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Highly Efficient Candlelight Organic Light-Emitting Diode with a Very Low Color Temperature. Molecules 2021; 26:molecules26247558. [PMID: 34946643 PMCID: PMC8707034 DOI: 10.3390/molecules26247558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/04/2021] [Accepted: 12/07/2021] [Indexed: 11/16/2022] Open
Abstract
Low color temperature candlelight organic light-emitting diodes (LEDs) are human and environmentally friendly because of the absence of blue emission that might suppress at night the secretion of melatonin and damage retina upon long exposure. Herein, we demonstrated a lighting device incorporating a phenoxazine-based host material, 3,3-bis(phenoxazin-10-ylmethyl)oxetane (BPMO), with the use of orange-red and yellow phosphorescent dyes to mimic candlelight. The resultant BPMO-based simple structured candlelight organic LED device permitted a maximum exposure limit of 57,700 s, much longer than did a candle (2750 s) or an incandescent bulb (1100 s) at 100 lx. The resulting device showed a color temperature of 1690 K, which is significantly much lower than that of oil lamps (1800 K), candles (1900 K), or incandescent bulbs (2500 K). The device showed a melatonin suppression sensitivity of 1.33%, upon exposure for 1.5 h at night, which is 66% and 88% less than the candle and incandescent bulb, respectively. Its maximum power efficacy is 23.1 lm/W, current efficacy 22.4 cd/A, and external quantum efficiency 10.2%, all much higher than the CBP-based devices. These results encourage a scalable synthesis of novel host materials to design and manufacture high-efficiency candlelight organic LEDs.
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Pyridinyl-Carbazole Fragments Containing Host Materials for Efficient Green and Blue Phosphorescent OLEDs. Molecules 2021; 26:molecules26154615. [PMID: 34361768 PMCID: PMC8348521 DOI: 10.3390/molecules26154615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 11/29/2022] Open
Abstract
Pyridinyl-carbazole fragments containing low molar mass compounds as host derivatives H1 and H2 were synthesized, investigated, and used for the preparation of electro-phosphorescent organic light-emitting devices (PhOLEDs). The materials demonstrated high stability against thermal decomposition with the decomposition temperatures of 361–386 °C and were suitable for the preparation of thin amorphous and homogeneous layers with very high values of glass transition temperatures of 127–139 °C. It was determined that triplet energy values of the derivatives are, correspondingly, 2.82 eV for the derivative H1 and 2.81 eV for the host H2. The new derivatives were tested as hosts of emitting layers in blue, as well as in green phosphorescent OLEDs. The blue device with 15 wt.% of the iridium(III)[bis(4,6-difluorophenyl)-pyridinato-N,C2′]picolinate (FIrpic) emitter doping ratio in host material H2 exhibited the best overall characteristics with a power efficiency of 24.9 lm/W, a current efficiency of 23.9 cd/A, and high value of 10.3% of external quantum efficiency at 100 cd/m2. The most efficient green PhOLED with 10 wt% of Ir(ppy)3 {tris(2-phenylpyridine)iridium(III)} in the H2 host showed a power efficiency of 34.1 lm/W, current efficiency of 33.9 cd/A, and a high value of 9.4% for external quantum efficiency at a high brightness of 1000 cd/m2, which is required for lighting applications. These characteristics were obtained in non-optimized PhOLEDs under an ordinary laboratory atmosphere and could be improved in the optimization process. The results demonstrate that some of the new host materials are very promising components for the development of efficient phosphorescent devices.
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Beucher H, Kumar S, Kumar R, Merino E, Hu WH, Stemmler G, Cuesta-Galisteo S, González JA, Bezinge L, Jagielski J, Shih CJ, Nevado C. Phosphorescent κ 3 -(N^C^C)-Gold(III) Complexes: Synthesis, Photophysics, Computational Studies and Application to Solution-Processable OLEDs. Chemistry 2020; 26:17604-17612. [PMID: 32780903 DOI: 10.1002/chem.202003571] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Indexed: 12/19/2022]
Abstract
Efficient OLED devices have been fabricated using organometallic complexes of platinum group metals. Still, the high material cost and low stability represent central challenges for their application in commercial display technologies. Based on its innate stability, gold(III) complexes are emerging as promising candidates for high-performance OLEDs. Here, a series of alkynyl-, N-heterocyclic carbene (NHC)- and aryl-gold(III) complexes stabilized by a κ3 -(N^C^C) template have been prepared and their photophysical properties have been characterized in detail. These compounds exhibit good photoluminescence quantum efficiency (ηPL ) of up to 33 %. The PL emission can be tuned from sky-blue to yellowish green colors by variations on both the ancillary ligands as well as on the pincer template. Further, solution-processable OLED devices based on some of these complexes display remarkable emissive properties (ηCE 46.6 cd.A-1 and ηext 14.0 %), thus showcasing the potential of these motifs for the low-cost fabrication of display and illumination technologies.
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Affiliation(s)
- Hélène Beucher
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Sudhir Kumar
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Roopender Kumar
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Estíbaliz Merino
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Wei-Hsu Hu
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Gerrit Stemmler
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Sergio Cuesta-Galisteo
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Jorge A González
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Léonard Bezinge
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Jakub Jagielski
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Chih-Jen Shih
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH-Zürich, 8093, Zürich, Switzerland
| | - Cristina Nevado
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
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Jou JH, Lo D, Su YT, Dubey DK, Kuan DH, Chiang CH, Masim FCP, Hatanaka K, Liu B, Subiyanto I, Liu KC, Nagar MR. Surface plasmon-enhanced solution-processed phosphorescent organic light-emitting diodes by incorporating gold nanoparticles. NANOTECHNOLOGY 2020; 31:295204. [PMID: 32050168 DOI: 10.1088/1361-6528/ab7588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Organic light-emitting diodes (OLEDs) have attracted increasing attention due to their superiority as high quality displays and energy-saving lighting. However, improving the efficiency of solution-processed devices especially based on blue emitter remains a challenge. Excitation of surface plasmons on metallic nanoparticles has potential for increasing the absorption and emission from optoelectronic devices. We demonstrate here that the incorporation of gold nano particles (GNPs) in the hole injection layer of poly(3,4-ethylene dioxythiophene):polystyrene sulfonic acid with an appropriate size and doping concentration can greatly enhance the efficiency OLED device especially at higher voltage. Apparently, the spectral of the multiple plasmon resonances of the GNPs and the luminescence of the emitting materials significantly overlap with each other. At 1000 cd m-2 for example, the power efficiency of a studied green device is increased from 29.0 to 36.2 lm W-1, an increment of 24.8%, and the maximum brightness improved from 21 550 to 27 810 cd m-2, an increment of 29.1%, as 2 wt% of a 12 nm GNP is incorporated. Remarkably, designed blue OLED also exhibited an increment of 50% and 35% in power efficacy at 100 and 1000 cd m-2, respectively, for same device structure. The reason why the enhancement is marked may be attributed to a strong absorption of the short-wavelength emission from the device by the gold nano particles, which in turn initiates a strong surface plasmon resonance effect, leading to a high device efficiency.
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Affiliation(s)
- Jwo-Huei Jou
- Department of Materials Science and Engineering, National Tsing Hua University, 300, Taiwan
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Benjamin H, Fox MA, Batsanov AS, Al-Attar HA, Li C, Ren Z, Monkman AP, Bryce MR. Pyridylpyrazole N^N ligands combined with sulfonyl-functionalised cyclometalating ligands for blue-emitting iridium(iii) complexes and solution-processable PhOLEDs. Dalton Trans 2017; 46:10996-11007. [DOI: 10.1039/c7dt02289a] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A blue phosphorescent emitter for PhOLEDs with brightness of 5400 cd m−2 at 10 V and λELmax 460 nm, CIEx,y (0.15, 0.21).
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Affiliation(s)
- Helen Benjamin
- Department of Chemistry
- Durham University
- Durham DH1 3LE
- UK
| | - Mark A. Fox
- Department of Chemistry
- Durham University
- Durham DH1 3LE
- UK
| | | | | | - Chensen Li
- State Key Laboratory of Chemical Resource Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- China
| | - Zhongjie Ren
- State Key Laboratory of Chemical Resource Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- China
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Benjamin H, Zheng Y, Batsanov AS, Fox MA, Al-Attar HA, Monkman AP, Bryce MR. Sulfonyl-Substituted Heteroleptic Cyclometalated Iridium(III) Complexes as Blue Emitters for Solution-Processable Phosphorescent Organic Light-Emitting Diodes. Inorg Chem 2016; 55:8612-27. [DOI: 10.1021/acs.inorgchem.6b01179] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Helen Benjamin
- Department of Chemistry and ‡Department of
Physics, Durham University, Durham DH1 3LE, U.K
| | - Yonghao Zheng
- Department of Chemistry and ‡Department of
Physics, Durham University, Durham DH1 3LE, U.K
| | - Andrei S. Batsanov
- Department of Chemistry and ‡Department of
Physics, Durham University, Durham DH1 3LE, U.K
| | - Mark A. Fox
- Department of Chemistry and ‡Department of
Physics, Durham University, Durham DH1 3LE, U.K
| | - Hameed A. Al-Attar
- Department of Chemistry and ‡Department of
Physics, Durham University, Durham DH1 3LE, U.K
| | - Andrew P. Monkman
- Department of Chemistry and ‡Department of
Physics, Durham University, Durham DH1 3LE, U.K
| | - Martin R. Bryce
- Department of Chemistry and ‡Department of
Physics, Durham University, Durham DH1 3LE, U.K
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Keawin T, Sooksai C, Prachumrak N, Kaewpuang T, Muenmart D, Namuangruk S, Jungsuttiwong S, Sudyoadsuk T, Promarak V. Oligoarylenes end-capped with carbazol-N-yl-carbazole as color tunable light-emitting and hole-transporting materials for solution-processed OLEDs. RSC Adv 2015. [DOI: 10.1039/c4ra16458j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
A series of oligoarylenes (CAr) exhibited blue to red fluorescence with hole-transporting properties. Simple structured solution-processed CAr-based OLEDs emitted stable colors spanning the visible spectrum and white light with luminance efficiencies up to 13.73 cd A−1.
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Affiliation(s)
- T. Keawin
- Department of Chemistry
- Faculty of Science
- Ubon Ratchathani University
- Ubon Ratchathani 34190
- Thailand
| | - C. Sooksai
- Department of Chemistry
- Faculty of Science
- Ubon Ratchathani University
- Ubon Ratchathani 34190
- Thailand
| | - N. Prachumrak
- School of Chemistry
- Institute of Science
- Suranaree University of Technology
- Nakhon Ratchasima 30000
- Thailand
| | - T. Kaewpuang
- School of Chemistry
- Institute of Science
- Suranaree University of Technology
- Nakhon Ratchasima 30000
- Thailand
| | - D. Muenmart
- School of Chemistry
- Institute of Science
- Suranaree University of Technology
- Nakhon Ratchasima 30000
- Thailand
| | - S. Namuangruk
- National Nanotechnology Center
- Pathumthani 12120
- Thailand
| | - S. Jungsuttiwong
- Department of Chemistry
- Faculty of Science
- Ubon Ratchathani University
- Ubon Ratchathani 34190
- Thailand
| | - T. Sudyoadsuk
- Department of Chemistry
- Faculty of Science
- Ubon Ratchathani University
- Ubon Ratchathani 34190
- Thailand
| | - V. Promarak
- School of Chemistry
- Institute of Science
- Suranaree University of Technology
- Nakhon Ratchasima 30000
- Thailand
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Tavasli M, Moore TN, Zheng Y, Bryce MR, Fox MA, Griffiths GC, Jankus V, Al-Attar HA, Monkman AP. Colour tuning from green to red by substituent effects in phosphorescent tris-cyclometalated iridium(iii) complexes of carbazole-based ligands: synthetic, photophysical, computational and high efficiency OLED studies. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm15049b] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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M'hamedi A, Batsanov AS, Fox MA, Bryce MR, Abdullah K, Al-Attar HA, Monkman AP. Dinuclear iridium(iii) complexes of cyclometalated fluorenylpyridine ligands as phosphorescent dopants for efficient solution-processed OLEDs. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm31143g] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Kim S, Hong K, Kim K, Lee I, Lee JL. Phase-controllable copper oxides for an efficient anode interfacial layer in organic light-emitting diodes. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c1jm14218f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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