The Experts below are selected from a list of 33705 Experts worldwide ranked by ideXlab platform
Junji Kido - One of the best experts on this subject based on the ideXlab platform.
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low driving voltage blue phosphorescent organic light Emitting Devices with external quantum efficiency of 30
Advanced Materials, 2014Co-Authors: Kazuo Udagawa, Hisahiro Sasabe, Cao Cai, Junji KidoAbstract:A homoleptic iridium (iii) tris(pheny-limidazolinate) complex realizes a high EQE of 30%, a low turn-on voltage of 2.5 V, and a small efficiency roll-off in a blue organic light-Emitting Device (OLED). This Device also shows high power efficiencies over 75 lm W(-1) and an ideal light distribution pattern at 100 cd m(-2).
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Development of high performance OLEDs for general lighting
Journal of Materials Chemistry C, 2013Co-Authors: Hisahiro Sasabe, Junji KidoAbstract:Since the development of the first white organic light-Emitting Device (OLED) in 1993, twenty years have passed. The power efficiency and lifetime of this white OLED were reportedly only
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optimizing the charge balance of fluorescent organic light Emitting Devices to achieve high external quantum efficiency beyond the conventional upper limit
Advanced Materials, 2012Co-Authors: Go Nakata, Hisahiro Sasabe, Fumiya Satoh, Daisuke Yokoyama, Junji KidoAbstract:The external quantum efficiencies (EQEs) of fluorescent light Emitting Devices are drastically improved by optimizing the charge balance. When N,N'-di(naphthalene-1-yl)- N,N'-diphenylbenzidine (NPD) is used as a hole-transporting layer (HTL) and Alq(3) as an electron-transporting layer (ETL) with the green dopant 2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-10-(2-benzothiazolyl)quinolizino-[9,9a,1gh]coumarin (C545T), the EQE is observed to be approximately 3%. However, when the HTL and ETL materials are optimized, a 7.5% external quantum efficiency (EQE) in a green-Emitting Device and an 8.2% EQE in a blue-Emitting Device are achieved at 100 cd m(-2) .
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Optimizing the Charge Balance of Fluorescent Organic Light‐Emitting Devices to Achieve High External Quantum Efficiency Beyond the Conventional Upper Limit
Advanced materials (Deerfield Beach Fla.), 2012Co-Authors: Go Nakata, Hisahiro Sasabe, Fumiya Satoh, Daisuke Yokoyama, Junji KidoAbstract:The external quantum efficiencies (EQEs) of fluorescent light Emitting Devices are drastically improved by optimizing the charge balance. When N,N'-di(naphthalene-1-yl)- N,N'-diphenylbenzidine (NPD) is used as a hole-transporting layer (HTL) and Alq(3) as an electron-transporting layer (ETL) with the green dopant 2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-10-(2-benzothiazolyl)quinolizino-[9,9a,1gh]coumarin (C545T), the EQE is observed to be approximately 3%. However, when the HTL and ETL materials are optimized, a 7.5% external quantum efficiency (EQE) in a green-Emitting Device and an 8.2% EQE in a blue-Emitting Device are achieved at 100 cd m(-2) .
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wide energy gap electron transport materials containing 3 5 dipyridylphenyl moieties for an ultra high efficiency blue organic light Emitting Device
Chemistry of Materials, 2008Co-Authors: Hisahiro Sasabe, Eisuke Gonmori, Takayuki Chiba, Daisaku Tanaka, Takashi Takeda, Kenichi Nakayama, Junji KidoAbstract:An ultra high efficiency blue organic light-Emitting Device using wide-energy-gap electron-transport material containing 3,5-dipyridylphenyl moieties and blue phosphorescent emitter, FIrpic, was developed. The optimized Device showed extremely high power efficiencies of 56 lm/W (53 cd/A) at 100 cd/m2 and 42 lm/W (46 cd/A) at 1000 cd/m2 without light outcoupling enhancement.
Kazumi Matsushige - One of the best experts on this subject based on the ideXlab platform.
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enhanced performance of organic light Emitting Device by insertion of conducting insulating wo3 anodic buffer layer
Synthetic Metals, 2005Co-Authors: Jingze Li, Masayuki Yahiro, Kenji Ishida, Hirofumi Yamada, Kazumi MatsushigeAbstract:Abstract Tungsten oxide (WO3) ultrathin film with high optical transparency is deposited on indium–tin oxide glass as hole injection layer of organic light Emitting Device (OLED). As-deposited WO3 film is amorphous and insulating, wherein the buffer thickness of 0.5 nm shows enhancement of hole injection in OLED. The Device performance is further enhanced after the as-deposited WO3 film is thermally treated, which is ascribed to lowering of the effective energy barrier height for hole injection. The annealed buffer layer is identified to be a semiconductor with crystalline structure. Although the thickness of the annealed WO3 buffer layer is up to 1.5 nm, the Device performance is still better than that of unmodified OLED. The difference in anodic buffer thickness dependent Device performance for both types of WO3 films is determined by the electrical property.
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enhanced performance of organic light Emitting Device by insertion of conducting insulating wo3 anodic buffer layer
Synthetic Metals, 2005Co-Authors: Masayuki Yahiro, Kenji Ishida, Hirofumi Yamada, Kazumi MatsushigeAbstract:Abstract Tungsten oxide (WO3) ultrathin film with high optical transparency is deposited on indium–tin oxide glass as hole injection layer of organic light Emitting Device (OLED). As-deposited WO3 film is amorphous and insulating, wherein the buffer thickness of 0.5 nm shows enhancement of hole injection in OLED. The Device performance is further enhanced after the as-deposited WO3 film is thermally treated, which is ascribed to lowering of the effective energy barrier height for hole injection. The annealed buffer layer is identified to be a semiconductor with crystalline structure. Although the thickness of the annealed WO3 buffer layer is up to 1.5 nm, the Device performance is still better than that of unmodified OLED. The difference in anodic buffer thickness dependent Device performance for both types of WO3 films is determined by the electrical property.
Xiaohong Zhang - One of the best experts on this subject based on the ideXlab platform.
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remanagement of singlet and triplet excitons in single emissive layer hybrid white organic light Emitting Devices using thermally activated delayed fluorescent blue exciplex
Advanced Materials, 2015Co-Authors: Zhan Chen, Xiaohong Zhang, Jian Qing, Wenjun Zhang, Bo WuAbstract:: A high-performance hybrid white organic light-Emitting Device (WOLED) is demonstrated based on an efficient novel thermally activated delayed fluorescence (TADF) blue exciplex system. This Device shows a low turn-on voltage of 2.5 V and maximum forward-viewing external quantum efficiency of 25.5%, which opens a new avenue for achieving high-performance hybrid WOLEDs with simple structures.
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management of singlet and triplet excitons in a single emission layer a simple approach for a high efficiency fluorescence phosphorescence hybrid white organic light Emitting Device
Advanced Materials, 2012Co-Authors: Jun Ye, Caijun Zheng, Xuemei Ou, Xiaohong Zhang, Mankeung FungAbstract:: A high-efficiency single-emission-layer (EML) hybrid white organic light Emitting Device is fabricated based on an ideal sky-blue fluorophor, DADBT, using a novel doping concentration regulation strategy, which effectively separates and respectively utilizes the singlet and triplet excitons in the single-EML. The white Device shows excellent electroluminescence performance with maximum total efficiencies of 26.6%, 53.5 cd A(-1) and 67.2 lm W(-1) .
Vladimir Bulovic - One of the best experts on this subject based on the ideXlab platform.
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air stable operation of transparent colloidal quantum dot based leds with a unipolar Device architecture
Nano Letters, 2010Co-Authors: Vanessa Wood, Moungi G Bawendi, Matthew J Panzer, Jeanmichel Caruge, Jonathan E Halpert, Vladimir BulovicAbstract:We report a novel unipolar light-Emitting Device architecture that operates using direct-current, field-driven electroluminescence of colloidally synthesized quantum dots (QDs). This Device architecture, which is based only on transparent ceramics and QDs, enables emission from different color QDs and, for the first time, constant QD electroluminescence during extended operation in air, unpackaged.
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a surface Emitting vacuum deposited organic light Emitting Device
Applied Physics Letters, 1997Co-Authors: Vladimir Bulovic, Stephen R Forrest, Peifang Tian, P E Burrows, M R Gokhale, Mark E ThompsonAbstract:We demonstrate a vacuum-deposited organic light Emitting Device which emits from its top surface through a transparent indium-tin-oxide anode. This Device employs a novel protective cap layer which prevents damage to the organic layers during sputter deposition of the anode, while also improving hole injection. Mechanisms of current transport and carrier injection from the contacts are investigated. This Device configuration allows for integration of organic light Emitting Devices with n-channel field effect transistors used in display active matrix backplanes.
Mark E Thompson - One of the best experts on this subject based on the ideXlab platform.
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a surface Emitting vacuum deposited organic light Emitting Device
Applied Physics Letters, 1997Co-Authors: Vladimir Bulovic, Stephen R Forrest, Peifang Tian, P E Burrows, M R Gokhale, Mark E ThompsonAbstract:We demonstrate a vacuum-deposited organic light Emitting Device which emits from its top surface through a transparent indium-tin-oxide anode. This Device employs a novel protective cap layer which prevents damage to the organic layers during sputter deposition of the anode, while also improving hole injection. Mechanisms of current transport and carrier injection from the contacts are investigated. This Device configuration allows for integration of organic light Emitting Devices with n-channel field effect transistors used in display active matrix backplanes.