Improvement in optical performance and color uniformity by optimizing the remote phosphor caps geometry for chip-on-board light emitting diodes

2016 ◽  
Vol 126 ◽  
pp. 36-45 ◽  
Author(s):  
Jiasheng Li ◽  
Zongtao Li ◽  
Zhi Li ◽  
Yong Tang ◽  
Xinrui Ding ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Optical Performance ◽  
Light Emitting ◽  
Color Uniformity ◽  
Remote Phosphor

Enhancement of angular color uniformity of remote-phosphor-converted light-emitting diodes by electrospun-nanofiber diffusing films

2018 ◽  
Vol 227 ◽  
pp. 104-107 ◽  
Author(s):  
Yong Tang ◽  
Guanwei Liang ◽  
Cunjiang Song ◽  
Zongtao Li ◽  
Shudong Yu ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Electrospun Nanofiber ◽  
Light Emitting ◽  
Color Uniformity ◽  
Remote Phosphor

scholarly journals Micro-Prism Patterned Remote Phosphor Film for Enhanced Luminous Efficiency and Color Uniformity of Phosphor-Converted Light-Emitting Diodes

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1117
Author(s):  
Jiadong Yu ◽  
Shudong Yu ◽  
Ting Fu ◽  
Yong Tang
Keyword(s):  
Light Emitting Diodes ◽  
Color Stability ◽  
Luminous Flux ◽  
Luminous Efficiency ◽  
Light Emitting ◽  
Exit Surface ◽  
Roll To Roll ◽  
Color Uniformity ◽  
Remote Phosphor ◽  
Phosphor Film

In this work, we propose micro-prism patterned remote phosphor (RP) films to enhance both luminous efficiency and color uniformity (CU) of remote phosphor-converted light-emitting diodes (rpc-LEDs) simultaneously. On the incident surface of the RP film, one micro-prism film is used to extract backward light by double reflection. On the exit surface, the other micro-prism film is adopted to retain blue light inside the RP film, thus enhancing the phosphor excitation. Experimental results show that double prism-patterned RP (DP-RP) film configuration shows a luminous flux of 55.16 lm, which is 45.1% higher than that of RP film configuration at 300 mA. As regards the CU, the DP-RP film configuration reduces the angular CIE-x and CIE-y standard variations by 68% and 69.32%, respectively, compared with the pristine device. Moreover, the DP-RP film configuration shows excellent color stability under varying driving currents. Since micro-prism films can be easily fabricated by a roll-to-roll process, the micro-prism patterned RP film can be an alternative to a conventional RP layer to enable the practical application of rpc-LEDs.

Optical performance enhancement of chip-on-board light-emitting diodes through ionic wind patterning

2017 ◽  
Vol 56 (12) ◽  
pp. 3397 ◽  
Author(s):  
Jiading Wu ◽  
Jingcao Chu ◽  
Zefeng Zhang ◽  
Jiahui Huang ◽  
Huai Zheng ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Performance Enhancement ◽  
Ionic Wind ◽  
Optical Performance ◽  
Light Emitting

scholarly journals (Y,Gd)BO3:Eu red phosphor for dual-layer phosphor structure to enhance the optical performance of white light-emitting diodes

2021 ◽  
Vol 10 (4) ◽  
pp. 1930-1935
Author(s):  
Phan Xuan Le ◽  
Le Hung Tien
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Phosphor Layer ◽  
Light Emitting ◽  
Conformal Coating ◽  
Color Quality ◽  
Remote Phosphor ◽  
White Light Emitting Diodes ◽  
Color Rendering

Among the structures using for fabricating white light-emitting diodes (WLEDs) such as the conformal coating or in-cup geometries, the remote phosphor structure gives the highest luminous efficacy. However, in terms of color quality, its performance is not as good as the others. The red-light compensation has been reported as the effective solution for enhancing the color quality of WLEDs. Hence, this study adopted the idea and applied to the dual-layer phosphor structure. The phosphor used to boost the red color in light formation is (Y,Gd)BO3:Eu particle. The dual-layer remote phosphor structure was simulated with the red (Y,Gd)BO3:Eu phosphor layer above the original yellow phosphor YAG:Ce3+ one. The WLEDs with different correlated color temperatures of 5600 K, 6600 K and 7700K were experimented. Mie-theory and Lambert-Beer law were applied to examine the results. The growth in color rendering index (CRI) and color quality scale (CQS) with the increase of (Y,Gd)BO3:Eu phosphor concentration was observed. Nevertheless, the lumen efficacy would be degraded if the concentration was over a certain number. The information provided in this article is useful for the development of high-power WLED production with greater color quality.

High Color Uniformity of White Light-Emitting Diodes Using Chip-Scaled Package

2018 ◽  
Vol 30 (11) ◽  
pp. 989-992 ◽  
Author(s):  
Zongtao Li ◽  
Yong Tang ◽  
Jiasheng Li ◽  
Canbiao Wu ◽  
Xinrui Ding ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Color Uniformity ◽  
White Light Emitting Diodes

Inserting a AlN Electron Blocking Layer for InGaN/GaN Blue Light-Emitting Diodes

2020 ◽  
Vol 1014 ◽  
pp. 126-130
Author(s):  
Wan Sheng Zuo ◽  
Yin Xi Niu ◽  
Liu Yang ◽  
Xiu Zhen Chi ◽  
Jin Jin Liu ◽  
...  
Keyword(s):  
Blue Light ◽  
Barrier Layer ◽  
Light Emitting Diodes ◽  
Electrostatic Discharge ◽  
Blocking Layer ◽  
Optical Performance ◽  
Spreading Effect ◽  
Electron Blocking Layer ◽  
Light Emitting ◽  
Wide Range

In this study, the advantages of the AlN electron blocking layer (EBL) for InGaN/GaN blue light-emitting diodes (LEDs) were investigated. The LEDs with the AlN EBL exhibited better optical performance over a wide range of carrier concentration due to the suppression of electron overflow. Furthermore, the AlN EBL with a thicker last barrier layer was investigated. The thicker last barrier layer was used to enhance Electrostatic Discharge (ESD) characteristic by the better current spreading effect.

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