Color-tunable multilayer light-emitting diodes based on conjugated polymers

2004 ◽  
Vol 84 (7) ◽  
pp. 1195-1197 ◽  
Author(s):  
C. C. Huang ◽  
H. F. Meng ◽  
G. K. Ho ◽  
C. H. Chen ◽  
C. S. Hsu ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Color Tunable

Light-Emitting Diodes from Fluorene-Based π-Conjugated Polymers

2000 ◽  
Vol 12 (7) ◽  
pp. 1931-1936 ◽  
Author(s):  
Anne Donat-Bouillud ◽  
Isabelle Lévesque ◽  
Ye Tao ◽  
Marie D'Iorio ◽  
Serge Beaupré, ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Light Emitting Diodes ◽  
Light Emitting

Light-Emitting Diodes Based on Conjugated Polymers: Control of Colour and Efficiency

1992 ◽  
Vol 247 ◽  
Author(s):  
Paul L. Burn ◽  
A. B. Holmes ◽  
A. Kraft ◽  
A. R. Brown ◽  
D. D. C. Bradley ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Conjugated Polymers ◽  
Light Emitting Diodes ◽  
Fold Increase ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Metal Contacts ◽  
Light Emitting ◽  
Lithographic Patterning ◽  
Energy Gaps

ABSTRACTStudies of the effect of different electrode combinations on the device characteristics of simple three layer light-emitting diodes (LEDs) prepared with poly(ρ-phenylenevinylene) (PPV) as the emissive layer sandwiched between two metal contacts have shown that it is generally more difficult to inject electrons than holes. In order to improve the efficiency of such devices it is, therefore, necessary to develop methods to enhance the injection of electrons and we illustrate here one example where we have successfully achieved this by the introduction of a further, electron transport, layer. The result is an eight fold increase in efficiency over our best three layer PPV devices. The efficiency is also dependent on the details of the polymer electronic structure and using a family of copolymers we have been able to produce enhancements in efficiency to values of up to 30 times that of the corresponding PPV devices. Variations in the polymer electronic structure also affect the colour of emission and the same family of copolymers allow control of emission colour from blue/green to orange/red. Supramolecular control of the copolymer electronic structure can be achieved by lithographic patterning and we show that it is possible to produce regions within a single polymer film that possess different π-π* energy gaps.

scholarly journals Side-chain conjugated polymers for use in the active layers of hybrid semiconducting polymer/quantum dot light emitting diodes

2016 ◽  
Vol 7 (1) ◽  
pp. 101-112 ◽  
Author(s):  
Ana Fokina ◽  
Yeonkyung Lee ◽  
Jun Hyuk Chang ◽  
Lydia Braun ◽  
Wan Ki Bae ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Conjugated Polymers ◽  
Light Emitting Diodes ◽  
Side Chain ◽  
Hybrid Polymer ◽  
Semiconducting Polymer ◽  
Light Emitting ◽  
Active Layers

Three monomers,M1–M3, with modified carbazole cores and styrene functionality were polymerized by RAFT. The polymers were then used in the active layers of hybrid polymer/quantum dot light emitting diodes.

Color tunable Eu-doped CaSrNb2O7 phosphors for white light-emitting diodes and optical thermometers

2020 ◽  
Vol 227 ◽  
pp. 117582
Author(s):  
Qianchao Ma ◽  
Qihu Li ◽  
Guangqing Zhang ◽  
Shuiquan Han ◽  
Qianxin Zhang ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Color Tunable ◽  
White Light Emitting Diodes

Transparent bi-directional organic light-emitting diodes with color-tunable top emission

2020 ◽  
Vol 86 ◽  
pp. 105900
Author(s):  
Gunel Huseynova ◽  
Jae-Hyun Lee ◽  
Yong Hyun Kim ◽  
Jonghee Lee
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light ◽  
Color Tunable

scholarly journals Color tunable light-emitting diodes based on p+-Si/p-CuAlO2/n-ZnO nanorod array heterojunctions

2010 ◽  
Vol 97 (1) ◽  
pp. 013101 ◽  
Author(s):  
Bo Ling ◽  
Jun Liang Zhao ◽  
Xiao Wei Sun ◽  
Swee Tiam Tan ◽  
Aung Ko Ko Kyaw ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Nanorod Array ◽  
Zno Nanorod ◽  
Light Emitting ◽  
Color Tunable ◽  
Zno Nanorod Array

Variable band gap conjugated polymers for optoelectronic and redox applications

2005 ◽  
Vol 20 (12) ◽  
pp. 3188-3198 ◽  
Author(s):  
Young-Gi Kim ◽  
Barry C. Thompson ◽  
Nisha Ananthakrishnan ◽  
G. Padmanaban ◽  
S. Ramakrishnan ◽  
...  
Keyword(s):  
Phase Separation ◽  
Conjugated Polymers ◽  
Band Gap ◽  
Conjugated Polymer ◽  
Narrow Band ◽  
Acid Methyl Ester ◽  
Light Emitting ◽  
Donor And Acceptor ◽  
Color Tunable ◽  
Variable Band Gap

We report here on the utilization of variable band gap conjugated polymers for optoelectronic redox applications comprising organic photovoltaics, color tunable light emitting diodes, and electrochromics. For the evaluation of morphology in photovoltaicdevices, atomic force microscopy, and optical microscopy provided direct visualization of the blend film structure. The evolution of the morphology in two and three component blends incorporating poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenlenevinylene] (MEH-PPV), poly(methylmethacrylate) (PMMA), and [6, 6]-phenyl C61-butyric acid methyl ester (PCBM) was investigated. It was found that while insulating PMMA can be used to modulate the phase separation in these blends, a bicontinuous network of donor and acceptor was required to achieve the best device results. Similarily, a MEH-PPVcopolymer with a decreased conjugation length has been used for investigating inter- and intramolecular photoinduced charge transfer in the presence of PMMA and PCBM.We fabricated MEH-PPV/PCBM solar cells that have power conversion efficiencies up to 1.5% with a range of 0.7–1.5%, dependent on the nature of the MEH-PPV used. This further indicates that in addition to blend morphology, polymer structure is critical for optimizing device performance. To this end, the concept of an ideal donor for photovoltaic devices based on poly[2,5-di(3,7-dialkoxy)-cyanoterephthalylidene] is described and two donor-acceptor polymers based on cyanovinylene (CNV) and dioxythiophene are discussed as representative examples of soluble narrow band gap polymers synthesized in our group. For light emitting applications, utilization of two blue emitting conjugated polymers poly (9,9-dioctylfluorene) (PFO) and poly[(9,9-dihexylfluorenyl-2,7-diyl)-co-(9,ethyl-3,6-carbazole)] (PFH-PEtCz)is presented for a color tunable polymer light emitting diode that emits orange, green, and blue light with a voltage range of 7–10 V as a function of the total conjugated polymer content in PMMA and is attributed to the phase separation between the conjugated polymers. Finally, the narrow band gap conjugated polymer, poly[bis(3,4-propylenedioxythiophene-dihexyl)]-cyanovinylene has been characterized for its electrochromic properties, illustrating the multifunctional nature of variable band gap conjugated polymers.

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