A polymer light-emitting diode as an optical communication light source

Barlow, Iain; Kreouzis, Theo; Lidzey, David G.

doi:10.1016/j.orgel.2007.04.003

Cited by 8 publications

(6 citation statements)

References 14 publications

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“…This effect has previously been quantified by Barlow et al for equivalent OLEDs with a range of pixel areas. [34] In their work, it was demonstrated that the apparent area dependence of current density results from the fact that in larger area OLEDs, proportionally more voltage is dissipated over the electrode area (as distance from the electrical contact is increased), with relatively less voltage then being dropped across the polymer layer. This effect is strongly influenced by electrode sheet resistance and device geometry.…”

Section: The Electromodulation Response Of Pristine F8t2 Pledsmentioning

confidence: 99%

Organic Light‐Emitting Diodes Based on Poly(9,9‐dioctylfluorene‐co‐bithiophene) (F8T2)

Levermore

Jin

Wang

et al. 2009

Adv Funct Materials

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A study of the optical properties of poly(9,9‐dioctylfluorene‐co‐bithiophene) (F8T2) is reported, identifying this polymer as one that possesses a desirable combination of charge transport and light emission properties. The optical and morphological properties of a series of polymer blends with F8T2 dispersed in poly(9,9‐dioctylfluorene) (PFO) are described and almost pure‐green emission from light emitting diodes (LEDs) based thereon is demonstrated. High luminance green electroluminescence from LEDs using only a thin film of F8T2 for emission is also reported. The latter demonstration for a polymer previously primarily of interest for effective charge transport constitutes an important step in the development of emissive materials for applications where a union of efficient light emission and effective charge transport is required.

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Section: The Electromodulation Response Of Pristine F8t2 Pledsmentioning

confidence: 99%

Organic Light‐Emitting Diodes Based on Poly(9,9‐dioctylfluorene‐co‐bithiophene) (F8T2)

Levermore

Jin

Wang

et al. 2009

Adv Funct Materials

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“…The response speed of LEDs is limited by the time delay from the receiving of an electrical signal to the generation of photons induced by carrier recombination (Box 2). Following the development and success of OLEDs for display applications, part of the research focus has switched to the field of adopting OLEDs as transmitters for optical communications in the past decade [27][28][29][30][31][32][33][34] . During the development of OLEDs, various fluorescent and phosphorescent emitters have been found to provide highly efficient devices.…”

Section: Boosting the Frequency Responsementioning

confidence: 99%

“…45 Ref. 27 ]diethylamine (ODEA) used to passivate organic cations of perovskites. G3 is the third-generation OLEDs fabricated in ref.…”

Section: Enhancing the Eqe Towards Practical Applicationsmentioning

confidence: 99%

Emerging light-emitting diodes for next-generation data communications

et al. 2021

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emiconductor lasers have typically been used to tackle speed and capacity bottlenecks in data communications 1 . However, due to the relatively high manufacturing costs and the relatively complex driver circuits of lasers 2 , as well as eye safety issues, alternative solutions have been sought for future applications in human-centric systems, short-distance communications and indoor wireless data services. Light-emitting diodes (LEDs) are a cost-effective and low-power alternative 2-4 . LED-based links are, in particular, expected to be extensively used in Internet of Things (IoT) and 6G technologies, and in moderate/high-speed photonic interconnects, visible light communications (VLC), underwater communications and accurate indoor positioning applications [2][3][4][5] .The potential use of LEDs in next-generation data communications is driven by the rapid development of energy-efficient LEDs that can function as illumination and signalling devices. The concepts and fundamental principles of LED links are illustrated in Box 1. Micro-LEDs (µLEDs) based on crystalline inorganic III-V semiconductors have been widely examined for communications 2 . Because of advances in epitaxy, lithography and flip-chip techniques 6 , III-V µLEDs have delivered a modulation bandwidth from several hundred megahertz to over one gigahertz 2,7 . A non-polar m-plane InGaN/GaN µLED with a high modulation bandwidth of 1.5 GHz was demonstrated in 2018 7 , and a 1.3 GHz electrical-to-optical bandwidth quantum dot (QD) µLED was recently reported with a data rate of 4 Gbps (ref. 8 ). Nevertheless, conventional approaches are challenged by the high requirements for low size, weight, power and cost of next-generation data communication systems 5,9,10 .Organic semiconductors, colloidal quantum dots (CQDs) and metal halide perovskites offer tailorable optoelectronic properties, mechanical flexibility and low-cost processing 10 . These characteristics make them attractive candidates for use in low-cost and low-power LED links in next-generation integrated and scalable data communication modules. Thus, while conventional inorganic thin-film technologies are likely to continue to play a dominant role in optical communications 9,11 , we believe that LEDs based on these emerging materials can provide a complementary role. In this Review, we examine the development of emerging semiconductor materials for LEDs and colour converters. We first consider the fundamentals of LED-based optical communication systems, and then explore efforts to boost the frequency response and enhance the external quantum efficiency (EQE) of LEDs based on emerging materials. Finally, we consider the challenges that exist in developing these LEDs for practical communication systems.

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“…Increasing demand for wireless communications has driven research into improving data transmission concepts [11][12][13][14][15][16][17][18][19][20][21] . The oligofluorene arms have a substituent effect on the BODIPY core and therefore the increase in the number of arms influences the photophysics of the material.…”

Section: Institute Of Physical-organic Chemistry and Coal Chemistry mentioning

confidence: 99%

BODIPY star-shaped molecules as solid state colour converters for visible light communications

Vithanage

Manousiadis

Sajjad

et al. 2016

Applied Physics Letters

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Copyright © and Moral Rights are retained by the author(s) and/ or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This item cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder(s). The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders.This document is the author's post-print version, incorporating any revisions agreed during the peer-review process. Some differences between the published version and this version CURVE is the Institutional Repository for Coventry University may remain and you are advised to consult the published version if you wish to cite from it. They are broadband visible emitters whose emission can be tuned by changing the chemical structure, and can have high photoluminescent quantum yields (PLQY) of up to 90% in undiluted films 5,9,10 . This combined with simple and low cost solution processing techniques make them attractive materials for optoelectronic devices.An emerging application area for organic semiconductors is in the field of visible light communications (VLC).Increasing demand for wireless communications has driven research into improving data transmission concepts 3The oligofluorene arms have a substituent effect on the BODIPY core and therefore the increase in the number of arms influences the photophysics of the material.Solid state colour converters were spin-coated from solution to make thin films on quartz substrates for the photophysical studies. Films of thickness ca. 100 nm were deposited from solutions at concentrations of 10 and 20 mg/ml for photophysical and communications measurements respectively. These were spin-coated at 1500 rpm for 60 seconds. Figure 1 (bottom) shows the absorption and PL spectra of the films for each molecule. The absorption spectra show peaks at 450 and 620 nm for Y1; 350, 473 and 626 nm for Y2; 350, 477 and 625nm for Y3; and 366, 480 and 625nm for Y4. The absorption band below 400 nm is attributed to the fluorene arms and increases in intensity with arm length. Y1 has a peak in absorption at 450 nm matching well the emission of the blue LEDs used for lighting, and this feature shifts slightly to longer wavelengths for longer arms as seen in Figure 1. The peak emission wavelengths were in the red region of the spectrum, 663, 679, 682, 682 nm for Y1, Y2, Y3and Y4 respectively. The red PL emission comes from an extended conjugation across the BODIPY core and adjacent fluorene units as has been described previously 24 . The bathochromic shift from Y1 to Y2 is also evident in solution 23,24 and indicates that there is a further delocalisation of the excited state across the BODIPY and neighbouring fluorene units.Time-resolved fluorescence measurements were conducted using the time correlated single photon counting (TCSPC) technique, exciting the materials at 375 nm and detecting at the corresponding peak PL...

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A polymer light-emitting diode as an optical communication light source

Cited by 8 publications

References 14 publications

Organic Light‐Emitting Diodes Based on Poly(9,9‐dioctylfluorene‐co‐bithiophene) (F8T2)

Organic Light‐Emitting Diodes Based on Poly(9,9‐dioctylfluorene‐co‐bithiophene) (F8T2)

Emerging light-emitting diodes for next-generation data communications

BODIPY star-shaped molecules as solid state colour converters for visible light communications

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