scholarly journals Red Light-Emitting Diodes with All-Inorganic CsPbI3/TOPO Composite Nanowires Color Conversion Films

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Lung-Chien Chen ◽  
Yi-Tsung Chang ◽  
Ching-Ho Tien ◽  
Yu-Chun Yeh ◽  
Zong-Liang Tseng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diode ◽  
Red Light ◽  
Trioctylphosphine Oxide ◽  
Optical And Electrical Properties ◽  
Colloidal Solutions ◽  
High Quality ◽  
Light Emitting ◽  
Hot Injection ◽  
Color Conversion

AbstractThis work presents a method for obtaining a color-converted red light source through a combination of a blue GaN light-emitting diode and a red fluorescent color conversion film of a perovskite CsPbI3/TOPO composite. High-quality CsPbI3 quantum dots (QDs) were prepared using the hot-injection method. The colloidal QD solutions were mixed with different ratios of trioctylphosphine oxide (TOPO) to form nanowires. The color conversion films prepared by the mixed ultraviolet resin and colloidal solutions were coated on blue LEDs. The optical and electrical properties of the devices were measured and analyzed at an injection current of 50 mA; it was observed that the strongest red light intensity was 93.1 cd/m2 and the external quantum efficiency was 5.7% at a wavelength of approximately 708 nm when CsPbI3/TOPO was 1:0.35.

scholarly journals Influence of Surface Passivation on Perovskite CsPbBr1.2I1.8 Quantum Dots and Application of High Purity Red Light-Emitting Diodes

2021 ◽  
Author(s):  
Lung-Chien Chen ◽  
Yen-Hung Tien ◽  
Jianjun Tian
Keyword(s):  
Quantum Dots ◽  
Surface Passivation ◽  
Light Emitting Diode ◽  
Red Light ◽  
Lead Nitrate ◽  
Luminous Efficiency ◽  
Trioctylphosphine Oxide ◽  
Light Emitting ◽  
Co Doped

Abstract In this work, trioctylphosphine oxide (TOPO) ligand is employed to improve the quality of CsPbBr1.2I1.8 quantum dots (QDs) films. Lead nitrate (Pb(NO3)2) is also used to passivate the surface of the films. The study of ligand and surface passivation on the luminous efficiency of red light-emitting diode (LED) is discussed. The CsPbBr1.2I1.8 QDs films co-doped with TOPO and Pb(NO3)2 can effectively improve the performance of the CsPbBr1.2I1.8 QDs LEDs due to reduction of non-radiation recombination of the carriers and smooth morphology in the active layer, thus improving the injection and transportation capabilities of carriers. As a result, the highest luminosity and current efficiency are 502.7 cd/m2 and 0.175 cd/A, respectively.

A high quality liquid-type quantum dot white light-emitting diode

Nanoscale ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 1117-1122 ◽  
Author(s):  
Chin-Wei Sher ◽  
Chin-Hao Lin ◽  
Huang-Yu Lin ◽  
Chien-Chung Lin ◽  
Che-Hsuan Huang ◽  
...  
Keyword(s):  
Quantum Dot ◽  
White Light ◽  
Light Emitting Diode ◽  
White Led ◽  
High Quality ◽  
Light Emitting ◽  
Uv Led ◽  
Liquid Type ◽  
Color Conversion

In this study, a liquid-type QD white LED is demonstrated as an efficient color-conversion layer in UV LED packages.

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.

scholarly journals Red Light-Emitting Diode Based on Blue InGaN Chip with CdTe x S(1 − x) Quantum Dots

2017 ◽  
Vol 12 (1) ◽  
Author(s):  
Rongfang Wang ◽  
Xingming Wei ◽  
Liqin Qin ◽  
Zhihui Luo ◽  
Chunjie Liang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diode ◽  
Red Light ◽  
Light Emitting

scholarly journals Effect of Excitation Wavelength on Optical Performances of Quantum-Dot-Converted Light-Emitting Diode

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1100 ◽  
Author(s):  
Caiman Yan ◽  
Xuewei Du ◽  
Jiasheng Li ◽  
Xinrui Ding ◽  
Zongtao Li ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Red Light ◽  
Energy Utilization ◽  
Excitation Wavelength ◽  
Color Gamut ◽  
High Quality ◽  
Light Emitting ◽  
Color Quality ◽  
General Guide ◽  
Rgb System

Light-emitting diode (LED) combined with quantum dots (QDs) is an important candidate for next-generation high-quality semiconductor devices. However, the effect of the excitation wavelength on their optical performance has not been fully explored. In this study, green and red QDs are applied to LEDs of different excitation wavelengths from 365 to 455 nm. The blue light is recommended for exciting QDs from the perspective of energy utilization. However, QD LEDs excited at 365 nm have unique advantages in eliminating the original peaks from the LED chip. Moreover, the green or red light excited by ultraviolet light has an advantage in colorimetry. Even for the 455 nm LED with the highest QD concentration at 7.0 wt%, the color quality could not compete with the 365 nm LED with the lowest QD concentration at 0.2 wt%. A 117.5% (NTSC1953) color gamut could be obtained by the 365 nm-excited RGB system, which is 32.6% higher than by the 455 nm-excited solution, and this can help expand the color gamut of LED devices. Consequently, this study provides an understanding of the properties of QD-converted LEDs under different wavelength excitations, and offers a general guide to selecting a pumping source for QDs.

Patterned mist deposition of tri-colour CdSe/ZnS quantum dot films toward RGB LED devices

2012 ◽  
Vol 20 (2) ◽  
Author(s):  
S. Pickering ◽  
A. Kshirsagar ◽  
J. Ruzyllo ◽  
J. Xu
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Precursor Solution ◽  
Colloidal Quantum Dots ◽  
Colloidal Solutions ◽  
Light Emitting ◽  
Mist Deposition ◽  
Viable Method

AbstractIn this experiment a technique of mist deposition was explored as a way to form patterned ultra-thin-films of CdSe/ZnS core/shell nanocrystalline quantum dots using colloidal solutions. The objective of this study was to investigate the feasibility of mist deposition as a patterning method for creating multicolour quantum dot light emitting diodes. Mist deposition was used to create three rows of quantum dot light emitting diodes on a single device with each row having a separate colour. The colours chosen were red, green and yellow with corresponding peak wavelengths of 620 nm, 558 nm, and 587 nm. The results obtained from this experiment show that it is possible to create multicolour devices on a single substrate. The peak brightnesses obtained in this experiment for the red, green, and yellow were 508 cd/m, 507 cd/m, and 665 cd/m, respectively. The similar LED brightness is important in display technologies using colloidal quantum dots in a precursor solution to ensure one colour does not dominate the emitted spectrum. Results obtained in-terms of brightness were superior to those achieved with inkjet deposition. This study has shown that mist deposition is a viable method for patterned deposition applied to quantum dot light emitting diode display technologies.

scholarly journals Study on the Color-Compensation Effect of Composite Orange-Red Quantum Dots in WLED Application

2020 ◽  
Author(s):  
Xiaoyue Hu ◽  
Yangyang Xie ◽  
Chong Geng ◽  
Shu Xu ◽  
Wengang Bi
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diode ◽  
Red Light ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Light Emitting ◽  
Light Region ◽  
Color Compensation ◽  
Donor Acceptor ◽  
Color Rendering

Abstract Quantum dots (QDs) as emerging light-converting materials show the advantage of enhancing color quality of white light-emitting diode (WLED). However, WLEDs employing narrow-emitting monochromic QDs usually present unsatisfactory color rendering in the orange region. Herein, composite orange-red QDs (composite-QDs) are developed through mixing CdSe/ZnS based orange QDs (O-QDs) and red QDs (R-QDs) to compensate the orange-red light for WLEDs. We investigated the effect of self-absorption and fluorescence resonance energy transfer (FRET) process in composite-QDs on the spectral controllability and fluorescent quenching in WLEDs. The concentration and donor/acceptor ratios were also taken into account to analyze the FRET efficiency and help identify suitable composite-QDs for color compensation in the orange-red light region. As the result, the optimized composite-QDs effectively improve the color rendering index of the WLED compared with monochromatic QDs.

scholarly journals White Light Electroluminescence by Organic-Inorganic Heterostructures with CdSe Quantum Dots as Red Light Emitters

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Ilker Oner ◽  
Elias Stathatos ◽  
Canan Varlikli
Keyword(s):  
Quantum Dots ◽  
Light Emission ◽  
Red Light ◽  
Conductive Polymer ◽  
Host Material ◽  
Trioctylphosphine Oxide ◽  
Cdse Quantum Dots ◽  
Light Emitters ◽  
Emission Layer ◽  
Light Emitting

We have developed a white organic light-emitting diode featuring a double emission layer comprising a blue light-emitting conductive polymer as a host material for Cadmium Selenide (CdSe) quantum dots as red light emitters and tris-(8-hydroxyquinoline) aluminium thin layer for green light emission. The Commission Internationale de l'Eclairage coordinates of the emitting light of the device were found to be (0.32, 0.40) which were only slightly changed over a range of applied voltages between 5 and 10 volts. The use of CdSe nanocrystalline quantum dots (surface-stabilized with hexadecylamine/trioctylphosphine oxide ligands) in the hybrid heterostructure with poly(9,9-di-n-octylfluorenyl-2,7-diyl) conductive polymer was studied for a variety of CdSe concentrations developing the performance of the device in means of overcoming segregation problems in the blend. Besides, constituents' ratio was further examined for the exploration of possible energy transfer from polymer host material to the CdSe quantum dots as a key factor for well-balanced emission in the electroluminescent devices.

Study on the Color-Compensation Effect of Hybrid Orange-Red Quantum Dots in WLED Application

2020 ◽  
Author(s):  
Xiaoyue Hu ◽  
Yangyang Xie ◽  
Chong Geng ◽  
Shu Xu ◽  
Wengang Bi
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diode ◽  
Red Light ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Light Emitting ◽  
Light Region ◽  
Color Compensation ◽  
Donor Acceptor ◽  
Color Rendering

Abstract Quantum dots (QDs) as emerging light-converting materials show the advantage of enhancing color quality of white light-emitting diode (WLED). However, WLEDs employing narrow-emitting monochromic QDs usually present unsatisfactory color rendering in the orange region. Herein, orange-red emitting polychromic hybrid QDs (hybrid-QDs) are developed through mixing CdSe/ZnS based orange QDs (O-QDs) and red QDs (R-QDs) to compensate the orange-red light for WLEDs. We investigated the effect of self-absorption and fluorescence resonance energy transfer (FRET) process in hybrid-QDs on the spectral controllability and fluorescent quenching in WLEDs. The concentration and donor/acceptor ratios were also taken into account to analyze the FRET efficiency and help identify suitable hybrid-QDs for color compensation in the orange-red light region. As the result, the optimized hybrid-QDs effectively improve the color rendering index of the WLED compared with monochromatic QDs at the same color coordinates.

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