Effect of phosphor geometry on the luminous efficiency of high-power white light-emitting diodes with excellent color rendering property

Won, Yong Hyub; Jang, Ho Seong; Cho, Kyoung Woo; Song, Yong Seon; Jeon, Duk Young; Kwon, Ho Ki

doi:10.1364/ol.34.000001

Cited by 127 publications

(37 citation statements)

References 14 publications

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“…Compared to incandescent and fluorescent lamps, white LEDs have many advantages, such as a long lifetime, high efficiency, and lower energy consumption [1]. Most white LEDs use phosphors excited by diode chips with short wavelengths (blue or violet) to reemit a broad spectrum light with a good color-rendering index [2][3][4]. Since the optical performance of LED lighting, including the correlated color temperature (CCT) values, is strongly dependent on the thickness, combination concentration, and geometrical distribution of the phosphors, the commercially available recipes for white LEDs usually require careful manipulation if they are to meet the CCT requirements.…”

Section: Introductionmentioning

confidence: 99%

Optical Modeling Analysis of Red, Green, and Yellow Phosphors with a Blue LED

Sun

Tien

2018

Advances in Condensed Matter Physics

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The luminous properties of red, green, and yellow phosphors with a blue LED are evaluated and a corresponding optical model is constructed using the optical simulation software LightTools5. According to the phosphor particle model, the desired chromaticity coordinate of the multicomponent light which is excited by a blue LED can be achieved by modifying the weight concentration of the phosphors. A comparison of the four types of LED package modules tested shows that the yellow phosphor encapsulated with a semispherical module takes up a lesser percentage of the total weight percentage of a constructed white light with a correlated color temperature of around 4000 K. The simulation and experimental results provide a cross-reference for better packaging and encapsulating designs for lumen improvement.

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Section: Introductionmentioning

confidence: 99%

Optical Modeling Analysis of Red, Green, and Yellow Phosphors with a Blue LED

Sun

Tien

2018

Advances in Condensed Matter Physics

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“…Won et al have demonstrated the strong influence of phosphor geometry on the lumen output of LED lamps with higher color rendering index (CRI) by adding green (Ba,Sr) 2 SiO 4 :Eu 2+ and red CaAlSiN 3 :Eu 2+ phosphors with various phosphor structures to the blue LEDs [4]. Oh et al have proposed G-A-R multi-package LED, which provides higher lumen output and good CRI [5]. Zheng et al have enhanced the CRI of the LED lamp by using multi-chromatic phosphor [6].…”

Section: Introductionmentioning

confidence: 99%

Using Green Emitting Phosphor for Improving Lighting Performance of In-cup Package White LED Lamps

Nhân¹,

Minh²,

Anh³

2017

IJPEDS

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LED technology had a huge development in recent years with major benefits: long-life, high-efficiency, excellent performance, compactness. In this work, an innovative method for improving the performance of multi-chip white LED lamps (MCW-LEDs) by adding the green Ce 0.67 Tb 0.33 MgAl 11 O 19 :Ce,Tb (CeTb) phosphor to their in-cup phosphor compounding is proposed, investigated and demonstrated. Firstly, CeTb was mixed to the incup phosphor package of MCW-LEDs. Then by varying CeTb concentration, lumen output and angular color uniformity (ACU) of MCW-LEDs was calculated and analyzed. The results showed that the lumen output and the ACU of 7000 K and 8500 K MCW-LEDs increased significantly in comparison with others related works. This method is a prospective ideal for future improving LED manufacture.

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“…For the cool WLED at approximately 5000~5500 K, the YAG:Ce phosphor is used to generate the yellow light when pumped by blue source [14]. To achieve the warm WLED at approximately 2700~3000 K, the red phosphor such as nitride-based phosphor is adopted in package and past results have delivered high color-rendering index (CRI) devices [15,16]. However, the red phosphor suffered from the larger stoke shift and causes the cascade excitation process in warm WLEDs, resulting in lower lumen efficiency [17].…”

Section: Introductionmentioning

confidence: 99%

Enhancement of luminous efficiency by hybrid structure for warm white light-emitting diodes

et al. 2014

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This study demonstrates the hybrid structure with high lumen efficiency and uniform angular-dependent correlated color temperature (CCT) for warm white LED. Compared to the conventional structures, the hybrid structure combines the advantage of the two different fabrication methods including dispense and pulse spray method together, which can produce the high quality lighting source. The experimental results indicate that the hybrid structure yielded higher lumen efficiency than conventional phosphor structure because of the gradual refractive index difference from the coating layer to the dispense layer. Moreover, the CCT deviations of the hybrid phosphor structure could be reduced to 65 K in range of −70 to 70 degrees. This is attributed to the uniform color mixing of the blue, yellow and red band in the hybrid phosphor structure. In addition, the chromaticity coordinate shift compared to the hybrid structure with the dispense structure are almost the same at a current regulation from 20 mA to 500 mA. We believe that the technology of the hybrid structure with high lumen efficiency and uniform angular-dependent CCT is suitable for in the general lighting application.

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Effect of phosphor geometry on the luminous efficiency of high-power white light-emitting diodes with excellent color rendering property

Cited by 127 publications

References 14 publications

Optical Modeling Analysis of Red, Green, and Yellow Phosphors with a Blue LED

Optical Modeling Analysis of Red, Green, and Yellow Phosphors with a Blue LED

Using Green Emitting Phosphor for Improving Lighting Performance of In-cup Package White LED Lamps

Enhancement of luminous efficiency by hybrid structure for warm white light-emitting diodes

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