Highly efficient white light-emitting diodes with a bi-component emitting layer based on blue and yellow thermally activated delayed fluorescence emitters

2018 ◽  
Vol 6 (12) ◽  
pp. 2951-2956 ◽  
Author(s):  
Yongzhen Chen ◽  
Shengyong Li ◽  
Taiping Hu ◽  
Xiaofang Wei ◽  
Zhiyi Li ◽  
...  

A white LED with a bi-component light emitting layer is reported providing white light emission with a CIE of (0.38, 0.40), a CRI of 71, and a maximum EQE of 12.5%. These are among the best for bi-component based devices.

2013 ◽  
Vol 1538 ◽  
pp. 371-375
Author(s):  
Zhao Si ◽  
Tongbo Wei ◽  
Jun Ma ◽  
Ning Zhang ◽  
Zhe Liu ◽  
...  

ABSTRACTA study about the achievement of dichromatic white light-emitting diodes (LEDs) was performed. A series of dual wavelength LEDs with different last quantum-well (LQW) structure were fabricated. The bottom seven blue light QWs (close to n-GaN layer) of the four samples were the same. The LQW of sample A was 3 nm, and that of sample B, C and D were 6 nm, a special high In content ultra-thin layer was inserted in the middle of the LQW of sample C and on top of that of sample D. XRD results showed In concentration fluctuation and good interface quality of the four samples. PL measurements showed dual wavelength emitting, the blue light peak position of the four samples were almost the same, sample A with a narrower LQW showed an emission wavelength much shorter than that of sample B, C, D. EL measurement was done at an injection current of 100 mA. Sample A only showed LQW emission due to holes distribution. Because of wider LQW, the emission wavelength of sample B, C and D was longer and peak intensity was weaker. Sample D with insert layer on top of LQW showed strongest yellow light emission with a blue peak. As the injection current increased, sample A showed highest output light power due to narrower LQW. Of the other three samples with wider LQW, sample D showed highest output power. Effective yellow light emission has always been an obstacle to the achievement of dichromatic white LED. Sample D with insert layer close to p-GaN can confine the hole distribution more effectively hence the recombination of holes and electrons was enhanced, the yellow light emission was improved and dichromatic white LED was achieved.


2019 ◽  
Vol 7 (11) ◽  
pp. 3146-3149 ◽  
Author(s):  
Yuki Kato ◽  
Hisahiro Sasabe ◽  
Yuya Hayasaka ◽  
Yuichiro Watanabe ◽  
Hiroki Arai ◽  
...  

A pyradine-containing sky blue fluorescent emitter can achieve efficient white light emission through in situ metal complex formation.


RSC Advances ◽  
2016 ◽  
Vol 6 (97) ◽  
pp. 95055-95061 ◽  
Author(s):  
Kaushik Das ◽  
Archis Marathe ◽  
Xianwen Zhang ◽  
Zhi Zhao ◽  
Jharna Chaudhuri

White light was obtained by successful blending of blue, green, orange and red emissions from tri-doped YBO3.


2019 ◽  
Vol 48 (40) ◽  
pp. 14966-14970 ◽  
Author(s):  
Ce Wang ◽  
Zheng Yin ◽  
Wei-Min Ma ◽  
Xi-Yao Li ◽  
Li-Hui Cao ◽  
...  

A white light MOF was constructed from low-cost 1,3,5-benzenetricarboxylate and nontoxic Zinc(ii) ions, which exhibited near sunlight continuous white-light emission under a wide radiation range of 300 to 390 nm and was used for white-light emitting diodes.


2010 ◽  
Vol 93 (11) ◽  
pp. 3857-3861 ◽  
Author(s):  
B.V. Ratnam ◽  
M. Jayasimhadri ◽  
Kiwan Jang ◽  
Ho Sueb Lee ◽  
Soung-Soo Yi ◽  
...  

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