Research progress in single host white light emitting phosphor for white LEDs

2011 ◽  
Vol 56 (7) ◽  
pp. 488-503 ◽  
Author(s):  
庆林 郭 ◽  
Ying GUO QingLin WANG ◽  
PanLai LI
Keyword(s):  
White Light ◽  
Research Progress ◽  
Light Emitting ◽  
White Leds ◽  
Single Host

Growth and Light Properties of Fluorescent SiC for White LEDs

2012 ◽  
Vol 717-720 ◽  
pp. 87-92
Author(s):  
Mikael Syväjärvi ◽  
Rositza Yakimova ◽  
Motoaki Iwaya ◽  
Tetsuya Takeuchi ◽  
Isamu Akasaki ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
White Light ◽  
Energy Savings ◽  
Red Light ◽  
Visible Range ◽  
White Led ◽  
Light Emitting ◽  
Blue Led ◽  
White Leds ◽  
New Type

The LED technology started to developed many years ago with red light emitting diodes. To achieve the blue LED, novel growth technologies and process steps were explored, and made it possible to demonstrate efficient blue LED performance from nitrides. The efficiency was further developed and blue LEDs were commercially introduced in the 1990’s. The white LED became possible by the use of the blue LED and a phosphor that converts a part of the blue light to other colors in the visible range to combine into white light. However, even today there are limitations in the phosphor-based white LED technology, in particular for general lighting, and new solutions should be explored to speed the pace when white LEDs will be able to make substantial energy savings. In this paper we overview gallium nitride materials evolution and growth concepts for LEDs. We describe the fluorescent silicon carbide material prepared by a novel growth technology for a new type of white LED in general lighting with pure white light. This paper introduces an interesting research in fundamental growth and optical properties of light emitting silicon carbide.

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.

Color Tuning of Biomass-Derived Carbon Nanodots by Reaction Temperature Toward White Light-Emitting Diodes

NANO ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. 2050159
Author(s):  
Yi Gong ◽  
Yanbing Han ◽  
Fang Zhang ◽  
Mingyue Zhai ◽  
Xing Chen ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
White Light ◽  
Heating Temperature ◽  
Light Emitting Diode ◽  
Peak Position ◽  
Carbon Nanodots ◽  
One Pot ◽  
Light Emitting ◽  
White Leds ◽  
Band Emission

In this work, carbon nanodots (CNDs) were synthesized from extract of mango leaves. Sphere nanodots were formed rapidly by one-step microwave heating. The photoluminescence (PL) of the CNDs was found greatly dependent on the reaction temperature. The emission peak position of the CNDs changed from 550[Formula: see text]nm to 430[Formula: see text]nm when the heating temperature increased from 120[Formula: see text]C to 150[Formula: see text]C. Particularly, the CNDs synthesized at 130[Formula: see text]C showed multi-band emission at 411[Formula: see text]nm, 480[Formula: see text]nm and 530[Formula: see text]nm, providing emitting color from blue to yellow. Moreover, the free chlorophyll molecules in the solution added red fluorescence at 670[Formula: see text]nm, and the integrated emitting color of the CNDs solution was close to white. Coated on a commercial 365[Formula: see text]nm light-emitting diode (LED) chip, the CNDs showed greenish white light with CIE coordinates of (0.37, 0.44). This work provided a one-pot, rapid and green method to obtain multi-emissive CNDs toward white LEDs.

scholarly journals White LEDs: Ultra‐Efficient and High‐Quality White Light‐Emitting Devices using Fluorescent Proteins in Aqueous Medium (Adv. Mater. Technol. 6/2020)

2020 ◽  
Vol 5 (6) ◽  
pp. 2070035
Author(s):  
Sadra Sadeghi ◽  
Rustamzhon Melikov ◽  
Deniz Conkar ◽  
Elif Nur Firat‐Karalar ◽  
Sedat Nizamoglu
Keyword(s):  
Aqueous Medium ◽  
White Light ◽  
Fluorescent Proteins ◽  
High Quality ◽  
Light Emitting ◽  
White Leds ◽  
Light Emitting Devices

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.

Discomfort glare caused by white LEDs having different spectral power distributions

2017 ◽  
Vol 50 (6) ◽  
pp. 921-936 ◽  
Author(s):  
WJ Huang ◽  
Y Yang ◽  
M Ronnier Luo
Keyword(s):  
White Light ◽  
Spectral Power ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
White Leds ◽  
Significant Difference ◽  
Discomfort Glare ◽  
Led Lights ◽  
Green Leds

This paper describes an experiment to investigate discomfort glare caused by white light-emitting diode (LED) lights having different spectral power distributions. It included two groups: a ‘Metamerism’ group and a ‘correlated colour temperatures (CCT)’ group. In the former group, it was found that white lights at 7000 K constructed from different blue LEDs and the same red and green LEDs gave about the same glare perception. In the latter group, there was a significant difference in glare perception between white lights having different CCTs. Finally, glare models, including unified glare rating (UGR) and the newly derived QUGRspd, and mUGRspd models, were tested using the data from the experiment. All of them gave quite accurate predictions of the data.

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.

Facile Preparation and Ultrastable Performance of Single-Component White-Light-Emitting Phosphor-in-Glass used for High-Power Warm White LEDs

2015 ◽  
Vol 7 (51) ◽  
pp. 28122-28127 ◽  
Author(s):  
Xuejie Zhang ◽  
Jinbo Yu ◽  
Jing Wang ◽  
Chenbiao Zhu ◽  
Jinhui Zhang ◽  
...  
Keyword(s):  
White Light ◽  
High Power ◽  
Single Component ◽  
Light Emitting ◽  
White Leds ◽  
Facile Preparation

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.

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