White-electroluminescent device with horizontally patterned blue/yellow phosphor-layer structure

2007 ◽  
Vol 127 (2) ◽  
pp. 531-533 ◽  
Author(s):  
Boo Won Park ◽  
Nam Sik Choi ◽  
Kwang Won Park ◽  
So Mo Son ◽  
Jong Su Kim ◽  
...  
Keyword(s):  
Layer Structure ◽  
Phosphor Layer ◽  
Yellow Phosphor ◽  
Electroluminescent Device

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.

Characterization of Brightness of ZnS Electroluminescent Device with Dielectric Materials of SOG or TEOS

2008 ◽  
Vol 55 ◽  
pp. 160-163
Author(s):  
Sung Min Park ◽  
Mun Ja Kim ◽  
Sang Hyun Park ◽  
Jin Young Kim ◽  
Ji Beom Yoo
Keyword(s):  
Spin Coating ◽  
Dielectric Material ◽  
Dielectric Materials ◽  
Organic Binder ◽  
Layer Formation ◽  
Phosphor Layer ◽  
Electroluminescent Device ◽  
Coating Method ◽  
Powder Type

Spin on glass (SOG) and Tetraethylorthosilicate (TEOS) as a dielectric material were applied for inorganic powder type electroluminescent (EL) device. The spin coating method was used for the SOG layer or TEOS layer formation and phosphor layer formation. The phosphor layer was composed of ZnS:Cu,Cl powders and organic binder. The brightness of powder EL has been measured.

Organic Electroluminescent Device with a Three-Layer Structure

1988 ◽  
Vol 27 (Part 2, No. 4) ◽  
pp. L713-L715 ◽  
Author(s):  
Chihaya Adachi ◽  
Shizuo Tokito ◽  
Tetsuo Tsutsui ◽  
Shogo Saito
Keyword(s):  
Layer Structure ◽  
Electroluminescent Device ◽  
Organic Electroluminescent

AC-Electroluminescent Device Having a ZnS:Mn Single Crystal Phosphor Layer

1985 ◽  
Vol 24 (Part 2, No. 8) ◽  
pp. L629-L631 ◽  
Author(s):  
Katsuhiko Hirabayashi ◽  
Katsumi Katoh
Keyword(s):  
Single Crystal ◽  
Crystal Phosphor ◽  
Phosphor Layer ◽  
Electroluminescent Device

scholarly journals Improvement of double-layer phosphor structure WLEDS in color homogeneity and luminous flux

2021 ◽  
Vol 10 (5) ◽  
pp. 2513-2519
Author(s):  
Dieu An Nguyen Thi ◽  
Phung Ton That ◽  
Hoang Nam Nguyen
Keyword(s):  
Luminous Flux ◽  
Small Reduction ◽  
Phosphor Layer ◽  
Green Phosphor ◽  
Yellow Phosphor ◽  
Color Quality ◽  
Quality Scale ◽  
Remote Phosphor ◽  
Distinct Color ◽  
Color Rendering

The concept of the analysis is to put a CaAl2O4:Mn2+ green phosphor layer on top of the YAG:Ce3+ yellow phosphor layer. After that, find the added CaAl2O4:Mn2+ concentration appropriate for the highest luminous flux (LF) and color homogeneity (CH). In this analysis, five equivalent WLEDs were applied but with distinct color temperatures, including 5600 K - 8500 K. The findings showed that CaAl2O4:Mn2+ brings great benefits to increase not only the luminous flux but also the color homogeneity. Especially, the higher the CaAl2O4:Mn2+ concentration, the more the luminous flux released by WLEDs, owing to the risen content of the light of green in WLEDs. Nevertheless, as the CaAl2O4:Mn2+ concentration raised significantly, a small reduction in the color rendering metric (CRI) and color quality scale (CQS) occurred. This is supported by simulation and calculation according to the theory of Monte Carlo. The paper results are the crucial contribution to the manufacture of WLEDs with better optical performance and color homogeneity of remote phosphor configurations.

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.

scholarly journals The study of convex-dual-layer remote phosphor geometry in upgrading WLEDs color rendering index

2021 ◽  
Vol 11 (5) ◽  
pp. 3890
Author(s):  
Huu Phuc Dang ◽  
Nguyen Thi Phuong Loan ◽  
Nguyen Thi Kim Chung ◽  
Nguyen Doan Quoc Anh
Keyword(s):  
Double Layer ◽  
Layer Structure ◽  
Light Emitting Diode ◽  
Light Output ◽  
Color Temperature ◽  
Phosphor Layer ◽  
Red Phosphor ◽  
Remote Phosphor ◽  
Color Rendering Index ◽  
Color Rendering

<span>The white-light light-emitting diode (LED) is a semiconductor light source that usually has one chip and one phosphor layer. Because of that simple structure, the color rendering index (CRI) is really poor. Therefore, structure with double layer of phosphor and multiple chips has been studied with the phosphorus proportions and densities in the silicone are constantly changed to find the best option to improve optical properties. In research, we use red phosphor Ca5B2SiO10:Eu3+ layer to place above the yellow phosphor one, and both of them have a convex design. Then, the experiments and measurements are carried out to figure out the effects of this red phosphor as well as the convex-double-layer remote phosphor design on the LED’s performances. The measured results reveal that the light output is enhanced significantly when using convex-dual-layer structure instead of the single-layer design. Additionally, the Ca5B2SiO10:Eu3+ concentration benefits CRI and CQS at around 6600 K and 7700 K correlated color temperature (CCT). Yet, the lumen output shows a slight decline as this red phosphor concentration surpass 26% wt. Through the experiments, it is found that a double layer of chip and double phosphorus is the best structure which could support the quality of CRI and luminous flux.</span>

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