Organic Light Emitting Diodes - Innovative Light Sources

2019 ◽  
pp. 101-107
Author(s):  
Sergei A. Stakharny
Keyword(s):  
Light Source ◽  
Organic Light Emitting Diodes ◽  
Organic Leds ◽  
Light Sources ◽  
High Quality ◽  
Light Emitting ◽  
Organic Light ◽  
Lighting Systems ◽  
Physical Principles ◽  
Prospects Of Application

This article is a review of the new light source – organic LEDs having prospects of application in general and special lighting systems. The article describes physical principles of operation of organic LEDs, their advantages and principal differences from conventional non-organic LEDs and other light sources. Also the article devoted to contemporary achievements and prospects of development of this field in the spheres of both general and museum lighting as well as other spheres where properties of organic LEDs as high-quality light sources may be extremely useful.

scholarly journals Structural Analysis of Enhanced Performance Organic Light Emitting Diodes (OLEDs)

2020 ◽  
Vol 8 (9) ◽  
pp. 80-83
Keyword(s):  
High Efficiency ◽  
Structural Features ◽  
Comprehensive Analysis ◽  
Organic Light Emitting Diodes ◽  
Organic Leds ◽  
Light Sources ◽  
Light Emitting ◽  
Organic Light ◽  
Depth Analysis ◽  
Pi Bonds

We present a detailed study on structure of Organic LEDs (OLEDs) that promise flexibility and enhanced performance. Ordinary LEDs fail when it comes to need of ultra-smart size, thin, flexible smart screens and high efficiency light sources. With electroluminescent layer made of organic compounds, OLEDs promise all such features. We did a comprehensive analysis to find what structural features distinguish OLEDs from semiconductor LEDs. We found that it is the special six layered structure with organic emissive layer and delocalized charges due to weak pi bonds that enable OLEDs to perform better. We dis-cuss a few limitations related to production and life of these LEDs and suggest possible solutions to overcome these challenges. A rigorous, in-depth analysis of this structure is imperative to further comprehend the working of this device in order to make future devices cheaper and more efficient

Four color stacked white organic light-emitting diodes utilizing the concept of triplet harvesting

2011 ◽  
Vol 1286 ◽  
Author(s):  
Th. C. Rosenow ◽  
S. Olthof ◽  
S. Reineke ◽  
B. Lüssem ◽  
K. Leo
Keyword(s):  
Light Emitting Diodes ◽  
Blue Emission ◽  
Organic Light Emitting Diodes ◽  
Light Sources ◽  
Emission Layer ◽  
Light Emitting ◽  
Organic Light ◽  
Blue Emitters ◽  
Color Rendering ◽  
Triplet Harvesting

ABSTRACTOrganic light-emitting diodes (OLEDs) are developing into a competitive alternative to conventional light sources. Nevertheless, OLEDs need further improvement in terms of efficiency and color rendering for lighting applications. Fluorescent blue emitters allow deep blue emission and high stability, while phosphorescent blue emitter still suffer from insufficient stability. The concept of triplet harvesting is the key for achieving internal quantum efficiencies up to 100 % and simultaneously benefiting from the advantages of fluorescent blue emitters. Here, we present a stacked OLED consisting of two units comprising four different emitters in total. The first unit takes advantage of the concept of triplet harvesting and combines the light emission of a fluorescent blue and a phosphorescent red emitter. The second unit emits light from a single emission layer consisting of a matrix doped with phosphorescent green and yellow emitters. With this approach, we reach white color coordinates close to the standard illuminant A and a color rendering index of above 75. The presented devices are characterized by high luminous efficacies of above 30 lm/W on standard glass substrates without outcoupling enhancement.

scholarly journals Towards the Optimum Light Source Spectrum

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Andrew Chalmers ◽  
Snjezana Soltic
Keyword(s):  
Light Source ◽  
Large Scale ◽  
Source Spectrum ◽  
Light Sources ◽  
Luminous Efficacy ◽  
Light Emitting ◽  
Spectral Bands ◽  
Good Energy ◽  
Lighting Systems ◽  
Colour Rendering

This paper is concerned with designing light source spectra for optimum luminous efficacy and colour rendering. We demonstrate that it is possible to design light sources that can provide both good colour rendering and high luminous efficacy by combining the outputs of a number of narrowband spectral constituents. Also, the achievable results depend on the numbers and wavelengths of the different spectral bands utilized in the mixture. Practical realization of these concepts has been demonstrated in this pilot study which combines a number of simulations with tests using real LEDs (light emitting diodes). Such sources are capable of providing highly efficient lighting systems with good energy conservation potential. Further research is underway to investigate the practicalities of our proposals in relation to large-scale light source production.

High-quality all-fluorescent white organic light-emitting diodes obtained by balancing carriers with hole limit layer

2022 ◽  
Vol 123 ◽  
pp. 111917
Author(s):  
Kai Chen ◽  
Ruixia Wu ◽  
Xiaokang Li ◽  
Weiqiang Liu ◽  
Zhipeng Wei ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
High Quality ◽  
Light Emitting ◽  
Organic Light

A replacement for incandescent bulbs: high-efficiency blue-hazard free organic light-emitting diodes

2017 ◽  
Vol 5 (1) ◽  
pp. 176-182 ◽  
Author(s):  
J. H. Jou ◽  
H. H. Yu ◽  
F. C. Tung ◽  
C. H. Chiang ◽  
Z. K. He ◽  
...  
Keyword(s):  
Energy Saving ◽  
Light Source ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light

A blue-hazard free, healthy light source will become the mainstream of future lighting wherein higher energy saving is always a must.

scholarly journals Flexible organic light-emitting diodes for antimicrobial photodynamic therapy

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Cheng Lian ◽  
Marta Piksa ◽  
Kou Yoshida ◽  
Saydulla Persheyev ◽  
Krzysztof J. Pawlik ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Bacterial Infections ◽  
Light Emitting Diodes ◽  
High Irradiance ◽  
Organic Light Emitting Diodes ◽  
Light Sources ◽  
Driving Voltage ◽  
Light Emitting ◽  
Organic Light ◽  
Operational Lifetime

Abstract Bacterial infection and the growth of antibiotic resistance is a serious problem that leads to patient suffering, death and increased costs of healthcare. To address this problem, we propose using flexible organic light-emitting diodes (OLEDs) as light sources for photodynamic therapy (PDT) to kill bacteria. PDT involves the use of light and a photosensitizer to generate reactive oxygen species that kill neighbouring cells. We have developed flexible top-emitting OLEDs with the ability to tune the emission peak from 669 to 737 nm to match the photosensitizer, together with high irradiance, low driving voltage, long operational lifetime and adequate shelf-life. These features enable OLEDs to be the ideal candidate for ambulatory PDT light sources. A detailed study of OLED–PDT for killing Staphylococcus aureus was performed. The results show that our OLEDs in combination with the photosensitizer methylene blue, can kill more than 99% of bacteria. This indicates a huge potential for using OLEDs to treat bacterial infections.

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