scholarly journals High Stability of Liquid-Typed White Light-Emitting Diode with Zn0.8Cd0.2S White Quantum Dots

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 415
Author(s):  
Chin-Chuan Huang ◽  
Kuo-Hsiung Chu ◽  
Chin-Wei Sher ◽  
Chun-Liang Lin ◽  
Yan-Kuin Su ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
High Stability ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Luminous Efficiency ◽  
Color Temperature ◽  
Chemical Route ◽  
Light Emitting ◽  
The Stability

In this study, we demonstrate a new design of white light-emitting diode (WLED) with high stability and luminous efficiency as well as positive aging. Colloidal ternary Zn0.8Cd0.2S (named Zn0.8) white quantum dots (WQDs) were prepared by chemical route and dispersed in xylene, integrating them into an ultraviolet light-emitting diode (UV-LED) to form WQD-white light emitting diode (WQD-WLED). High efficiency, high color quality and excellent reliability of WQD-WLED with neutral white correlated color temperature (CCT) can be obtained. The experimental results indicate that the stability of relative luminous efficiency and color rendering index (CRI) of the WQD-WLED can reach up to 160 and 82%, respectively. Moreover, the WQD-WLED can operate more than 1000 h under 100 mA, and the quantity of WQDs in the glass package can be reduced.

scholarly journals High Efficiency and Color Rendering Quantum Dots White Light Emitting Diodes Optimized by Luminescent Microspheres Incorporating

Nanophotonics ◽  
2016 ◽  
Vol 5 (4) ◽  
pp. 565-572 ◽  
Author(s):  
Wei Chen ◽  
Kai Wang ◽  
Junjie Hao ◽  
Dan Wu ◽  
Jing Qin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
High Efficiency ◽  
Lattice Structure ◽  
Light Emitting Diode ◽  
Luminescent Properties ◽  
Color Temperature ◽  
High Quantum Efficiency ◽  
Light Emitting ◽  
Color Rendering

AbstractIn this research, we have developed an approach by incorporating quantum dots (QDs) with red emission into mesoporous silica microspheres through a non-chemical process and obtained luminescent microspheres (LMS). Owing to the lattice structure of LMS, QDs were effectively protected from intrinsic aggregation in matrix and surface deterioration by encapsulant, oxygen and moisture. The LMS composite has therefore maintained large extent luminescent properties of QDs, espe-cially for the high quantum efficiency. Moreover, the fabricated white light emitting diode (WLED) utilizing LMS and YAG:Ce yellow phosphor has demonstrated excellent light performance with color coordinates around (x = 0.33, y = 0.33), correlated color temperature between 5100 and 5500 K and color rendering index of Ra = 90, R9 = 95. The luminous efficiency of the WLED has reached up to a new record of 142.5 lm/W at 20 mA. LMS provide a promising way to practically apply QDs in lightings and displays with high efficiency as well as high stability.

Highly luminescent and stable white light-emitting diodes created by direct incorporation of Cd-free quantum dots in silicone resins using the thiol group

2015 ◽  
Vol 3 (26) ◽  
pp. 6908-6915 ◽  
Author(s):  
Cheolsang Yoon ◽  
Taewoo Kim ◽  
Min-Ho Shin ◽  
Young-Geon Song ◽  
Kyusoon Shin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
High Stability ◽  
Light Emitting Diodes ◽  
Thiol Group ◽  
Luminous Efficiency ◽  
Light Emitting ◽  
White Light Emitting Diodes ◽  
Color Conversion ◽  
Direct Incorporation

WLEDs fabricated by direct incorporation of QDs into silicone resins using the thiol group exhibit enhanced color conversion and luminous efficiency with high stability.

Stable CsPbX3@SiO2 Perovskite Quantum Dots for White-Light Emitting Diodes

2020 ◽  
Vol 15 (5) ◽  
pp. 599-606
Author(s):  
Jian Xu ◽  
Hongxiang Zhang ◽  
Chunxia Wu ◽  
Jun Dai
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Synthesis Method ◽  
Water Contact ◽  
Light Emitting ◽  
Perovskite Quantum Dots ◽  
The Stability ◽  
White Light Emitting Diodes

In this article, we reported the synthesis method of stable CsPbX3@SiO2 quantum dots using cesium acetate instead of cesium carbonate. The results showed that CsPbX3@SiO2 presents good crystallinity and excellent luminescence properties. The coating layer of SiO2 on the CsPbX3 quantum dots surface blocks the air and water contact and suppresses anion exchange between the quantum dots, which dramatically enhances the stability. White light-emitting diode devices are manufactured by integrating the green CsPbBr3@SiO2 quantum dots and red CsPbBr1 I2@SiO2 quantum dots on the blue GaN chips. The devices show stable white light emission with Commission Internationale de L'Eclairage color coordinates (0.3511, 0.3437), and the white light intensity keeps unchanged after continuously working for 16 hours. The results indicate that CsPbX3@SiO2 quantum dots can be an ideal down-conversion fluorescent material for white light-emitting diode devices.

scholarly journals Ultrawide Color Gamut Perovskite and CdSe/ZnS Quantum-Dots-Based White Light-Emitting Diode with High Luminous Efficiency

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1314 ◽  
Author(s):  
Chih-Hao Lin ◽  
Chieh-Yu Kang ◽  
Akta Verma ◽  
Tingzhu Wu ◽  
Yung-Min Pai ◽  
...  
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Red Light ◽  
Color Gamut ◽  
Television System ◽  
Light Emitting ◽  
Term Operation ◽  
Liquid Type

We demonstrate excellent color quality of liquid-type white light-emitting diodes (WLEDs) using a combination of green light-emitting CsPbBr3 and red light-emitting CdSe/ZnS quantum dots (QDs). Previously, we reported red (CsPbBr1.2I1.8) and green (CsPbBr3) perovskite QDs (PQDs)-based WLEDs with high color gamut, which manifested fast anion exchange and stability issues. Herein, the replacement of red PQDs with CdSe/ZnS QDs has resolved the aforementioned problems effectively and improved both stability and efficiency. Further, the proposed liquid-type device possesses outstanding color gamut performance (132% of National Television System Committee and 99% of Rec. 2020). It also shows a high efficiency of 66 lm/W and an excellent long-term operation stability for over 1000 h.

Solution-Processed White Light-Emitting Diode Utilizing Hybrid Polymer and Red–Green–Blue Quantum Dots

2012 ◽  
Vol 51 ◽  
pp. 09MH03
Author(s):  
Byoung Wook Kwon ◽  
Dong Ick Son ◽  
Dong-Hee Park ◽  
Heon-Jin Choi ◽  
Won-Kook Choi
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emitting Diode ◽  
Hybrid Polymer ◽  
Solution Processed ◽  
Light Emitting

scholarly journals Near Unity PLQY and High Stability of Barium Thiocyanate Based All-Inorganic Perovskites and Their Applications in White Light-Emitting Diodes

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 209
Author(s):  
Gopi Chandra Adhikari ◽  
Saroj Thapa ◽  
Yang Yue ◽  
Hongyang Zhu ◽  
Peifen Zhu
Keyword(s):  
White Light ◽  
Large Scale ◽  
Light Emitting Diode ◽  
Photophysical Properties ◽  
Environmental Stability ◽  
Color Temperature ◽  
Ambient Atmosphere ◽  
Light Emitting ◽  
Halide Perovskite ◽  
Lead Halide

All-inorganic lead halide perovskite (CsPbX3) nanocrystals (NCs) have emerged as a highly promising new generation of light emitters due to their extraordinary photophysical properties. However, the performance of these semiconducting NCs is undermined due to the inherent toxicity of lead and long-term environmental stability. Here, we report the addition of B-site cation and X-site anion (pseudo-halide) concurrently using Ba(SCN)2 (≤50%) in CsPbX3 NCs to reduce the lead and improve the photophysical properties and stability. The as-grown particles demonstrated an analogous structure with an almost identical lattice constant and a fluctuation of particle size without altering the morphology of particles. Photoluminescence quantum yield is enhanced up to near unity (~98%) by taking advantage of concomitant doping at the B- and X-site of the structure. Benefitted from the defect reductions and stronger bonding interaction between Pb2+ and SCN− ions, Ba(SCN)2-based NCs exhibit improved stability towards air and moisture compared to the host NCs. The doped NCs retain higher PLQY (as high as seven times) compared to the host NCs) when stored in an ambient atmosphere for more than 176 days. A novel 3D-printed multiplex color conversion layer was used to fabricate a white light-emitting diode (LED). The obtained white light shows a correlated color temperature of 6764 K, a color rendering index of 87, and luminous efficacy of radiation of 333 lm/W. In summary, this work proposes a facile route to treat sensitive lead halide perovskite NCs and to fabricate LEDs by using a low-cost large-scale 3-D printing method, which would serve as a foundation for fabricating high-quality optoelectronic devices for near future lighting technologies.

scholarly journals Use of Hybrid PEDOT:PSS/Metal Sulfide Quantum Dots for a Hole Injection Layer in Highly Efficient Green Phosphorescent Organic Light-Emitting Diodes

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenqing Zhu ◽  
Kuangyu Ding ◽  
Chen Yi ◽  
Ruilin Chen ◽  
Bin Wei ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Metal Sulfide ◽  
Molybdenum Sulfide ◽  
Hole Injection ◽  
Light Emitting ◽  
Hole Injection Layer ◽  
Highly Efficient ◽  
Organic Light

In this study, we have synthesized the molybdenum sulfide quantum dots (MoS2 QDs) and zinc sulfide quantum dots (ZnS QDs) and demonstrated a highly efficient green phosphorescent organic light-emitting diode (OLED) with hybrid poly (3,4-ethylenedioxythiophene)/poly (styrenesulfonate) (PEDOT:PSS)/QDs hole injection layer (HIL). The electroluminescent properties of PEDOT:PSS and hybrid HIL based devices were explored. An optimized OLED based on the PEDOT:PSS/MoS2 QDs HIL exhibited maximum current efficiency (CE) of 72.7 cd A−1, which shows a 28.2% enhancement as compared to counterpart with single PEDOT:PSS HIL. The higher device performance of OLED with hybrid HIL can be attributed to the enhanced hole injection capacity and balanced charge carrier transportation in the OLED devices. The above analysis illustrates an alternative way to fabricate the high efficiency OLEDs with sulfide quantum dots as a HIL.

Developed one-pot synthesis of dual-color CdSe quantum dots for white light-emitting diode application

2018 ◽  
Vol 6 (12) ◽  
pp. 3089-3096 ◽  
Author(s):  
Sheng Dai ◽  
Cyuan-Bin Siao ◽  
Shu-Ru Chung ◽  
Kuan-Wen Wang ◽  
Xiaoqing Pan
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emitting Diode ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
One Pot ◽  
Synthetic Process ◽  
Light Emitting ◽  
One Pot Synthesis ◽  
Enhanced Stability

The size and fraction of red and green CdSe QDs can be controlled precisely during the synthetic process, thus manifesting remarkably enhanced stability.

scholarly journals Chromaticity Study of Curcumin Dye Extracted from Curcuma longa L. Using for UV Light down Conversion for White Light Emitting Diode

2019 ◽  
Vol 290 ◽  
pp. 183-189
Author(s):  
Mahmood Al Shafouri ◽  
Naser Mahmoud Ahmed ◽  
Zainuriah Hassan ◽  
Munirah Abdullah Almessiere
Keyword(s):  
White Light ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Curcuma Longa ◽  
Color Temperature ◽  
Light Emitting ◽  
Chromaticity Coordinates ◽  
Major Factors ◽  
Color Rendering ◽  
Down Conversion

In thus study, Turmeric phosphor dye was extracted from Curcuma Longa L. via a simple technique using silica gel. The phosphor was used for light down-conversion of UV light for the manufacture white light emitting diode (WLED). The UV-LED was analyzed over 395nm wavelengths. The characteristics of the white light chromaticity were controlled by tuning the current and phosphor concentration. An optimum color rendering index (CRI) value of 63.4 was obtained. The chromaticity coordinates (CIE) and correlated color temperature (CCT) were measured for various currents and phosphor concentrations. The white phosphor exhibited CIE value of 0.355,0.338 and CCT of 4567 K. The concentration of phosphor and amount of applied current were confirmed to be major factors that control the intensity of white light emitted from the sample, where CIE and CRI of the emitted light steadily increased with the concentration of phosphor and current. Thus, phosphor concentration has a critical effect on conversion efficiency. Key words: Turmeric, phosphor, WLED, curcumin

All-solution processed inverted green quantum dot light-emitting diodes with concurrent high efficiency and long lifetime

2019 ◽  
Vol 6 (10) ◽  
pp. 2009-2015 ◽  
Author(s):  
Zhiwen Yang ◽  
Qianqian Wu ◽  
Gongli Lin ◽  
Xiaochuan Zhou ◽  
Weijie Wu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Shell Growth ◽  
Solution Processed ◽  
Light Emitting ◽  
Long Lifetime

An all-solution processed inverted green quantum dot-based light-emitting diode with concurrent high efficiency and long lifetime is obtained by precisely controlled double shell growth of quantum dots.

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