Article
Chemistry, Physical
Daniel Vong, Tahereh Nematiaram, Makena A. Dettmann, Tucker L. Murrey, Lucas S. R. Cavalcante, Sadi M. Gurses, Dhanya Radhakrishnan, Luke L. Daemen, John E. Anthony, Kristie J. Koski, Coleman X. Kronawitter, Alessandro Troisi, Adam J. Moule
Summary: The study demonstrates that relying on calculations from only the Gamma-point instead of the full Brillouin zone may overestimate a in small molecule semiconductors by up to 28%. Additionally, mode analysis reveals that no single mode dominates the phonon spectrum, highlighting the need to develop design rules considering the full spectrum of phonon modes.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Masaki Kunihiro, Eigo Shimaoka, Shuhei Morishita, Noriaki Tsurumachi, Masahiro Funahashi
Summary: We synthesized chiral dimeric chiral nematic (N*) liquid crystals with tri(p-phenylene vinylene) units. The mixture of dimeric compounds and monomeric chiral liquid crystals exhibited a glassy N* phase at room temperature, with the reflection band tunable by temperature change. High quality circularly polarized emission with a dissymmetry factor of 1.4 was observed when the reflection band covered the fluorescence peak. Hole mobilities were determined using the TOF method and analyzed using the Gaussian disorder model. The preexponential factors in the N* phase of these compounds were higher than those of amorphous organic semiconductors, attributed to the large pi-conjugated units.
MATERIALS ADVANCES
(2022)
Article
Materials Science, Multidisciplinary
Eigo Shimaoka, Masaki Kunihiro, Masahiro Funahashi
Summary: Oligo(p-phenylenevinylene)-based chiral nematic liquid crystals were synthesized and showed tunable reflection band for circularly polarized fluorescence. The glassy chiral nematic films exhibited left-handed circularly polarized light at room temperature.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Vinod Kumar Vishwakarma, Mrinmoy Roy, Rajan Singh, Doddamane Sreenivasamurthy Shankar Rao, Roy Paily, Achalkumar Ammathnadu Sudhakar
Summary: We designed and synthesized four liquid-crystalline derivatives based on naphthalene and perylene bisimide with imidazole-containing groups. These compounds with 10 flexible peripheral chains possess liquid crystallinity and solution processability, suitable for use as organic semiconductors. They showed different columnar phases and exhibited higher thermal stability and lower band gaps. The NI derivatives showed larger Stokes shifts, while the PI derivatives exhibited very high molar extinction coefficients. Two solution-processable liquid-crystalline compounds (NI-12 and PI-12) were used to fabricate organic field-effect transistors, with NI-12 derivatives showing a hole mobility of 1.99 cm2/V center dot s and PI-12 derivatives showing a hole mobility of 0.63 cm2/V center dot s at room temperature in normal air conditions.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Masashi Mamada, Hajime Nakanotani, Chihaya Adachi
Summary: This study reports structure-property relationships in a series of oligo(p-phenylenevinylene) derivatives, revealing significant effects on crystal packing, emission properties, and lasing behavior by substitution with cyano groups.
MATERIALS ADVANCES
(2021)
Article
Multidisciplinary Sciences
Lin Tao, Lixiang Han, Qian Yue, Bin Yao, Yujue Yang, Nengjie Huo
Summary: Carrier mobility is a crucial figure of merit for materials, with graphene having high mobility but zero bandgap, while transition-metal dichalcogenides have a sizable bandgap but limited mobility. Recent developments in 2D tellurium materials show high mobility and moderate bandgap, but air-stability remains a challenge. A new method using physical vapour deposition (PVD) has successfully produced air-stable tellurium flakes and wires with high hole mobility, opening up possibilities for high-performance optoelectronics.
ROYAL SOCIETY OPEN SCIENCE
(2021)
Article
Chemistry, Physical
Taehyun Won, Shohei Kumagai, Naotaka Kasuya, Yu Yamashita, Shun Watanabe, Toshihiro Okamoto, Jun Takeya
Summary: The chemical structures and morphologies of organic semiconductors (OSCs) and gate dielectrics were studied to improve the electrical performances of organic thin-film transistors (OTFTs). The charge transport properties at individual interfaces between the OSC surface and different gate dielectrics were investigated using solid and ionic gel gate dielectrics on the lower and upper surfaces of OSCs. The dual-gate transistor operation with solid/ionic gel gate exhibited improved hole mobility, attributed to the electric double layer formed at the ionic gel/uniform crystal surface.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Review
Chemistry, Multidisciplinary
Boyu Peng, Ruihan Wu, Hanying Li
Summary: Organic semiconductor (OSC) single crystals are promising for flexible electronic/optoelectronic applications due to their high mobility and intrinsic flexibility, but challenges arise in forming large, uniform, and defect-free single crystals. The droplet-pinned crystallization (DPC) method developed in 2012 offers a time- and cost-effective way to grow high-quality OSC single crystals, accelerating studies on charge-transport mechanisms and addressing the general lagging of electron mobility in OSC materials. The method allows flexibility in OSC materials and solvents, facilitating the formation of single-crystal OSC heterojunctions with promising potentials in circuits, photovoltaics, and photodiodes.
ACCOUNTS OF CHEMICAL RESEARCH
(2021)
Article
Chemistry, Physical
Yanqi Luo, Ramesh Kumar Chitumalla, So-Yeon Ham, Deniz N. Cakan, Taewoo Kim, Sanghyun Paek, Ying Shirley Meng, Joonkyung Jang, David P. Fenning, Min-cheol Kim
Summary: This study presents a simple approach to enhance the performance and stability of hybrid organic-inorganic perovskite solar cells (PSCs) by substituting the carbon atom in the common hole transport material with silicon. The modified material leads to increased hole mobility, improved charge extraction, and enhanced stability by blocking metal ion migration.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Physical
Finn Schulz, Shun Takamaru, Tobias Bens, Jun-ichi Hanna, Biprajit Sarkar, Sabine Laschat, Hiroaki Iino
Summary: This study synthesized and characterized three novel azulene-thiophene hybrid materials, and prepared uniformly flat films using the liquid crystalline phase. The thin films exhibited high mobilities in organic field effect transistors.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Satoru Inoue, Kiyoshi Nikaido, Toshiki Higashino, Shunto Arai, Mutsuo Tanaka, Reiji Kumai, Seiji Tsuzuki, Sachio Horiuchi, Haruki Sugiyama, Yasutomo Segawa, Kiyofumi Takaba, Saori Maki-Yonekura, Koji Yonekura, Tatsuo Hasegawa
Summary: The study develops solution-processable organic semiconductors based on unsymmetric substitution of BTBT, showcasing formation of distinctive solid crystalline phases when substituents are similar, and bilayer-type crystalline phase when substituents are unsymmetrical. Controllable various phases are demonstrated in layered organic semiconductors through correlation and competition among different packing structures.
CHEMISTRY OF MATERIALS
(2022)
Article
Multidisciplinary Sciences
Jiabiao Chen, Zhaochao Liu, Xinyue Dong, Zhansheng Gao, Yuxuan Lin, Yuyu He, Yingnan Duan, Tonghuai Cheng, Zhengyang Zhou, Huixia Fu, Feng Luo, Jinxiong Wu
Summary: Ultrathin Bi2SiO5 crystals grown by chemical vapor deposition (CVD) serve as excellent gate dielectric layers for 2D semiconductors, exhibiting high dielectric constant and large band gap. Vertically grown Bi2SiO5 can be easily transferred onto other substrates, facilitating ideal van der Waals integration with few-layer MoS2.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Toshiki Higashino, Satoru Inoue, Shunto Arai, Hiroyuki Matsui, Naoya Toda, Sachio Horiuchi, Reiko Azumi, Tatsuo Hasegawa
Summary: This study demonstrates that engineered end-cap substitution can achieve well-ordered two-dimensional molecular packing for high-performance organic semiconductors. By developing phenyl- and decyl-substituted compounds, layered single-crystalline thin-film transistors with high hole mobility were successfully fabricated.
CHEMISTRY OF MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Jiamin Sun, Xinming Zhuang, Yibo Fan, Shuai Guo, Zichao Cheng, Dong Liu, Yanxue Yin, Yufeng Tian, Zhiyong Pang, Zhipeng Wei, Xiufeng Song, Lei Liao, Feng Chen, Johnny C. Ho, Zai-xing Yang
Summary: In this research, an efficient strategy using metal-semiconductor junction to enhance the hole mobility of p-channel devices was proposed. By depositing CMOS-compatible metals on the surface of GaSb nanowire field-effect transistors, the peak hole mobility was increased threefold. This approach was also effective for other p-channel devices like GaAs and WSe2, resulting in improved performance for CMOS inverters.
Article
Chemistry, Physical
Youngchan Kim, Euihoon Jeong, Minwoong Joe, Changgu Lee
Summary: 2D semiconducting materials offer promising features for electronic device applications, but face challenges such as low charge-carrier mobility. A new synthesis method has been proposed to achieve high performance single crystalline 2D Bi2S3, showing potential for advanced electronic device applications.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Physics, Applied
Hironao Sasaki, Norihiko Kamata, Zentaro Honda, Takeshi Yasuda
APPLIED PHYSICS EXPRESS
(2019)
Article
Physics, Applied
Hiroki Iwaizumi, Tomotsugu Sugano, Takeshi Yasuda, Yukihiro Shimoi, Wataru Kobayashi, Yutaka Moritomo
JAPANESE JOURNAL OF APPLIED PHYSICS
(2019)
Article
Materials Science, Multidisciplinary
Chie Tanaka, Junpei Kuwabara, Takeshi Yasuda, Takaki Kanbara
Article
Physics, Applied
Takeshi Yasuda, Kenji Sakamoto
JAPANESE JOURNAL OF APPLIED PHYSICS
(2020)
Article
Nanoscience & Nanotechnology
Kirill Bulgarevich, Kenji Sakamoto, Takeshi Yasuda, Takeo Minari, Masayuki Takeuchi
ADVANCED ELECTRONIC MATERIALS
(2020)
Article
Physics, Applied
Hiroki Iwaizumi, Dai Inoue, Takeshi Yasuda, Yutaka Moritomo
Summary: The thermal coefficient alpha of the redox potential is crucial for thermal energy harvesting. A strong correlation has been observed between alpha and the number of active atoms (N-active) in conjugated polymers, which significantly impact the configuration entropy of surrounding solvent molecules.
APPLIED PHYSICS EXPRESS
(2021)
Article
Chemistry, Organic
Sachie Yamamoto, Zong Yang Zhou, Goki Hiruta, Katsuhiko Takeuchi, Jun-Chul Choi, Takeshi Yasuda, Takaki Kanbara, Junpei Kuwabara
Summary: The Povarov reaction is an efficient tool for the synthesis of aza-polycyclic aromatic hydrocarbons, with site selectivity depending on the HOMO distribution of the intermediate. Specific molecular structures can be synthesized through the Povarov reaction, with one derivative showing good performance as a hole-blocking material in organic light-emitting diodes.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Polymer Science
Ryota Iwamori, Ryota Sato, Junpei Kuwabara, Takeshi Yasuda, Takaki Kanbara
Summary: The polyaddition via the Co-catalyzed hydroarylation of 1-(2-pyrimidinyl)pyrrole with aromatic diynes to afford poly(arylenevinylene)s under mild conditions avoids production of stoichiometric amounts of by-products. Structural analysis of the obtained polymers reveals the presence of 1,1-vinylidene unit, but changing the counter anion of the Co catalyst and steric hindrance of the diyne monomers improves regioselectivity to form 1,2-vinylene linkages dominantly. The impact of regioselectivity on the optical and semiconducting properties of the polymers is also evaluated.
MACROMOLECULAR RAPID COMMUNICATIONS
(2021)
Article
Polymer Science
Hiroki Murakami, Kyoya Kobayashi, Keita Suzuki, Takeshi Yasuda, Takaki Kanbara, Junpei Kuwabara
Summary: This study focused on the metal-free synthesis of conjugated polymers containing azine bonds in their main chains. A two-step reaction was found to be effective for obtaining high-molecular-weight polymers through dehydration condensation of dialdehyde monomers and hydrazine. The synthesized azine-based polymers with fused thiophene skeletons serve as p-type semiconducting materials for organic field-effect transistors and organic photovoltaics, showing potential for green synthesis and applications in organic electronics.
Article
Chemistry, Multidisciplinary
Sachie Yamamoto, Takeshi Yasuda, Takaki Kanbara, Junpei Kuwabara
Summary: This study demonstrates the facile synthesis of 1,7-phenanthroline derivatives and investigates their performance as hole-blocking materials in OLEDs, providing insights into their molecular design for material applications.
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
(2022)
Article
Materials Science, Multidisciplinary
Junpei Kuwabara, Ryuya Kawasaki, Takeshi Yasuda, Takaki Kanbara
Summary: Judicious utilization of hydrogen bonding in diketopyrrolopyrroles allows smooth carrier transfer in organic semiconducting materials. The study demonstrates the formation of a hydrogen-bonded dimer structure in the solid state, which is suitable for carrier-transport pathway.
Article
Materials Science, Multidisciplinary
Naoki Onda, Ryota Sato, Junpei Kuwabara, Takeshi Yasuda, Takaki Kanbara
Summary: Polycondensation reaction of 1,2,4,5-tetrafluorobenzene (1) and 3,3'-dihexyl-2,2'-bithiophene was examined via Pd/Ag dual-catalyzed cross-dehydrogenative coupling. In situ deprotonation-metalation of 1 with Ag salt followed by transmetalation with a Pd catalyst successfully produced a cross-coupling product. The one-pot two-step reaction method effectively prevented undesired homo-coupling defects during polymerization. The resulting highly regioregular polymer exhibited a packed structure and strong fluorescence in the film state, showing potential as an emitting material in organic light-emitting diodes.
Article
Materials Science, Multidisciplinary
Kenji Sakamoto, Kirill Bulgarevich, Takeshi Yasuda, Takeo Minari, Masayuki Takeuchi
Summary: The origin of intrinsic operational instability in organic field-effect transistors (OFETs) is discussed by comparing bias stress effects of OFETs with unidirectionally aligned and unaligned active layers of two different semiconducting polymers under vacuum environment. The results indicate that an increase in mobility does not necessarily lead to an increase in operational stability.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Junko Aimi, Takeshi Yasuda, Chih-Feng Huang, Masafumi Yoshio, Wen-Chang Chen
Summary: In this study, solution-processed organic field-effect transistor (OFET) memory devices were fabricated using a special blend film preparation method. The resulting devices showed good charge carrier mobility and on/off current ratio, as well as substantial reversible threshold shift and long charge retention ability.
MATERIALS ADVANCES
(2022)
Article
Chemistry, Multidisciplinary
Shihao Liu, Ying-Chiao Wang, Chi-Ming Chang, Takeshi Yasuda, Naoya Fukui, Hiroaki Maeda, Peihua Long, Kazuo Nakazato, Wen-Bin Jian, Wenfa Xie, Kazuhito Tsukagoshi, Hiroshi Nishihara
