scholarly journals Selected Scattering on Quasi-Ordered Hexagonal Close-Packed Al Nanodents for Tunable Output of White LEDs

2019 ◽  
Vol 9 (17) ◽  
pp. 3626
Author(s):  
Junfeng Zhao ◽  
Xinxiang Yu ◽  
Zhiguo Zhao ◽  
Xiaoyan Dong ◽  
Dandan Shi ◽  
...  
Keyword(s):  
Near Field ◽  
Light Emitting ◽  
White Leds ◽  
Long Wavelength ◽  
Hexagonal Close Packed ◽  
Light Coupling ◽  
Short Wavelength Light ◽  
White Light Emitting Diodes ◽  
Wavelength Light ◽  
Effect Of Light

Quasi-ordered hexagonal close-packed Al nanodents, with depths of 30 nm and top-diameters of 300 nm prepared by electrochemical anodizing, are used to manage the output spectrum of white Light Emitting Diodes (LEDs). Significant short wavelength light, with a peak of 450 nm, displays significant scattering enhancements on these Al nanodents with the increment of the angle of the incidence, while long wavelength light, with a peak of 550 nm, shows weaker scattering on Al nanodents with the increment of theincidence angle. Near-field and far-field simulations reveal the effect of light coupling in the holes of Al nanodents on the selected scattering. This work could provide a striking new way to make use of cheap white LEDs.

scholarly journals Demonstration of epitaxial growth of strain-relaxed GaN films on graphene/SiC substrates for long wavelength light-emitting diodes

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ye Yu ◽  
Tao Wang ◽  
Xiufang Chen ◽  
Lidong Zhang ◽  
Yang Wang ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Light Emitting Diodes ◽  
Nitrogen Plasma ◽  
Biaxial Stress ◽  
Organic Chemical ◽  
Graphene Surface ◽  
Light Emitting ◽  
Long Wavelength ◽  
Pre Treatment ◽  
Wavelength Light

AbstractStrain modulation is crucial for heteroepitaxy such as GaN on foreign substrates. Here, the epitaxy of strain-relaxed GaN films on graphene/SiC substrates by metal-organic chemical vapor deposition is demonstrated. Graphene was directly prepared on SiC substrates by thermal decomposition. Its pre-treatment with nitrogen-plasma can introduce C–N dangling bonds, which provides nucleation sites for subsequent epitaxial growth. The scanning transmission electron microscopy measurements confirm that part of graphene surface was etched by nitrogen-plasma. We study the growth behavior on different areas of graphene surface after pre-treatment, and propose a growth model to explain the epitaxial growth mechanism of GaN films on graphene. Significantly, graphene is found to be effective to reduce the biaxial stress in GaN films and the strain relaxation improves indium-atom incorporation in InGaN/GaN multiple quantum wells (MQWs) active region, which results in the obvious red-shift of light-emitting wavelength of InGaN/GaN MQWs. This work opens up a new way for the fabrication of GaN-based long wavelength light-emitting diodes.

Three-dimensional GaN dodecagonal ring structures for highly efficient phosphor-free warm white light-emitting diodes

Nanoscale ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 4686-4695 ◽  
Author(s):  
Young Chul Sim ◽  
Seung-Hyuk Lim ◽  
Yang-Seok Yoo ◽  
Min-Ho Jang ◽  
Sunghan Choi ◽  
...  
Keyword(s):  
White Light ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Three Dimensional ◽  
Light Emitting ◽  
White Leds ◽  
Highly Efficient ◽  
Warm White Light ◽  
Ring Structures ◽  
White Light Emitting Diodes

Multifaceted dodecagonal ring structures emit light of various colours with high efficiency and are demonstrated to be phosphor-free white LEDs.

Novel polygonal structure Mn4+ activated In3+-based Elpasolite-type hexafluorides red phosphor for warm white light-emitting diodes (WLEDs)

2019 ◽  
Vol 48 (4) ◽  
pp. 1376-1385 ◽  
Author(s):  
Feng Hong ◽  
Haiming Cheng ◽  
Chao Song ◽  
Guixia Liu ◽  
Wensheng Yu ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Synthetic Methods ◽  
Red Phosphor ◽  
Light Emitting ◽  
White Leds ◽  
Red Phosphors ◽  
Polygonal Structure ◽  
Warm White Light ◽  
White Light Emitting Diodes

Red phosphors (NH4)2NaInF6:Mn4+ with controllable morphology were synthesized via different synthetic methods, which can be fabricated for warm white LEDs.

Synthesis, structure and luminescence properties of new blue-green-emitting garnet-type Ca3Zr2SiGa2O12:Ce3+ phosphor for near-UV pumped white-LEDs

RSC Advances ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 2155-2161 ◽  
Author(s):  
Jiyou Zhong ◽  
Weidong Zhuang ◽  
Xianran Xing ◽  
Ronghui Liu ◽  
Yanfeng Li ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Luminescence Properties ◽  
Light Emitting ◽  
White Leds ◽  
White Light Emitting Diodes

A new blue-green-emitting garnet-type phosphor Ca3Zr2SiGa2O12:Ce3+ has been explored for n-UV pumped white light-emitting diodes.

scholarly journals Preparation of Bismuth Oxide Photocatalyst and Its Application in White-light LEDs

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Yen-Chang Chu ◽  
Gang-Juan Lee ◽  
Chin-Yi Chen ◽  
Shih-Hsin Ma ◽  
Jerry J. Wu ◽  
...  
Keyword(s):  
Bismuth Oxide ◽  
White Light ◽  
Front Surface ◽  
Color Temperature ◽  
Spray Pyrolysis Method ◽  
Light Emitting ◽  
White Leds ◽  
Air Purifier ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

Bismuth oxide photocatalysts were synthesized and coated on the front surface of phosphor-converted white light-emitting diodes to produce a safe and environmentally benign lighting source. Bismuth oxide photocatalyst powders were synthesized with a spray pyrolysis method at 500°C, 600°C, 700°C, and 800°C. Using the absorption spectrum in the blue and UV regions of the bismuth oxide photocatalysts, the blue light and UV leakage problems of phosphor-converted white LEDs can be significantly reduced. The experimental results showed that bismuth oxide photocatalyst synthesized at 700°C exhibited the most superior spectrum inhibiting ability. The suppressed ratio reached 52.33% in the blue and UV regions from 360 to 420 nm. Related colorimetric parameters and the photocatalyst decomposition ability of fabricated white-light LEDs were tested. The CIE chromaticity coordinates(x,y)were (0.349, 0.393), and the correlated color temperature was 4991 K. In addition, the coating layer of photocatalyst can act as an air purifier and diffuser to reduce glare. A value of66.2±0.60 ppmv of molecular formaldehyde gas can be decomposed in 120 mins.

Eu2+-activated full color orthophosphate phosphors for warm white light-emitting diodes

RSC Advances ◽  
2014 ◽  
Vol 4 (62) ◽  
pp. 33114-33119 ◽  
Author(s):  
Chenglong Zhao ◽  
Zhiguo Xia ◽  
Molin Li
Keyword(s):  
White Light ◽  
Potential Application ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
White Leds ◽  
Full Color ◽  
Warm White Light ◽  
White Light Emitting Diodes

Eu2+-activated full-color versatile orthophosphate phosphors can find potential application in warm white LEDs.

Synthesis of narrow-band red-emitting K2SiF6:Mn4+ phosphors for a deep red monochromatic LED and ultrahigh color quality warm-white LEDs

2015 ◽  
Vol 3 (3) ◽  
pp. 607-615 ◽  
Author(s):  
Ji Hye Oh ◽  
Heejoon Kang ◽  
Yun Jae Eo ◽  
Hoo Keun Park ◽  
Young Rag Do
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Narrow Band ◽  
Light Emitting ◽  
White Leds ◽  
Color Quality ◽  
Warm White Light ◽  
White Light Emitting Diodes

In this study, we synthesized and characterized narrow-band red-emitting K2SiF6:Mn4+ phosphors in order to improve the color qualities of warm white light-emitting diodes (LEDs).

Luminescence Properties and Synthesis of SrMgAl10O17:Mn4+ Red Phosphor for White Light-Emitting Diodes

2016 ◽  
Vol 16 (4) ◽  
pp. 3489-3493 ◽  
Author(s):  
Renping Cao ◽  
Hongdong Xue ◽  
Xiaoguang Yu ◽  
Fen Xiao ◽  
Donglan Wu ◽  
...  
Keyword(s):  
Red Light ◽  
Solid State Reaction Method ◽  
Luminescence Properties ◽  
Conventional Solid State Reaction ◽  
Light Emitting ◽  
White Leds ◽  
Structure Morphology ◽  
Optimal Doping Concentration ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

A series of Mn4+ doped SrMgAl10O17 phosphors are synthesized by a conventional solid-state reaction method in air, and their crystal structure, morphology, and fluorescence properties are investigated. The luminescence properties show clearly that SrMgAl10O17:Mn4+ phosphor can be excited by UV (200–380 nm), near UV (380–420 nm), and blue (420–480 nm) bands of LEDs chip, and emits red light in the range of 600 nm to 750 nm with satisfying CIE chromaticity coordinates (0.7207, 0.2793). The optimal doping concentration of Mn4+ ion is ∼1 mol%, and its lifetime is ∼1.15 ms. The possible luminous mechanism of Mn4+ ion is discussed by Tanabe-Sugano diagram. These experiment results indicate that Mn4+ doped SrMgAl10O17 phosphors can be a potential application as a red-emitting phosphor candidate in white LEDs.

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