Reduced Working Temperature of Quantum Dots-Light-Emitting Diodes Optimized by QDs@Silica-on-Chip Structure

2018 ◽  
Author(s):  
Bin Xie ◽  
Haochen Liu ◽  
Xiao Wei Sun ◽  
Xingjian Yu ◽  
Kai Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diodes ◽  
Temperature Stability ◽  
Phosphor Layer ◽  
Light Emitting ◽  
Yellow Phosphor ◽  
Working Temperature ◽  
On Chip ◽  
White Light Emitting Diodes ◽  
Color Rendering

White light-emitting diodes (WLEDs) composed of blue LED chip, yellow phosphor, and red quantum dots (QDs) are considered as a potential alternative for next-generation artificial light source with their high luminous efficiency (LE) and color-rendering index (CRI). While, QDs’ poor temperature stability and the incompatibility of QDs/silicone severely hinder the wide utilization of QDs-WLEDs. To relieve this, here we proposed a separated QSNs/phosphor structure, which composed of a QSNs-on-chip layer with a yellow phosphor layer above. A silica shell was coated onto the QDs surface to solve the compatibility problem between QDs and silicone. With CRI > 92 and R9 > 90, the newly proposed QDs@silica nanoparticles (QSNs) based WLEDs present 16.7 % higher LE and lower QDs working temperature over conventional mixed type WLEDs. The reduction of QDs’ temperature can reach 11.5 °C, 21.3 °C and 30.3 °C at driving current of 80 mA, 200 mA and 300 mA, respectively.

Reduced Working Temperature of Quantum Dots-Light-Emitting Diodes Optimized by Quantum Dots at Silica-on-Chip Structure

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Bin Xie ◽  
Haochen Liu ◽  
Xiao Wei Sun ◽  
Xingjian Yu ◽  
Ruikang Wu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diodes ◽  
Temperature Stability ◽  
Phosphor Layer ◽  
Light Emitting ◽  
Yellow Phosphor ◽  
Working Temperature ◽  
On Chip ◽  
White Light Emitting Diodes ◽  
Color Rendering

White light-emitting diodes (WLEDs) composed of blue LED chip, yellow phosphor, and red quantum dots (QDs) are considered as a potential alternative for next-generation artificial light source with their high luminous efficiency (LE) and color-rendering index (CRI) while QDs' poor temperature stability and the incompatibility of QDs/silicone severely hinder the wide utilization of QDs-WLEDs. To relieve this, here we proposed a separated QDs@silica nanoparticles (QSNs)/phosphor structure, which composed of a QSNs-on-chip layer with a yellow phosphor layer above. A silica shell was coated onto the QDs surface to solve the compatibility problem between QDs and silicone. With CRI > 92 and R9 > 90, the newly proposed QSNs-based WLEDs present 16.7% higher LE and lower QDs working temperature over conventional mixed type WLEDs. The reduction of QDs' temperature can reach 11.5 °C, 21.3 °C, and 30.3 °C at driving current of 80 mA, 200 mA, and 300 mA, respectively.

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

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.

White Light-Emitting Diodes with Excellent Color Rendering Based on Organically Capped CdSe Quantum Dots and Sr3SiO5:Ce3+,Li+Phosphors

2008 ◽  
Vol 20 (14) ◽  
pp. 2696-2702 ◽  
Author(s):  
Ho Seong Jang ◽  
Heesun Yang ◽  
Sung Wook Kim ◽  
Ji Yeon Han ◽  
Sang-Geun Lee ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emitting Diodes ◽  
Cdse Quantum Dots ◽  
Light Emitting ◽  
White Light Emitting Diodes ◽  
Color Rendering ◽  
Excellent Color
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