Synthesis and electroluminescence properties of new blue dual-core OLED emitters using bulky side chromophores

Lee, Suji; Kim, Beomjin; Jung, Hyocheol; Shin, Hoon−Kyu; Lee, Hayoon; Lee, Jae-Hyun; Park, Jong‐Wook

doi:10.1016/j.dyepig.2016.08.010

Cited by 22 publications

(13 citation statements)

References 24 publications

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“…For the last 20 years, reaching stable and highly efficient blue PhOLEDs has been an intense research field worldwide . To date, all the high‐efficiency blue PhOLEDs (with external quantum efficiency (EQE) > 20%) are multilayer devices, which are constituted of a stack of organic layers in order to improve the injection, transport and recombination of charges within the EML. There are usually in a PhOLED stack, a hole‐transporting layer (HTL), an electron‐transporting layer (ETL), a hole‐blocking layer (HBL), and an electron‐blocking layer (EBL) and these layers can even be doubled.…”

Section: Introductionmentioning

confidence: 99%

Spirophenylacridine‐2,7‐(diphenylphosphineoxide)‐fluorene: A Bipolar Host for High‐Efficiency Single‐Layer Blue Phosphorescent Organic Light‐Emitting Diodes

Lucas

Ibraikulov

Quinton

et al. 2019

Advanced Optical Materials

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Herein, a high‐efficiency host material for single‐layer phosphorescent organic light‐emitting diodes (SL‐PhOLEDs) is reported. This host material is synthesized via an efficient approach and is constructed on the association of an electron‐rich phenylacridine unit connected by a spiro carbon atom to an electron‐deficient 2,7‐bis(diphenylphosphineoxide)‐fluorene. In addition to a high ET value and adequate highest occupied molecular orbital/lowest unoccupied molecular orbital energy levels, the key point in this molecular design is the suitable balance between hole and electron mobilities, which leads to a high‐performance blue SL‐PhOLED with an external quantum efficiency of 17.6% (current efficiency = 37.8 cd A−1 and power efficiency = 37.1 lm W−1) and a low Von of 2.5 V. This performance shows that the molecular design of the present host fulfills the criteria required for high‐efficiency SL‐PhOLEDs. The present performance is one of the highest reported to date for blue SL‐PhOLEDs and more importantly shows the potential of such a molecular design to reach very high‐performance single‐layer devices.

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Section: Introductionmentioning

confidence: 99%

Spirophenylacridine‐2,7‐(diphenylphosphineoxide)‐fluorene: A Bipolar Host for High‐Efficiency Single‐Layer Blue Phosphorescent Organic Light‐Emitting Diodes

Lucas

Ibraikulov

Quinton

et al. 2019

Advanced Optical Materials

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“…For the last thirty years of research in material science, spirobifluorene-based compounds have been extensively studied for applicationsi no rganic electronicsa nd especially in organic light-emitting diodes (OLED). [1][2][3] The incorporation of spiro linkagesi ns mall molecular units is nowadays ap owerful molecular technique to design efficient and stable organic semiconductors:f luorophores for OLEDs, [3][4][5][6][7][8] high-triplet host materials forp hosphorescent OLEDs, [2,[9][10][11][12] thermally activated delayed fluorescenceh osts, [13][14][15] and electron-donor [16][17][18] or nonfullerenea cceptors [19][20][21][22] for solar cells. The spirobifluorenef ragment combines the physical advantages of an orthogonal spiro configuration (high thermala nd morphological stability) and the appealing properties of the fluorene unit (e.g.…”

Section: Introductionmentioning

confidence: 99%

Cyclization of Terphenyl‐Bisfluorenols: A Mechanistic Study of the Regioselectvity

Poriel

Barrière

Rault‐Berthelot

et al. 2019

Chemistry A European J

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The mechanism of the bicyclization reaction of a series of terphenyl‐bisfluorenols into dispiro[fluorene‐9,6′‐indeno[1,2‐b]fluorene‐12′,9′′‐fluorene] and dispiro[fluorene‐9,6′‐indeno[2,1‐a]fluorene‐12′,9′′‐fluorene] is reported. Through a combined experimental and theoretical study, the different parameters that drive the regioselectivity of this cyclization reaction have been studied and are presented.

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“…Most current research involving blue emitters deal with classical scaffolds with known good fluorescence yields such as anthracene, pyrene, and fluorene. However, the possibility of excimer formation through packing usually leads to reduced electroluminescence efficiency and degradation of color purity in such devices . In that context, the color tuning of four‐coordinate organoboron compounds achieved by modifying ligands provides an alternative for the development of new blue emitters , .…”

Section: Introductionmentioning

confidence: 99%

New Boron(III) Blue Emitters for All‐Solution Processed OLEDs: Molecular Design Assisted by Theoretical Modeling

et al. 2019

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Luminescent boron(III) complexes have recently been employed as emitters in organic light‐emitting diodes (OLEDs) with reasonable success. They are easy to prepare and sufficiently stable to be used in such devices, being of great interest as a simple molecular emissive layer. Although emitters for this class with all colors have already been reported, highly efficient and stable blue emitters for applications in solution processed devices still pose a challenge. Here, we report the design, synthesis, and characterization of new boron complexes based on the 2‐(benzothiazol‐2‐yl)phenol ligand (HBT), with different donor and acceptor groups responsible for modulating the emission properties, from blue to red. The molecular design was assisted by calculations using our newly developed formalism, where we demonstrate that the absorption and fluorescence spectra can be successfully predicted, which is a powerful technique to evaluate molecular photophysical properties prior to synthesis. In addition, density functional theory (DFT) enables us to understand the molecular and electronic structure of the molecules in greater detail. The molecules studied here presented fluorescence efficiencies as high as Φ = 0.88 and all solution processed OLEDs were prepared and characterized under an ambient atmosphere, after dispersion in the emitting layer. Surprisingly, even considering these rather simple experimental conditions, the blue emitters displayed superior properties compared to those in the present literature, in particular with respect to the stability of the current efficiency.

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Synthesis and electroluminescence properties of new blue dual-core OLED emitters using bulky side chromophores

Cited by 22 publications

References 24 publications

Spirophenylacridine‐2,7‐(diphenylphosphineoxide)‐fluorene: A Bipolar Host for High‐Efficiency Single‐Layer Blue Phosphorescent Organic Light‐Emitting Diodes

Spirophenylacridine‐2,7‐(diphenylphosphineoxide)‐fluorene: A Bipolar Host for High‐Efficiency Single‐Layer Blue Phosphorescent Organic Light‐Emitting Diodes

Cyclization of Terphenyl‐Bisfluorenols: A Mechanistic Study of the Regioselectvity

New Boron(III) Blue Emitters for All‐Solution Processed OLEDs: Molecular Design Assisted by Theoretical Modeling

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