High-efficiency ultrapure green organic light-emitting diodes

Fukagawa, Hirohiko; Oono, Taku; Iwasaki, Yukiko; Hatakeyama, Takuji; Shimizu, Takahisa

doi:10.1039/c7qm00588a

Cited by 67 publications

(51 citation statements)

References 27 publications

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“…Similar phenomenon was also observed in the previous report of narrowband green emitter PtN1N vs. PtOO3 [62]. Moreover, Fukagawa's work also demonstrated that the operational stability of PtN7N-based OLEDs could be comparable to that of the Ir(mppy) 3 -based ones, indicating the promise for the practical application of PtN7N by employing suitable host and charge-transporting materials [60,63].…”

Section: Other Types Of Tetradentate Platinum(ii) Complexessupporting

confidence: 85%

Section: Other Types Of Tetradentate Platinum(ii) Complexesmentioning

confidence: 99%

“…Very recently, Fukagawa and co-workers reported great progress in ultrapure green OLEDs based on a NHC emitter PtN7N [60], which was developed by Li′s group before 2014 [61]. The optimized OLED showed CIE coordinates of (0.18, 0.74) using a top-emitting OLED with a microcavity structure and also using a boron-based host material [60]. Fukagawa's work demonstrated that the narrowband emitter PtN7N was superior to the iridium(II)-based emitter Ir(mppy) 3 for the development of ultrapure green emitter to satisfy the BT.2020 for ultrahighdefinition displays [60], owing to the very small vibrational structures of PtN7N that could be well suppressed by microcavity technology.…”

Section: Other Types Of Tetradentate Platinum(ii) Complexesmentioning

confidence: 99%

“…The optimized OLED showed CIE coordinates of (0.18, 0.74) using a top-emitting OLED with a microcavity structure and also using a boron-based host material [60]. Fukagawa's work demonstrated that the narrowband emitter PtN7N was superior to the iridium(II)-based emitter Ir(mppy) 3 for the development of ultrapure green emitter to satisfy the BT.2020 for ultrahighdefinition displays [60], owing to the very small vibrational structures of PtN7N that could be well suppressed by microcavity technology. Similar phenomenon was also observed in the previous report of narrowband green emitter PtN1N vs. PtOO3 [62].…”

Section: Other Types Of Tetradentate Platinum(ii) Complexesmentioning

confidence: 99%

See 3 more Smart Citations

Tetradentate Cyclometalated Platinum(II) Complexes for Efficient and Stable Organic Light-Emitting Diodes

Li¹,

She²

2018

Light-Emitting Diode - An Outlook on the Empirical Features and Its Recent Technological Advancements

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As one of the most important phosphorescent emitters, tetradentate cyclometalated platinum(II) complexes have attracted much attention in recent years, because of the high luminescent efficiency, emission spectra, and color tuned easily, especially for the development of high-efficient deep-blue and "pure" blue emitters and single-doped white organic light-emitting diodes (OLEDs). Also, some platinum(II)-based OLEDs exhibited superior operational stability, indicating their potentials in full-color display and solidstate lighting applications. In this chapter, we will introduce the recent advances of the tetradentate cyclometalated platinum(II) complexes, including pyrazole, N-heterocyclic carbene, imidazole and pyridine-based complexes, molecular design, photophysical properties, and some of their device performances.From the spin statistics, it is well known that the singlet and triplet in the electrogenerated excitons are 25 and 75%, respectively [3]. As a result, OLEDs using fluorescent emitters, which emit from the singlet excited state, can achieve a peak internal quantum efficiency (IQE) only 25%. However, if heavy metal ion is incorporated into the organic ligand, phosphorescent emitters can break the spin-forbidden reactions, and fast intersystem crossing (IC) from singlet to triplet state can occur owing to the strong electron spin-orbit coupling (SOC); thus, heavy metal complexes have the potential to harvest both the electrogenerated singlet and triplet excitons and achieve 100% IQE. In 1998, Forrest and Thompson et al. and Che et al. first reported the electrogenerated phosphorescent platinum(II) [4] and osmium(II) [5] complexes, respectively. Afterward, more heavy metal complexes were found to be used as efficient phosphorescent materials, like iridium(III), ruthenium(II), palladium (II), rhodium (III), gold(III), and so on, and some reviews about these complexes have been published [6][7][8][9][10][11][12][13][14][15][16][17][18]. Among them, iridium(III) complexes have been most widely studied. Green and red phosphorescent iridium(III) emitters developed by Universal Display Corporation (UDC) have been successfully commercialized due to their superior efficiency and long operational lifetime. OLED display doped these emitters that have been adopted for several types of high-end personal electronics, such as Samsung Galaxy, LG OLED television, Apple smart watch, and iPhone X. Compared with the liquid crystal display (LCD), OLED display have many outstanding merits, such as low-cost fabrication methods, high color quality, and high-luminance efficiency and also many advantages of low power consumption, wide-viewing angle, wide temperature range, fast response, etc [19,20]. Thus, OLED has been widely considered as the next generation of full-color display and solidstate lighting technologies.The development of high efficient and stable phosphorescent emitters is of the most importance for the development of OLEDs and their application. Although thousands of phosphorescent heavy metal complexes have ...

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Section: Other Types Of Tetradentate Platinum(ii) Complexessupporting

confidence: 85%

Section: Other Types Of Tetradentate Platinum(ii) Complexesmentioning

confidence: 99%

Section: Other Types Of Tetradentate Platinum(ii) Complexesmentioning

confidence: 99%

Section: Other Types Of Tetradentate Platinum(ii) Complexesmentioning

confidence: 99%

See 2 more Smart Citations

Tetradentate Cyclometalated Platinum(II) Complexes for Efficient and Stable Organic Light-Emitting Diodes

Li¹,

She²

2018

Light-Emitting Diode - An Outlook on the Empirical Features and Its Recent Technological Advancements

View full text Add to dashboard Cite

show abstract

“…[ 6 ] The broad emission band creates a restriction for TADF materials to satisfy the requirement of high color purity displays based on R/G/B (red/green/blue) emitters. [ 7 ] Although the color purity of original broad electroluminescence (EL) band can be modified by introducing a color filter and/or an optical microcavity in commercial OLED displays, the modification leads to significant increase in cost and power consumption. [ 8–10 ] Thus, the development of efficient narrowband emissive materials, especially those able to achieve high color purity that comply with the Commission Internationale de L'Eclairage (CIE) coordinates requirements defined by the broadcasting standards, is highly important.…”

Section: Figurementioning

confidence: 99%

Molecular‐Structure and Device‐Configuration Optimizations toward Highly Efficient Green Electroluminescence with Narrowband Emission and High Color Purity

Cheng

et al. 2020

Advanced Optical Materials

321

164

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Thermally activated delayed fluorescence (TADF) materials that are able to realize electroluminescence showing simultaneously narrow emission band, high color purity, and high efficiency are highly demanded for display applications. Up to now, a few blue emissive TADF materials with such characteristics have been reported, while green TADF materials with such features are extremely scarce. Herein, two TADF compounds with highly efficient narrowband bluish green/green emission (full‐width at half‐maximum (FWHM): 22 and 21 nm in toluene) induced by multiple resonance effect are reported. An optimized organic light‐emitting diode based on the green emissive compound shows a fairly narrow electroluminescent spectrum (FWHM: 33 nm), as well as an excellent color purity with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.20, 0.65), which is a close resemblance to the standard green‐light CIE coordinates of (0.21, 0.71) defined by the National Television System Committee. Meanwhile, the maximum external quantum efficiency (EQE) up to 25.5% is achieved and a high EQE of 20.1% is maintained at a practical high luminance of 1000 cd m−2. The outstanding device performance of the compound makes it attractive for potential practical applications.

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Dual‐Microcavity Technology for Red, Green, and Blue Electroluminescent Devices

Kim,

Lee,

Cho

et al. 2023

Adv Funct Materials

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Microcavity structures are used in inorganic‐, organic‐, quantum‐dot‐, and perovskite‐based electroluminescent (EL) devices to advance next‐generation displays. However, there are difficulties in controlling electrical characteristics and patterning processes for producing different thicknesses for each red, green, and blue (RGB) subpixel, and the issues are more challenging in the high‐resolution display for future realistic media. Here, a novel design method is presented for a dual‐microcavity structure that controls high‐order modes of a second cavity stacked on top of EL devices with the same cavity length for each subpixel to produce multiple peaks at RGB resonant wavelengths. The dual‐microcavity effect demonstrated by top‐emitting organic light‐emitting diodes (OLEDs) can be conveniently fabricated via in situ deposition. By modulating the high‐order modes, the spectral characteristics of each RGB dual‐microcavity top‐emitting OLED (DMTOLED) are manipulated while its electrical properties are maintained. Green DMTOLED exhibits a maximum luminance of 2.075 × 105 cd m−2, allowing applications not only for commercialized displays but also for outdoor augmented reality and automotive displays. Furthermore, dual‐microcavity structures with narrow spectral bandwidths can be applied to next‐generation EL devices for more realistic media. The method is expected to be applied industrially, promoting the advancement of EL devices for next‐generation displays.

show abstract

High-efficiency ultrapure green organic light-emitting diodes

Abstract: Efficient ultrapure green OLEDs were demonstrated by using a platinum complex (PtN7N) and a top emitting structure.

Cited by 67 publications

References 27 publications

Tetradentate Cyclometalated Platinum(II) Complexes for Efficient and Stable Organic Light-Emitting Diodes

Tetradentate Cyclometalated Platinum(II) Complexes for Efficient and Stable Organic Light-Emitting Diodes

Molecular‐Structure and Device‐Configuration Optimizations toward Highly Efficient Green Electroluminescence with Narrowband Emission and High Color Purity

Dual‐Microcavity Technology for Red, Green, and Blue Electroluminescent Devices

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