White LED Packaging with Layered Encapsulation of Quantum Dots and Optical Properties

Kwak, Seong Kwon; Yoo, Tae Wook; Kim, Bosung; Lee, Sang Mun; Lee, Yun Su; Park, Lee Soon

doi:10.1080/15421406.2012.690655

Cited by 7 publications

(3 citation statements)

References 11 publications

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“…Throughout all the processing steps, there are many critical aspects that need to be further optimized in order to increase the light emission performances. They include: the surface chemistry properties at the interface between the QDs and polymeric matrix to avoid agglomeration and reduction of QD emission efficiency [ 122 , 123 ], the right mixture of different QDs components to achieve high-color rendering ability [ 124 , 125 , 126 ] and the encapsulation matrix able to protect the chip and to prolong its lifetime [ 127 , 128 ]. For an overview on the main strategies reported in literature, in particular for highly efficient white-light LED, refer to the recent review written by Xie and colleagues [ 129 ].…”

Section: Use Of Qds For Light Emission Applicationsmentioning

confidence: 99%

Engineering of Semiconductor Nanocrystals for Light Emitting Applications

et al. 2016

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Semiconductor nanocrystals are rapidly spreading into the display and lighting markets. Compared with liquid crystal and organic LED displays, nanocrystalline quantum dots (QDs) provide highly saturated colors, wide color gamut, resolution, rapid response time, optical efficiency, durability and low cost. This remarkable progress has been made possible by the rapid advances in the synthesis of colloidal QDs and by the progress in understanding the intriguing new physics exhibited by these nanoparticles. In this review, we provide support to the idea that suitably engineered core/graded-shell QDs exhibit exceptionally favorable optical properties, photoluminescence and optical gain, while keeping the synthesis facile and producing QDs well suited for light emitting applications. Solid-state laser emitters can greatly profit from QDs as efficient gain materials. Progress towards fabricating low threshold, solution processed DFB lasers that are optically pumped using one- and two-photon absorption is reviewed. In the field of display technologies, the exploitation of the exceptional photoluminescence properties of QDs for LCD backlighting has already advanced to commercial levels. The next big challenge is to develop the electroluminescence properties of QD to a similar state. We present an overview of QLED devices and of the great perspectives for next generation display and lighting technologies.

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Section: Use Of Qds For Light Emission Applicationsmentioning

confidence: 99%

Engineering of Semiconductor Nanocrystals for Light Emitting Applications

et al. 2016

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“…Numerous recent studies have focused on enhancing lighting performance of WLED packages with in-cup or conformal phosphor design by non-integrating * E-mail: leehy@nkust.edu.tw or integrating one diffusional particle into a yellow YAG:Ce 3+ phosphor compound, for example, adding SiO 2 [8,9] or using Y 2 O 3 :Eu 3+ [10]. In 2012, Kwak et al [11,12] added red quantum dots to YAG phosphor by layerby-layer mode for improving the luminous flux and the color rendering index (CRI) of WLEDs. On the other hand, the WLED remote-phosphor structure, in which the phosphor layer and the LED chip are separated from each other, may reduce the absorption ability of the re-emitted light by the LED chip, leading to a better performance of utilized phosphor materials [13,14].…”

Section: Introductionmentioning

confidence: 99%

Enhancement of color quality and luminous flux for remote-phosphor LEDs with red-emitting CaMgSi₂O₆:Eu²⁺,Mn²⁺

Luo¹,

Loan²,

Tho

et al. 2020

Materials Science-Poland

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SiO2 particles and red-emitting CaMgSi2O6:Eu2+,Mn2+ phosphor have been added into a yellow phosphor compound YAG:Ce3+ to enhance the optical efficiency of white light LEDs whose average correlated color temperature (CCT) is in the range of 5600 K ÷ 8500 K. It was observed that altering CaMgSi2O6:Eu2+,Mn2+ concentration from 2 % to 30 % while maintaining 5 % of the SiO2 strongly influenced the color rendering index (CRI), color quality scale (CQS), and lumen efficiency of the compound. Besides, through the application of Monte Carlo simulation and Mie-scattering theory, it was possible to improve the optical properties by CaMgSi2O6:Eu2+,Mn2+ and SiO2 addition. The results provided a practical approach to achieve higher luminous efficiency and better color uniformity in remote-phosphor white LEDs (RP-WLEDs).

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“…These red-emitting phosphors, such as CaAlSiN 3 :Eu 2+ , Y 2 O 2 S:Eu 3+ , etc., were seen as a good bet. , The proposed phosphors have improved the color rendering index (CRI) of the combination but at the expense of the efficacy, while QDs could not be employed because of its low stability. To overcome this, QDs have been successfully embedded in a polymer encapsulant, − silica, and glass matrix. − A few of these encapsulation techniques were employed in WLED packaging, and comparative studies have been carried out. − The mixtures of YAG:Ce 3+ phosphor along with red components have consistently proven to yield lower efficiency, despite providing desired CRI as a result of reabsorption …”

Section: Introductionmentioning

confidence: 99%

Stacked Quantum Dot Embedded Silica Film on a Phosphor Plate for Superior Performance of White Light-Emitting Diodes

Sohn

Unithrattil

2014

ACS Appl. Mater. Interfaces

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Application of quantum dots as a color converter in white light-emitting diodes (WLEDs) has been highly restrained because of its lower stability under the operating conditions of LEDs. The feasibility of using quantum dots in WLEDs has been studied and demonstrated by developing a non-conventional packing technique. Multiple core shell CuInS2/ZnS quantum dots were coated by silica, and the silica-coated quantum dots were dispersed in ethoxylated trimethylolpropane triacrylate to form a color conversion film. This along with phosphor in a glass plate made of Y3Al5O12:Ce(3+) phosphor was stacked in different configurations, and its effect on color rendering of WLEDs was studied. In addition, the configuration developed here protects the color converter from thermal strain and moisture.

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White LED Packaging with Layered Encapsulation of Quantum Dots and Optical Properties

Cited by 7 publications

References 11 publications

Engineering of Semiconductor Nanocrystals for Light Emitting Applications

Engineering of Semiconductor Nanocrystals for Light Emitting Applications

Enhancement of color quality and luminous flux for remote-phosphor LEDs with red-emitting CaMgSi₂O₆:Eu²⁺,Mn²⁺

Stacked Quantum Dot Embedded Silica Film on a Phosphor Plate for Superior Performance of White Light-Emitting Diodes

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White LED Packaging with Layered Encapsulation of Quantum Dots and Optical Properties

Cited by 7 publications

References 11 publications

Engineering of Semiconductor Nanocrystals for Light Emitting Applications

Engineering of Semiconductor Nanocrystals for Light Emitting Applications

Enhancement of color quality and luminous flux for remote-phosphor LEDs with red-emitting CaMgSi2O6:Eu2+,Mn2+

Stacked Quantum Dot Embedded Silica Film on a Phosphor Plate for Superior Performance of White Light-Emitting Diodes

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Product

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Enhancement of color quality and luminous flux for remote-phosphor LEDs with red-emitting CaMgSi₂O₆:Eu²⁺,Mn²⁺