED) were fabricated. Color emission can be tuned from green to reddish as a function of Eu3+ concentration. By doping only 0.15 mol% of Eu3+ concentration, a comfortable warm white emission is promoted as a result of simultaneous emissions of Tb3+ and Eu3+ ions. A theoretical model is proposed to calculate the contributions of the emitted color of the donor (Tb3+) and acceptor (Eu3+) ions in terms of europium concentration. The energy transfer from Tb3+ to Eu3+ ions is corroborated by the luminescence spectra and decay time of Tb3+, with a maximum energy transfer efficiency of 76% for 28 mol% of Tb3+ and 14 mol% of Eu3+. Warm white LEDs were constructed using a 380 nm UV chip and showed a CRI of 82.5, which was one of highest values reported for Tb3+/Eu3+-codoped samples. Color-correlated temperature (CCT), color coordinate (CC), and luminous efficacy (LE) were utilized to know the potentials as a phosphor converter in solid-state lighting.

Study on the Color-Compensation Effect of Hybrid Orange-Red Quantum Dots in WLED Application

2020 ◽  
Author(s):  
Xiaoyue Hu ◽  
Yangyang Xie ◽  
Chong Geng ◽  
Shu Xu ◽  
Wengang Bi
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diode ◽  
Red Light ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Light Emitting ◽  
Light Region ◽  
Color Compensation ◽  
Donor Acceptor ◽  
Color Rendering

Abstract Quantum dots (QDs) as emerging light-converting materials show the advantage of enhancing color quality of white light-emitting diode (WLED). However, WLEDs employing narrow-emitting monochromic QDs usually present unsatisfactory color rendering in the orange region. Herein, orange-red emitting polychromic hybrid QDs (hybrid-QDs) are developed through mixing CdSe/ZnS based orange QDs (O-QDs) and red QDs (R-QDs) to compensate the orange-red light for WLEDs. We investigated the effect of self-absorption and fluorescence resonance energy transfer (FRET) process in hybrid-QDs on the spectral controllability and fluorescent quenching in WLEDs. The concentration and donor/acceptor ratios were also taken into account to analyze the FRET efficiency and help identify suitable hybrid-QDs for color compensation in the orange-red light region. As the result, the optimized hybrid-QDs effectively improve the color rendering index of the WLED compared with monochromatic QDs at the same color coordinates.

A design methodology for phosphor mixtures for tunable spectrum LEDs

MRS Advances ◽  
2016 ◽  
Vol 1 (50) ◽  
pp. 3435-3440 ◽  
Author(s):  
Partha S. Dutta ◽  
Kathryn M. Liotta
Keyword(s):  
Design Methodology ◽  
Emission Spectra ◽  
Full Spectrum ◽  
Light Emitting ◽  
White Leds ◽  
Fixed Weight ◽  
Wide Range ◽  
Color Rendering Index ◽  
White Light Emitting Diodes ◽  
Color Rendering

ABSTRACT Spectrum tuning in phosphor converted white light emitting diodes (pc-WLED) is done by mixing powders of phosphor compounds (with different emission wavelengths) in different weight ratios. In this paper, a new methodology for designing unique full spectrum phosphor mixtures (with fixed weight ratios of different emission phosphor) has been presented that could provide a wide range of pc-WLED spectrum. This is done by optimizing the excitation and emission spectra of the phosphor compounds used in the mixture. A unique phosphor mixture comprising of Eu2+ and Ce3+-Na1+ activated compounds of SrGa2S4, CaGa2S4, SrS, CaS and CaF2 was used to produce full spectrum warm, neutral and cool white LEDs with color temperatures between 2500 K and 7500 K and with color rendering index exceeding 95.

scholarly journals Red Light-Emitting Diodes with All-Inorganic CsPbI3/TOPO Composite Nanowires Color Conversion Films

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Lung-Chien Chen ◽  
Yi-Tsung Chang ◽  
Ching-Ho Tien ◽  
Yu-Chun Yeh ◽  
Zong-Liang Tseng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diode ◽  
Red Light ◽  
Trioctylphosphine Oxide ◽  
Optical And Electrical Properties ◽  
Colloidal Solutions ◽  
High Quality ◽  
Light Emitting ◽  
Hot Injection ◽  
Color Conversion

AbstractThis work presents a method for obtaining a color-converted red light source through a combination of a blue GaN light-emitting diode and a red fluorescent color conversion film of a perovskite CsPbI3/TOPO composite. High-quality CsPbI3 quantum dots (QDs) were prepared using the hot-injection method. The colloidal QD solutions were mixed with different ratios of trioctylphosphine oxide (TOPO) to form nanowires. The color conversion films prepared by the mixed ultraviolet resin and colloidal solutions were coated on blue LEDs. The optical and electrical properties of the devices were measured and analyzed at an injection current of 50 mA; it was observed that the strongest red light intensity was 93.1 cd/m2 and the external quantum efficiency was 5.7% at a wavelength of approximately 708 nm when CsPbI3/TOPO was 1:0.35.

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