The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Hideo Hosono - One of the best experts on this subject based on the ideXlab platform.
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low threshold voltage and Carrier Injection properties of inverted organic light emitting diodes with ca24al28o64 4 4e cathode and cu2 xse anode
Journal of Physical Chemistry C, 2009Co-Authors: Hiroshi Yanagi, Kibeom Kim, Ikue Koizumi, Maiko Kikuchi, Hidenori Hiramatsu, Masashi Miyakawa, Toshio Kamiya, Masahiro Hirano, Hideo HosonoAbstract:Carrier Injection properties including threshold voltages of inverted top-emission organic light-emitting diodes (ITOLED) were improved by applying room temperature stable electride [Ca24Al28O64]4+...
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low threshold voltage and Carrier Injection properties of inverted organic light emitting diodes with ca24al28o64 4 4e cathode and cu2 xse anode
Journal of Physical Chemistry C, 2009Co-Authors: Hiroshi Yanagi, Ikue Koizumi, Maiko Kikuchi, Hidenori Hiramatsu, Masashi Miyakawa, Toshio Kamiya, Masahiro Hirano, Hideo HosonoAbstract:Carrier Injection properties including threshold voltages of inverted top-emission organic light-emitting diodes (ITOLED) were improved by applying room temperature stable electride [Ca24Al28O64]4+(4e−) (C12A7:e−), which has a low work function of ∼2.4 eV, and a p-type degenerated semiconductor Cu2−xSe to bottom cathode and top anode buffer layers, respectively. The formation of a low-barrier electron Injection contact between C12A7:e− and tris(8-hydroxyqunoline)aluminum (Alq3) is demonstrated by the current−voltage characteristics of electron-only devices, as well as by photoelectron spectroscopy. The threshold voltage of the ITOLED is reduced by changing the bottom cathode from Al to C12A7:e− from 9 to 7.6 V at 10 mA cm−2. A 5 nm thick Cu2−xSe top anode buffer layer, deposited at room temperature, reduced the threshold voltage further to ∼2 V. The luminance efficiency of ITOLED with a Cu2−xSe buffer layer is nearly twice as large as that without the buffer layer. We emphasize that developing new electro...
Chihaya Adachi - One of the best experts on this subject based on the ideXlab platform.
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liquid carbazole substituted with a poly ethylene oxide group and its application for liquid organic light emitting diodes
Chemistry Letters, 2012Co-Authors: Korefumi Kubota, Shuzo Hirata, Yuki Shibano, Osamu Hirata, Masayuki Yahiro, Chihaya AdachiAbstract:We report efficient Carrier Injection characteristics in liquid organic light-emitting diodes (OLEDs). The use of a liquid carbazole substituted with a poly(ethylene oxide) (PEO) chain provided a s...
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analyzing bipolar Carrier transport characteristics of diarylamino substituted heterocyclic compounds in organic light emitting diodes by probing electroluminescence spectra
Chemistry of Materials, 2008Co-Authors: Kyung Soo Son, Masayuki Yahiro, Toshiro Imai, Hiroki Yoshizaki, Chihaya AdachiAbstract:We analyzed bipolar Carrier transport characteristics of diarylamino-substituted heterocyclic compounds (DAHCs) having benzene, pyridine, pyrimidine, or triazine electron-accepting core units and carbazole or β-naphthylamine as electron-donating substituents. The highest occupied molecular and lowest unoccupied molecular orbital levels, Carrier Injection, and transport characteristics were systematically controlled by changing combinations of the core and substituent units. By analyzing electroluminescence spectra as a probe in four kinds of organic light emitting diode (OLED) structures, we found that the Carrier transport characteristics of DAHCs significantly change depending on device structure. We concluded that all DAHCs have bipolar Carrier transport characteristics, that is, DAHCs intrinsically possess both hole and electron mobilities that are based on unique molecular structures having both electron-donating and -accepting units. We also demonstrated that Carrier Injection barriers between DAHCs...
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extremely high density Carrier Injection and transport over 12000a cm2 into organic thin films
Applied Physics Letters, 2005Co-Authors: Hidetoshi Yamamoto, Hiroki Kasajima, Wataru Yokoyama, Hiroyuki Sasabe, Chihaya AdachiAbstract:We achieved extremely-high-density steady state Carrier Injection and transport at over ∼10000A∕cm2 into organic thin films using high thermally conductive substrates, which suppress the temperature rise inside the devices by transferring the joule heat into the substrates. Using a silicon substrate with a high thermal conductivity of 148W∕mK and a small size cathode with a radius of r=25μm, we achieved a maximum current density of Jmax=12222A∕cm2 and power density of Pmax∼105W∕cm2 in an ITO(110nm)∕copperphthalocyanine (CuPc) (25nm)∕MgAg(100nm)∕Ag(10nm) device during a fraction of a second under direct current sweep. Further, we also achieved Jmax=514A∕cm2 in a conventional organic light-emitting diode structure using the same techniques. In the CuPc based devices, we observed characteristic current density (J)–voltage (V) behavior, indicating that the J–V characteristics are controlled by the trap-free space-charge-limited currents in the high current region, and by the trapped-charge-limited current in ...
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amplified spontaneous emission under optical pumping from an organic semiconductor laser structure equipped with transparent Carrier Injection electrodes
Applied Physics Letters, 2004Co-Authors: Hidetoshi Yamamoto, Hiroyuki Sasabe, Takahito Oyamada, Chihaya AdachiAbstract:We succeeded in observing amplified spontaneous emissions (ASEs) from an organic semiconductor laser structure equipped with transparent Carrier Injection electrodes under optical pumping. We employed a transparent indium-tin-oxide (ITO) anode and cathode, which significantly minimized light propagation loss compared with that in conventional metal electrodes. In particular, we incorporated an ultrathin MgAg layer between the organic electron transport layer and ITO cathode to enhance electron Injection efficiency, while maintaining low light propagation loss, and also to protect the organic layer from plasma damage when forming the ITO. By optically pumping the ITO [30 nm]/4,4′-bis[N(1-naphthyl)-N-phenyl-amino]biphenyl (α-NPD) [20 nm]/ 4,4′-di(N-carbazolyl)biphenyl (CBP) doped with 1,4-dimethoxy-2,5-bis[p-{N-phenyl-N(m-tolyl)amino}styryl]benzene (BSB) [70 nm]/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) [20 nm]/tris-(8-hydroxy-quinoline)aluminum (Alq3) [20 nm]/MgAg [2.5 nm]/ITO [20 nm] device, a l...
Hiroshi Yanagi - One of the best experts on this subject based on the ideXlab platform.
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low threshold voltage and Carrier Injection properties of inverted organic light emitting diodes with ca24al28o64 4 4e cathode and cu2 xse anode
Journal of Physical Chemistry C, 2009Co-Authors: Hiroshi Yanagi, Kibeom Kim, Ikue Koizumi, Maiko Kikuchi, Hidenori Hiramatsu, Masashi Miyakawa, Toshio Kamiya, Masahiro Hirano, Hideo HosonoAbstract:Carrier Injection properties including threshold voltages of inverted top-emission organic light-emitting diodes (ITOLED) were improved by applying room temperature stable electride [Ca24Al28O64]4+...
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low threshold voltage and Carrier Injection properties of inverted organic light emitting diodes with ca24al28o64 4 4e cathode and cu2 xse anode
Journal of Physical Chemistry C, 2009Co-Authors: Hiroshi Yanagi, Ikue Koizumi, Maiko Kikuchi, Hidenori Hiramatsu, Masashi Miyakawa, Toshio Kamiya, Masahiro Hirano, Hideo HosonoAbstract:Carrier Injection properties including threshold voltages of inverted top-emission organic light-emitting diodes (ITOLED) were improved by applying room temperature stable electride [Ca24Al28O64]4+(4e−) (C12A7:e−), which has a low work function of ∼2.4 eV, and a p-type degenerated semiconductor Cu2−xSe to bottom cathode and top anode buffer layers, respectively. The formation of a low-barrier electron Injection contact between C12A7:e− and tris(8-hydroxyqunoline)aluminum (Alq3) is demonstrated by the current−voltage characteristics of electron-only devices, as well as by photoelectron spectroscopy. The threshold voltage of the ITOLED is reduced by changing the bottom cathode from Al to C12A7:e− from 9 to 7.6 V at 10 mA cm−2. A 5 nm thick Cu2−xSe top anode buffer layer, deposited at room temperature, reduced the threshold voltage further to ∼2 V. The luminance efficiency of ITOLED with a Cu2−xSe buffer layer is nearly twice as large as that without the buffer layer. We emphasize that developing new electro...
Tatsuya Ryowa - One of the best experts on this subject based on the ideXlab platform.
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photoelectrochemical investigation of charge Injection efficiency for quantum dot light emitting diode
Applied Physics Letters, 2021Co-Authors: Keisuke Kitano, Yusuke Sakakibara, Masashi Kago, Takahiro Doe, Masaya Ueda, Tatsuya RyowaAbstract:When we applied colloidal quantum dots (QDs) for quantum dot light emitting diodes, it was well known that shell thickness played an important role in core protection, confinement of electrons and holes, and charge Injection efficiency. However, although the shell thickness dependence of electroluminescence properties was reported, Carrier Injection efficiency has not been discussed in detail. In this paper, we investigated the effect of shell thickness on the Carrier Injection efficiency that was evaluated by photoelectrochemical measurements. By comparing the product of internal quantum yield of photoluminescence and the evaluated Carrier Injection efficiency with external quantum efficiency (EQE) for QDs with various shell thicknesses, we found that the optimal shell thickness for increasing EQE is determined by the balance between protection of QD's surface and Carrier Injection efficiency.
Toshio Kamiya - One of the best experts on this subject based on the ideXlab platform.
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low threshold voltage and Carrier Injection properties of inverted organic light emitting diodes with ca24al28o64 4 4e cathode and cu2 xse anode
Journal of Physical Chemistry C, 2009Co-Authors: Hiroshi Yanagi, Kibeom Kim, Ikue Koizumi, Maiko Kikuchi, Hidenori Hiramatsu, Masashi Miyakawa, Toshio Kamiya, Masahiro Hirano, Hideo HosonoAbstract:Carrier Injection properties including threshold voltages of inverted top-emission organic light-emitting diodes (ITOLED) were improved by applying room temperature stable electride [Ca24Al28O64]4+...
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low threshold voltage and Carrier Injection properties of inverted organic light emitting diodes with ca24al28o64 4 4e cathode and cu2 xse anode
Journal of Physical Chemistry C, 2009Co-Authors: Hiroshi Yanagi, Ikue Koizumi, Maiko Kikuchi, Hidenori Hiramatsu, Masashi Miyakawa, Toshio Kamiya, Masahiro Hirano, Hideo HosonoAbstract:Carrier Injection properties including threshold voltages of inverted top-emission organic light-emitting diodes (ITOLED) were improved by applying room temperature stable electride [Ca24Al28O64]4+(4e−) (C12A7:e−), which has a low work function of ∼2.4 eV, and a p-type degenerated semiconductor Cu2−xSe to bottom cathode and top anode buffer layers, respectively. The formation of a low-barrier electron Injection contact between C12A7:e− and tris(8-hydroxyqunoline)aluminum (Alq3) is demonstrated by the current−voltage characteristics of electron-only devices, as well as by photoelectron spectroscopy. The threshold voltage of the ITOLED is reduced by changing the bottom cathode from Al to C12A7:e− from 9 to 7.6 V at 10 mA cm−2. A 5 nm thick Cu2−xSe top anode buffer layer, deposited at room temperature, reduced the threshold voltage further to ∼2 V. The luminance efficiency of ITOLED with a Cu2−xSe buffer layer is nearly twice as large as that without the buffer layer. We emphasize that developing new electro...