Optical and Color Properties of Green and Red Phosphor Mixtures Doped into Hybrid Sol-Gel Matrix to Generate White Light

2016 ◽  
Vol 1133 ◽  
pp. 419-423 ◽  
Author(s):  
Nurul Huda Yusoff ◽  
Wedianti Shualdi ◽  
Nik Mohd Azmi Nik Abdul Aziz ◽  
Wan Mohammed Nazrul Wan Jaafar
Keyword(s):  
White Light ◽  
Sol Gel ◽  
Color Temperature ◽  
Integrating Sphere ◽  
Green Phosphor ◽  
Red Phosphor ◽  
Color Properties ◽  
Uv Led ◽  
Heat Treated ◽  
Color Rendering

Eu (tta)3phen and Tb (4DBBA)3TPPO were synthesized as red and green phosphor for generating white light under the excitation of UV LED. The phosphor materials were doped into hybrid sol-gel (VTES:TEOS) matrix with different ratio of 1:8, 1:16, 1:25, 1:30, 1:40 and 1:50. The samples were fabricated as thick films by drop-casting and heat treated at 60°C overnight. Photoluminescence spectra were measured using spectrafluorometer system. Measurement of color properties such as color rendering index (CRI), color temperature and Commission Internationale de L’Eclairge coordinates were recorded by exciting the samples using a 380nm UV LED and focused the generated light into an integrating sphere. Based on the results, the mix ratio of 1:40 produce the nearest coordinate within the white color region with color temperature around 4100K to 4200K.

Thermally Stable Encapsulation Material Based on Green and Red Lanthanide Phosphor for White Light Emitting Diodes

2015 ◽  
Vol 815 ◽  
pp. 182-187
Author(s):  
Wedianti Shualdi ◽  
Nik Mohd Azmi ◽  
Nurul Huda Yusoff ◽  
Nor Adhila Muhammad ◽  
Khairuldin Mohd Isha
Keyword(s):  
White Light ◽  
Sol Gel ◽  
Junction Temperature ◽  
Integrating Sphere ◽  
Light Emitting ◽  
Colour Temperature ◽  
Uv Led ◽  
Lanthanides Complexes ◽  
The Stability ◽  
White Light Emitting Diodes

This study reported thermal stability of hybrid sol-gel encapsulation materials doped with lanthanides complexes for generating white light. Red and green lanthanide phosphor, Eu (tta)3phen and Tb (4DBBA)3TPPO were incorporated into VTES:TEOS hybrid sol-gel and dispensed into 360 nm to 390 nm UV LED packages. Thermal properties of developed encapsulation material were analysed by TGA. A thermal aging test up to 96 hours was done to check the stability of developed encapsulation material towards UV LED junction temperature of 120°C and the luminescence properties changes was observed using photoluminescence measurement. To check the encapsulation material stability on forward voltage, the operation voltage has been increased from 3.0V to 4.0V. The photometric measurement were recorded using integrating sphere for the properties of Colour Rendering Index (CRI), colour temperature and Commission Internationale de L’Eclairge (CIE) colour coordinates. Based on the results, developed encapsulation material produced white colour with CIE colour coordinate of (0.32, 0.35), CRI up to 75 and colour temperature around 6000K.

scholarly journals Green fabrication of lanthanide-doped hydroxide-based phosphors: Y(OH)3:Eu3+ nanoparticles for white light generation

2019 ◽  
Vol 10 ◽  
pp. 1200-1210 ◽  
Author(s):  
Tugrul Guner ◽  
Anilcan Kus ◽  
Mehmet Ozcan ◽  
Aziz Genc ◽  
Hasan Sahin ◽  
...  
Keyword(s):  
White Light ◽  
Color Temperature ◽  
Slight Reduction ◽  
Ambient Conditions ◽  
Red Phosphor ◽  
Synthesis Conditions ◽  
Red Phosphors ◽  
White Light Generation ◽  
Color Rendering ◽  
Color Conversion

Phosphors can serve as color conversion layers to generate white light with varying optical features, including color rendering index (CRI), high correlated color temperature (CCT), and luminous efficacy. However, they are typically produced under harsh synthesis conditions such as high temperature, high pressure, and/or by employing a large amount of solvent. In this work, a facile, water-based, rapid method has been proposed to fabricate lanthanide-doped hydroxide-based phosphors. In this sense, sub-micrometer-sized Y(OH)3:Eu3+ particles (as red phosphor) were synthesized in water at ambient conditions in ≤60 min reaction time. The doping ratio was controlled from 2.5–20 mol %. Additionally, first principle calculations were performed on Y(OH)3:Eu3+ to understand the preferable doping scenario and its optoelectronic properties. As an application, these fabricated red phosphors were integrated into a PDMS/YAG:Ce3+ composite and used to generate white light. The resulting white light showed a remarkable improvement (≈24%) in terms of luminous efficiency, a slight reduction of CCT (from 3900 to 3600 K), and an unchanged CRI (≈60) as the amount of Y(OH)3:Eu3+ was increased.

scholarly journals Chromaticity Study of Curcumin Dye Extracted from Curcuma longa L. Using for UV Light down Conversion for White Light Emitting Diode

2019 ◽  
Vol 290 ◽  
pp. 183-189
Author(s):  
Mahmood Al Shafouri ◽  
Naser Mahmoud Ahmed ◽  
Zainuriah Hassan ◽  
Munirah Abdullah Almessiere
Keyword(s):  
White Light ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Curcuma Longa ◽  
Color Temperature ◽  
Light Emitting ◽  
Chromaticity Coordinates ◽  
Major Factors ◽  
Color Rendering ◽  
Down Conversion

In thus study, Turmeric phosphor dye was extracted from Curcuma Longa L. via a simple technique using silica gel. The phosphor was used for light down-conversion of UV light for the manufacture white light emitting diode (WLED). The UV-LED was analyzed over 395nm wavelengths. The characteristics of the white light chromaticity were controlled by tuning the current and phosphor concentration. An optimum color rendering index (CRI) value of 63.4 was obtained. The chromaticity coordinates (CIE) and correlated color temperature (CCT) were measured for various currents and phosphor concentrations. The white phosphor exhibited CIE value of 0.355,0.338 and CCT of 4567 K. The concentration of phosphor and amount of applied current were confirmed to be major factors that control the intensity of white light emitted from the sample, where CIE and CRI of the emitted light steadily increased with the concentration of phosphor and current. Thus, phosphor concentration has a critical effect on conversion efficiency. Key words: Turmeric, phosphor, WLED, curcumin

A red phosphor BaTiF6:Mn4+: reaction mechanism, microstructures, optical properties, and applications for white LEDs

2014 ◽  
Vol 43 (25) ◽  
pp. 9414-9418 ◽  
Author(s):  
Xianyu Jiang ◽  
Zhen Chen ◽  
Shaoming Huang ◽  
Jiaguo Wang ◽  
Yuexiao Pan
Keyword(s):  
Optical Properties ◽  
Reaction Mechanism ◽  
White Light ◽  
Red Phosphor ◽  
White Leds ◽  
Red Phosphors ◽  
Warm White Light ◽  
Color Rendering Index ◽  
Color Rendering

Red phosphors BaTiF6:Mn4+ were obtained by etching Ti(OC4H9)4 and TiO2 with BaF2 in HF and a KMnO4 solution. The WLED fabricated with BaTiF6:Mn4+ exhibits a “warm” white light with a color rendering index of 93.13.

Visible-emitting hybrid sol–gel materials comprising lanthanide ions: thin film behaviour and potential use as phosphors for solid-state lighting

2014 ◽  
Vol 38 (12) ◽  
pp. 5793-5800 ◽  
Author(s):  
Xiaoguang Huang ◽  
Gaël Zucchi ◽  
Jacqueline Tran ◽  
Robert B. Pansu ◽  
Arnaud Brosseau ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solid State ◽  
Sol Gel ◽  
Lanthanide Ions ◽  
Solid State Lighting ◽  
Red Phosphor ◽  
Hybrid Silica ◽  
Uv Led ◽  
Potential Use

Luminescent thin films of hybrid silica-based materials were studied and an Eu-containing one was coated on a near-UV LED chip to be investigated as a red phosphor.

scholarly journals Color Temperature Tunable White-Light LED Cluster with Extrahigh Color Rendering Index

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Minhao Zhang ◽  
Yu Chen ◽  
Guoxing He
Keyword(s):  
White Light ◽  
Experimental Results ◽  
Color Temperature ◽  
Blue Led ◽  
Average Value ◽  
Red Led ◽  
Green Led ◽  
Color Rendering Index ◽  
Color Rendering

The correlated color temperature (CCT) tunable white-light LED cluster with extrahigh color rendering property has been found by simulation and fabricated, which consists of three WW LEDs (CCT = 3183 K), one red LED (634.1 nm), one green LED (513.9 nm), and one blue LED (456.2 nm). The experimental results show that this cluster can realize the CCT tunable white-lights with a color rendering index (CRI) above 93, special CRI R9 for strong red above 90, average value of the special CRIs of R9 to R12 for the four saturated colors (red, yellow, green, and blue) above 83, and luminous efficacies above 70 lm/W at CCTs of 2719 K to 6497 K.

Application of Nitride and Oxynitride Compounds to Various Phosphors for White LED

2008 ◽  
Vol 403 ◽  
pp. 15-18 ◽  
Author(s):  
Kyota Uheda
Keyword(s):  
Rare Earth ◽  
Thermal Quenching ◽  
Rare Earth Ions ◽  
White Led ◽  
Green Phosphor ◽  
Strong Emission ◽  
Red Phosphor ◽  
Blue Phosphor ◽  
Uv Led ◽  
Intense Emission

Multiternary nitride and oxynitride compounds doped with rare earth ions, such as Eu2+ and Ce3+ have been enthusiastically applied as various phosphors to white LED. New red and green phosphors, CaAlSiN3:Eu and Ba3Si6O12N2:Eu, have been successfully synthesized, recently. The red phosphor has intense emission around 650 nm under two different irradiations at 405 and 455 nm from blue- and near UV-LED chips, respectively; while strong emission is observed around 520 nm from the green phosphor. Both phosphors also show small thermal quenching over the temperatures up to 150 °C. In addition, both LaSi3N5:Ce and La3Si8O4N11:Ce in lanthanum silicon nitride and oxynitride were examined as candidates for a blue phosphor in white LED with near UV-LED chip.

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.

The Color Mixing White-Light LEDs

2013 ◽  
Vol 378 ◽  
pp. 440-443
Author(s):  
Chiu Jung Yang ◽  
Chien Sheng Huang ◽  
Chih Wei Chen ◽  
Po Wen Chen
Keyword(s):  
White Light ◽  
Light Emitting Diode ◽  
Optical Power ◽  
Integrating Sphere ◽  
Light Spectrum ◽  
Light Emitting ◽  
Driver Circuit ◽  
Color Mixing ◽  
Color Rendering

Thepaperis discussedin coloruniformity study.The experiment divided into two steps in this study,first is modules design and simulation. Second is fabrication and measurement.After measure the LEDs property, calculating the ratio of each colored LEDs by using Grassmanns Law,modeling by Solidworks, and simulating the front study by optical software TracePro.Using four-color mixing with self-developed formula to avoid the present white light emitting diode patent, and the four-color grains are Red, Green, Blue and adding Y to modify the overall quality of the mixed light.The phosphorproduceSteabler-Wronsk hardly in the high temperatureas compared tofour-color mixing.Using four-color mixing to producehigher color rendering index than yellow phosphor.Series-parallel array of grain arrangement adopted to achieve the high demand for uniformity, while simplifying the design conditions by a certain current instead of the general mixed light-driven complex driver circuit,the completion of the mixing module using integrating sphere, light spectrum on the spectrophotometer, optical power, color coordinates values, such as mixing uniformity measurements.The chromaticity coordinates errors after complete results of the mixing module measurement and simulation can be controlled under (0.01x, 0.01y).

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