Research
- Organic devices and OLEDs
- Molecular orientation in amorphous films
- Effects of orientation on device performances
- For future development
Member
Publications etc.
Messages
Link
- Reseach Center for Organic Electronics (ROEL), Yamagata Univ.
- Program of the Fostering of Distinguished Young Researchers
- Faculty of Engineering/Department of Science and Engineering
Contact
TEL&FAX +81-238-26-3890
e-mail d_yokoyama(at)yz.yama
gata-u.ac.jp
add 4-3-16 Johnan, Yonezawa, Yamagata 992-8510, Japan
PAPERS
2024
- 58.
- A novel matrix-free hyperfluorescent system based on anti-quenching TADF host for high color purity MR-TADF emitters
Adv. Mater. 37, 2409746 (2024)
Dehao Jiang, Hisahiro Sasabe, Yuhui Chen, Yuki Sagae, Hiroki Sato, Daisuke Yokoyama, Hiroshi Katagiri, Junji Kido
- 57.
- Angular distribution analysis of permanent dipole moments in amorphous organic semiconductor film with large spontaneous orientation polarization
J. Phys. Chem. C 128, 6072-6079 (2024)
Yuro Yagi, Yutaka Noguchi, Daisuke Yokoyama
- 56.
- Fundamental guidelines for the active control of the molecular orientation of heteroleptic iridium complexes enabled by carbazole-based host materials
J. Mater. Chem. C 12, 2772-2779 (2024)
Hiroki Arai, Naoto Yoshida, Hisahiro Sasabe, Yuki Sagae, Keigo Hoshi, Daisuke Yokoyama, Junji Kido
2023
- 55.
- Elucidating the horizontal orientation mechanism of emissive transition dipole moment in a series of stick-like delayed fluorescent emitters for ultra-high-efficiency OLEDs
Adv. Opt. Mater. 12, 2302382 (2023)
Naoto Yoshida, Hisahiro Sasabe, Hiroki Arai, Yuki Sagae, Yuro Yagi, Keigo Hoshi, Daisuke Yokoyama, Junji Kido
- 54.
- Robust spirobifluorene core based hole transporters with high mobility for long-life green phosphorescent organic light-emitting devices
Chem. Eur. J. 29, e202202636 (2023)
Natsuo Nagamura, Hisahiro Sasabe, Hiroki Sato, Nozomi Ito, Shoki Abe, Yoshihito Sukegawa, Daisuke Yokoyama, Hironori Kaji, Junji Kido
2022
- 53.
- Explicit analysis of functional group orientation in amorphous organic semiconductor films by using deuterated materials
J. Mater. Chem. C 10, 16761-16772 (2022)
Yoshihito Sukegawa, Yuro Yagi, Hideyoshi Kitahara, Shunji Mochizuki, Daisuke Yokoyama
- 52.
- A multifunctional hole-transporter for high-performance TADF OLEDs and clarification of factors governing the transport property by multiscale simulation
J. Mater. Chem. C 10, 8694-8701 (2022)
Natsuo Nagamura, Hisahiro Sasabe, Hiroki Sato, Takahiro Kamata, Nozomi Ito, Suguru Araki, Shoki Abe, Yoshihito Sukegawa, Daisuke Yokoyama, Hironori Kaji, Junji Kido
- 51.
- Four dibenzofuran-terminated high triplet energy hole-transporters for high-efficiency and long-life organic light-emitting devices
Chem. Eur. J. 28, e202104408 (2022)
Hisahiro Sasabe, Suguru Araki, Shoki Abe, Nozomi Ito, Kengo Kumada, Taito Noda, Yoshihito Sukegawa, Daisuke Yokoyama, Junji Kido
- 50.
- Model-free analysis of molecular orientation in amorphous organic semiconductor films for understanding its formation dynamics: methods and systematic investigation
Org. Electron. 100, 106377 (2022)
Yoshihito Sukegawa, Yoshiya Sakai, Daisuke Yokoyama
2021
- 49.
- Active refractive index control using a stably evaporable perfluororesin for high-outcoupling-efficiency organic light-emitting diodes
J. Mater. Chem. C 9, 11115-11125 (2021)
Daisuke Yokoyama, Tatsuki Sasaki, Yasutaka Suzuki, Takefumi Abe, Kaori Tsuruoka, Tatsuya Miyajima, Toshifumi Kakiuchi, Chiho Morita, Masaharu Aoki, Yasuhiro Ouchi, Wataru Aita, Yasuhiro Kuwana, Yutaka Noguchi
Selected as "Journal of Materials Chemistry C Hot Papers"
Selected as the front cover Website
- 48.
- Molecular orientation anisotropy and hole transport properties of diluted semiconducting films of poly(p-phenylenevinylene) derivative
Org. Electron. 96, 106246 (2021)
Seiya Demura, Tatsuro Endo, Takumi Ishii, Daisuke Yokoyama, Yutaka Noguchi
- 47.
- Effect of the conformer distribution on the properties of amorphous organic semiconductor films for organic light-emitting diodes
Phys. Chem. Chem. Phys. 23, 14242-14251 (2021)
Yoshihito Sukegawa, Kaito Sato, Wataru Fujiwara, Hiroshi Katagiri, Daisuke Yokoyama
2020
- 46.
- Significantly sensitized ternary blend polymer solar cells with very small content of narrow-bandgap third component that utilizes optical interference
Macromolecules 53, 10623-10635 (2020)
Masahiko Saito, Yasunari Tamai, Hiroyuki Ichikawa, Hiroyuki Yoshida, Daisuke Yokoyama, Hideo Ohkita, Itaru Osaka
- 45.
- Molecular orientations of delayed fluorescent emitters in a series of carbazole-based host materials
Front. Chem. 8, 427 (2020)
Hisahiro Sasabe, Yuki Chikayasu, Satoru Ohisa, Hiroki Arai, Tatsuya Ohsawa, Ryutaro Komatsu, Yuichiro Watanabe, Daisuke Yokoyama, Junji Kido
- 44.
- Simultaneous realization of high-efficiency, low-drive voltage, and long lifetime TADF OLEDs by multifunctional hole-transporters
J. Mater. Chem. C 8, 7200-7210 (2020)
Takahiro Kamata, Hisahiro Sasabe, Nozomi Ito, Yoshihito Sukegawa, Ayato Arai, Takayuki Chiba, Daisuke Yokoyama, Junji Kido
- 43.
- A terpyridine-modified chrysene derivative as an electron transporter to improve the lifetime in phosphorescent OLEDs
J. Mater. Chem. C 8, 3200-3205 (2020)
Tsukasa Owada, Hisahiro Sasabe, Yoshihito Sukegawa, Taiki Watanabe, Tomohiro Maruyama, Yuichiro Watanabe, Daisuke Yokoyama, Junji Kido
2019
- 42.
- Control of molecular orientation in organic semiconductor films using weak hydrogen bonds
Adv. Mater. 31, 1808300 (2019)
Yuichiro Watanabe, Daisuke Yokoyama, Tomoyuki Koganezawa, Hiroshi Katagiri, Takashi Ito, Satoru Ohisa, Takayuki Chiba, Hisahiro Sasabe, Junji Kido
2018
- 41.
- Air-stable and high-performance solution-processed organic light-emitting devices based on hydrophobic polymeric ionic liquid carrier-injection layers
Adv. Mater. 30, 1705915 (2018)
Shugo Sato, Satoru Ohisa, Yukihiro Hayashi, Ryo Sato, Daisuke Yokoyama, Tetsuya Kato, Michinori Suzuki, Takayuki Chiba, Yong-Jin Pu, Junji Kido
2017
- 40.
- Horizontally orientated stick-like emitters: Achieving enhancement of intrinsic out-coupling factor and
electroluminescence device performance
Chem. Mater. 29, 8630-8636 (2017)
Ming Liu, Ryutaro Komatsu, Xinyi Cai, Katsuyuki Hotta, Shugo Sato, Kunkun Liu, Dongcheng Chen, Yuki Kato, Hisahiro Sasabe, Satoru Ohisa, Yoshiyuki Suzuri, Daisuke Yokoyama, Shi-Jian Su, Junji Kido
- 39.
- Thermally activated delayed fluorescence OLEDs with fully solution processed organic layers exhibiting nearly 10% external quantum efficiency
Chem. Commun. 53, 2439-2442 (2017)
Ken Albrecht, Kenichi Matsuoka, Daisuke Yokoyama, Yoshiya Sakai, Akira Nakayama, Katsuhiko Fujita, Kimihisa Yamamoto
2016
- 38.
- Fundamental functions of peripheral and core pyridine rings in a series of bis-terpyridine derivatives for high-performance organic light-emitting devices
J. Mater. Chem. C 4, 8980-8988 (2016)
Yuichiro Watanabe, Ryo Yoshioka, Hisahiro Sasabe, Takahiro Kamata, Hiroshi Katagiri, Daisuke Yokoyama, Junji Kido
- 37.
- Syntheses, properties, and OLED characteristics of 2,2'-bipyridine-based electron-transport materials: synergistic effect of molecular shape anisotropy and a weak hydrogen-bonding network on molecular orientation
J. Mater. Chem. C 4, 3699-3704 (2016)
Yuichiro Watanabe, Hisahiro Sasabe, Daisuke Yokoyama, Teruo Beppu, Hiroshi Katagiri, Junji Kido
- 36.
- Excimer emission based on the control of molecular structure and intermolecular interactions
J. Mater. Chem. C 4, 2784-2792 (2016)
Jaehyun Lee, Hyocheol Jung, Hwangyu Shin, Joonghan Kim, Daisuke Yokoyama, Hidetaka Nishimura, Atsushi Wakamiya, Jongwook Park
- 35.
- A series of fluorinated phenylpyridine-based electron-transporters for blue phosphorescent OLEDs
J. Mater. Chem. C 4, 1104-1110 (2016)
Takahiro Kamata, Hisahiro Sasabe, Yuichiro Watanabe, Daisuke Yokoyama, Hiroshi Katagiri, Junji Kido
2015
- 34.
- Photopatterning of indomethacin thin films: a solvent-free vapor-deposited photoresist
ACS Appl. Mater. Interfaces 7, 23398-23401 (2015)
Katherine L. Camera, Jaritza Gomez-Zayas, Daisuke Yokoyama, Mark D. Ediger, Christopher K. Ober
- 33.
- Simple model-free estimation of orientation order parameters of vacuum-deposited and spin-coated amorphous films used in organic light-emitting diodes
Appl. Phys. Express 8, 096601 (2015)
Yoshiya Sakai, Maki Shibata, Daisuke Yokoyama
- 32.
- Advantages and disadvantages of vacuum-deposited and spin-coated amorphous organic semiconductor films for organic light-emitting diodes
J. Mater. Chem. C 3, 11178-11191 (2015) [PDF 3.8MB]
Maki Shibata, Yoshiya Sakai, Daisuke Yokoyama
- 31.
- Anisotropic materials in OLEDs for high outcoupling efficiency
Opt. Express 23, 21128-21148 (2015)
Michiel Koen Callens, Daisuke Yokoyama, Kristiaan Neyts
- 30.
- High fill factor and thermal stability of bilayer organic photovoltaic cells with an inverted structure
Appl. Phys. Lett. 106, 053305 (2015)
Zhongqiang Wang, Ziruo Hong, Taojun Zhuang, Guo Chen, Hisahiro Sasabe, Daisuke Yokoyama, Junji Kido
- 29.
- Extended-gate organic field-effect transistor for the detection of histamine in water
Jpn. J. Appl. Phys. 54, 04DK02 (2015)
Tsukuru Minamiki, Tsuyoshi Minami, Daisuke Yokoyama, Kenjiro Fukuda, Daisuke Kumaki, Shizuo Tokito
- 28.
- Simultaneous manipulation of intramolecular and intermolecular hydrogen bonds in n-type organic semiconductor layers: Realization of horizontal orientation in OLEDs
Adv. Opt. Mater. 3 769-773 (2015)
Yuichiro Watanabe, Hisahiro Sasabe, Daisuke Yokoyama, Teruo Beppu, Hiroshi Katagiri, Yong-Jin Pu, Junji Kido
2014
- 27.
- An extended-gate type organic field effect transistor functionalised by phenylboronic acid for saccharide detection in water
Chem. Commun. 50, 15613-15615 (2014)
Tsuyoshi Minami, Tsukuru Minamiki, Yuki Hashima, Daisuke Yokoyama, Tomohito Sekine, Kenjiro Fukuda, Daisuke Kumaki, Shizuo Tokito
- 26.
- Excimer formation in organic emitter films associated with a molecular orientation promoted by steric hindrance
Chem. Commun. 50, 14145-14148 (2014)
Jaehyun Lee, Beomjin Kim, Ji Eon Kwon, Joonghan Kim, Daisuke Yokoyama, Katsuaki Suzuki, Hidetaka Nishimura, Atsushi Wakamiya, Soo Young Park, Jongwook Park
- 25.
- Esterification of indoline-based small-molecule donors for efficient co-evaporated organic photovoltaics
J. Phys. Chem. C 118, 14785-14794 (2014)
Zhongqiang Wang, Xiao-Feng Wang, Daisuke Yokoyama, Hisahiro Sasabe, Junji Kido, Zhaoyang Liu, Wenjing Tian, Osamu Kitao, Toshitaka Ikeuchi, Shin-ichi Sasaki
- 24.
- Quantum yield in blue-emitting anthracene derivatives: vibronic coupling density and transition dipole moment density
Phys. Chem. Chem. Phys. 16, 14244-14256 (2014)
Motoyuki Uejima, Tohru Sato, Daisuke Yokoyama, Kazuyoshi Tanaka, Jongwook Park
2013
- 23.
- Synthesis and electroluminescence properties of highly efficient blue fluorescence emitters using dual core chromophores
J. Mater. Chem. C 1, 432-440 (2013)
Beomjin Kim, Youngil Park, Jaehyun Lee, Daisuke Yokoyama, Ji-Hoon Lee, Junji Kido, Jongwook Park
- 22.
- Highly efficient organic p-i-n photovoltaic cells based on tetraphenyldibenzoperiflanthene and fullerene C70
Energy Environ. Sci. 6, 249-255 (2013)
Zhongqiang Wang, Daisuke Yokoyama, Xiao-Feng Wang, Ziruo Hong, Yang Yang, Junji Kido
2012
- 21.
- Wide-range refractive index control of organic semiconductor films toward advanced optical design of organic optoelectronic devices
Adv. Mater. 24, 6368-6373 (2012)
Daisuke Yokoyama, Ken-ichi Nakayama, Toshiya Otani, Junji Kido
Selected as the back cover Website [PDF 2.5MB]
- 20.
- Optical and electrical properties of a squaraine dye in photovoltaic cells
Appl. Phys. Lett. 101, 083904 (2012)
Guo Chen, Daisuke Yokoyama, Hisahiro Sasabe, Ziruo Hong, Yang Yang, Junji Kido
- 19.
- Horizontal orientation of disk-like hole transport molecules and their application for organic light-emitting diodes requiring lower driving voltage
J. Phys. Chem. C 116, 8699-8706 (2012)
Jun-Yun Kim, Daisuke Yokoyama, Chihaya Adachi
- 18.
- Optimizing the charge balance of fluorescent organic light-emitting devices to achieve high external quantum efficiency beyond the conventional upper limit
Adv. Mater. 24, 1765-1770 (2012)
Yong-Jin Pu, Go Nakata, Fumiya Satoh, Hisahiro Sasabe, Daisuke Yokoyama, Junji Kido
- 17.
- High-efficiency simple planar heterojunction organic thin-film photovoltaics with horizontally oriented amorphous donors
Sol. Energy Mater. Sol. Cells 98, 472-475 (2012)
Daisuke Yokoyama, Zhong Qiang Wang, Yong-Jin Pu, Kenta Kobayashi, Junji Kido, Ziruo Hong
2011
- 16.
- Molecular orientation in small-molecule organic light-emitting diodes
Feature Article (invited review)
J. Mater. Chem. 21, 19187-19202 (2011) [PDF 4.0MB]
Daisuke Yokoyama
- 15.
- Dual efficiency enhancement by delayed fluorescence and dipole orientation in high-efficiency fluorescent organic light-emitting diodes
Appl. Phys. Lett. 99, 123303 (2011)
Daisuke Yokoyama, Youngil Park, Beomjin Kim, Sookang Kim, Yong-Jin Pu, Junji Kido, Jongwook Park
- 14.
- An integrated enzyme-linked immunosorbent assay system with an organic light-emitting diode and a charge-coupled device for fluorescence detection
J. Sep. Sci. 34, 2906-2912 (2011)
Hizuru Nakajima, Yukiko Okuma, Kazuhiro Morioka, Mayo Miyake, Akihide Hemmi, Tatsuya Tobita, Masayuki Yahiro, Daisuke Yokoyama, Chihaya Adachi, Nobuaki Soh, Koji Nakano, Shuhua Xue, Hulie Zeng, Katsumi Uchiyama, Toshihiko Imato
- 13.
- Molecular stacking induced by intermolecular C-H...N hydrogen bonds leading to high carrier mobility in vacuum-deposited organic films
Adv. Funct. Mater. 21, 1375-1382 (2011)
Daisuke Yokoyama, Hisahiro Sasabe, Yukio Furukawa, Chihaya Adachi, Junji Kido
- 12.
- Increased light outcoupling efficiency in dye-doped small molecule organic light-emitting diodes with horizontally oriented emitters
Org. Electron. 12, 809-817 (2011)
Jörg Frischeisen, Daisuke Yokoyama, Ayataka Endo, Chihaya Adachi, Wolfgang Brütting
- 11.
- Influence of substituted pyridine rings on physical properties and electron mobilities of 2-methylpyrimidine skeleton-based electron-transporters
Adv. Funct. Mater. 21, 336-342 (2011)
Hisahiro Sasabe, Daisaku Tanaka, Daisuke Yokoyama, Takayuki Chiba, Yong-Jin Pu, Ken-ichi Nakayama, Masaaki Yokoyama, Junji Kido
2010
- 10.
- In situ real-time spectroscopic ellipsometry measurement for the investigation of molecular orientation in organic amorphous multilayer structures
J. Appl. Phys. 107, 123512 (2010)
Daisuke Yokoyama, Chihaya Adachi
- 9.
- Determination of molecular dipole orientation in doped fluorescent organic thin films by photoluminescence measurements
Appl. Phys. Lett. 96, 073302 (2010)
Jörg Frischeisen, Daisuke Yokoyama, Chihaya Adachi, Wolfgang Brütting
- 8.
- Orientation control of linear-shaped molecules in vacuum-deposited organic amorphous films and its effect on carrier mobilities
Adv. Funct. Mater. 20, 386-391 (2010)
Daisuke Yokoyama, Yousuke Setoguchi, Akio Sakaguchi, Michio Suzuki, Chihaya Adachi
2009
- 7.
- Enhancement of electron transport by horizontal molecular orientation of oxadiazole planar molecules in organic amorphous films
Appl. Phys. Lett. 95, 243303 (2009)
Daisuke Yokoyama, Akio Sakaguchi, Michio Suzuki, Chihaya Adachi
- 6.
- Thermally activated delayed fluorescence from Sn4+-porphyrin complexes and their application to organic light emitting diodes - a novel mechanism for electroluminescence
Adv. Mater. 21, 4802-4806 (2009)
Ayataka Endo, Mai Ogasawara, Atsushi Takahashi, Daisuke Yokoyama, Yoshimine Kato, Chihaya Adachi
- 5.
- Horizontal orientation of linear-shaped organic molecules having bulky substituents in neat and doped vacuum-deposited amorphous films
Org. Electron. 10, 127-137 (2009)
Daisuke Yokoyama, Akio Sakaguchi, Michio Suzuki, Chihaya Adachi
Selected as the top 25 most cited articles since 2008 in Org. Electron. Website
2008
- 4.
- Horizontal molecular orientation in vacuum-deposited organic amorphous films of hole and electron transport materials
Appl. Phys. Lett. 93, 173302 (2008)
Daisuke Yokoyama, Akio Sakaguchi, Michio Suzuki, Chihaya Adachi
- 3.
- Spectrally narrow emissions at cutoff wavelength from edges of optically and electrically pumped organic anisotropic films
J. Appl. Phys. 103, 123104 (2008)
J. Appl. Phys. 104, 039909 (2008)
Daisuke Yokoyama, Masato Moriwake, Chihaya Adachi
~2007
- 2.
- Spectrally narrow emission at cutoff wavelength from edge of electrically pumped organic light-emitting diodes
Jpn. J. Appl. Phys. (Express Lett.), 46, L826-L829 (2007)
Daisuke Yokoyama, Hajime Nakanotani, Yousuke Setoguchi, Masato Moriwake, Dai Ohnishi, Masayuki Yahiro, Chihaya Adachi
- 1.
- Three distinct solvated structures of p-nitroaniline in acetonitrile/CCl4 mixed solvents
Bull. Chem. Soc. Jpn. 72, 389-395 (1999)
Kathaperumal Mohanalingam, Daisuke Yokoyama, Chihiro Kato, Hiro-o Hamaguchi