Review
Chemistry, Multidisciplinary
Xiaotong Zhao, Hantang Zhang, Jing Zhang, Jie Liu, Ming Lei, Lang Jiang
Summary: The study of organic semiconductor single crystal (OSSC) arrays has attracted considerable interest due to their potential applications in flexible displays, smart wearable devices, biochemical sensors, etc. Patterning of OSSCs is crucial for organic integrated circuits. Tremendous efforts have been devoted to the controllable preparation of OSSC arrays, and progress has been made. This review summarizes the strategies for patterning OSSCs, discusses the advantages and limitations of different methods, and highlights the challenges and advances in OSSC-based circuits and flexible devices.
Article
Physics, Applied
Fu-Xiang Rikudo Chen, Naoya Kawakami, Chang-Tsan Lee, Pen-Yuan Shih, Zi-Cheng Wu, Yong-Cheng Yang, Hao-Wei Tu, Wen-Bin Jian, Chenming Hu, Chun-Liang Lin
Summary: Transition metal dichalcogenides (TMDs), with only a few atoms thickness, are a potential solution for scaling down semiconductor devices. However, the carrier mobility in molybdenum disulfide (MoS2) field-effect transistors (FETs) is lower than expected due to defects. This study directly counts the defects in MoS2 FETs with varying carrier mobility and finds that both vacancies and impurities contribute to the decrease in carrier mobility.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Ab F. Nieuwenhuis, Daniel F. Duarte Sanchez, Jin Z. Cui, Serge G. Lemay
Summary: In this study, the quasi-1D electrical current through long single conjugated polymer chains was measured using coupled ionic-electronic charge transport. It was found that fluctuations between internal conformations of the individual polymers resulted in abrupt, multilevel switches in the electrical current, consistent with theoretical simulations. Additionally, the results provided insights into the dynamics of random-coil polymers and the potential use of semiconducting polymers as electrical labels for single-molecule sensing assays.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yue Xi, Tao Wang, Qi Mu, Congcong Huang, Shuming Duan, Xiaochen Ren, Wenping Hu
Summary: Organic field-effect transistors are fabricated with high-resolution organic single crystal arrays using a novel patterning method, demonstrating low off-state current, high on/off current ratio, and good device uniformity. These devices show potential for low-power or high-performance optical sensing applications and exhibit good frequency response at 20 kHz.
MATERIALS CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Wei Deng, Hemeng Lei, Xiujuan Zhang, Fangming Sheng, Jialin Shi, Xiali Zhang, Xinyue Liu, Souren Grigorian, Xiaohong Zhang, Jiansheng Jie
Summary: The study introduces an orientation filter funnel concept for scalable growth of organic single-crystal films, significantly increasing the average mobility of organic films and improving the uniformity of electrical properties, achieving a new lowest record in organic devices.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Itsuki Shoji, Hideki Wada, Kodai Uto, Yasunori Takeda, Toshiyuki Sugimoto, Hiroyuki Matsui
Summary: The passage introduces a novel quasi-static electric field sensor based on a floating extended gate organic field-effect transistor, which is highly sensitive, integrable as an array, ultra-flexible, highly expandable, and digitally printable. The sensor is used for detecting biological activities and provides a new vision of electric charges.
ADVANCED MATERIALS TECHNOLOGIES
(2021)
Article
Chemistry, Multidisciplinary
Jinwen Wang, Zheng Ren, Jing Pan, Xiaofeng Wu, Jiansheng Jie, Xiaohong Zhang, Xiujuan Zhang
Summary: For the first time, a method of anchored crystal-seed epitaxial growth is developed for wafer-scale growth of 2D organic semiconductor single crystals. The crystal seed is firmly anchored on the liquid surface, ensuring steady epitaxial growth. This approach effectively eliminates substrate defects and enhances the 2D growth of organic crystals, providing a new avenue for high-performance organic electronics.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Guy Reuveni, Yael Diskin-Posner, Christian Gehrmann, Shravan Godse, Giannis G. Gkikas, Isaac Buchine, Sigalit Aharon, Roman Korobko, Constantinos C. Stoumpos, David A. Egger, Omer Yaffe
Summary: We demonstrate that formamidinium-based crystals differ from methyl ammonium-based halide perovskite crystals due to the presence of intrinsic local static disorder in their inorganic sublattice, despite having a well-defined average crystal structure. Our study combines terahertz-range Raman scattering, single-crystal X-ray diffraction, and first-principles calculations to investigate the temperature-dependent dynamics of the inorganic sublattice in the range of 10-300 K. The temperature evolution of the Raman spectra reveals that low-temperature, local static disorder significantly influences the crystal structural dynamics and phase transitions at higher temperatures.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Shunsuke Yamamoto, Anastasios G. Polyravas, Sanggil Han, George G. Malliaras
Summary: This study examines the factors controlling the neuromorphic response of organic electrochemical transistors (OECTs) and highlights the dependence of post-synaptic response timescale on the size of ions in the electrolyte. Modeling further reveals that the transient response of the ionic circuit of the OECT controls the neuromorphic response. These findings provide insights for a more rational design of OECT-based neuromorphic devices.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Beibei Fu, Fangxu Yang, Lingjie Sun, Qiang Zhao, Deyang Ji, Yajing Sun, Xiaotao Zhang, Wenping Hu
Summary: This study develops a surface-assisted assembly strategy based on polymer modification to grow large-area organic single crystals on polymer substrates, demonstrating their potential in flexible electronics.
ADVANCED MATERIALS
(2022)
Article
Physics, Applied
Yiyang Luo, Kairong Huang, Xiaoci Liang, Hanjing Ke, Sujuan Hu, Qian Wu, Baiquan Liu, Chuan Liu
Summary: Vertical static induction transistors (SITs) have gained new attention due to their suitability for flexible substrates and hybrid integration with light-emitting diodes. However, understanding of them has been hindered by Schottky gate leakage. In this study, concise expressions for the channel potential and current-voltage characteristics of ideal SITs are derived, and the theory is verified through simulation and experimental results. The proposed theories connect the device structure and electrical characteristics of SITs concisely.
PHYSICAL REVIEW APPLIED
(2023)
Article
Nanoscience & Nanotechnology
Roman S. Fedorenko, Alexey Kuevda, Vasiliy A. Trukhanov, Vladislav G. Konstantinov, Audrey Yu Sosorev, Alina A. Sonina, Maxim S. Kazantsev, Nikolay M. Surin, Souren Grigorian, Oleg Borshchev, Sergey A. Ponomarenko, Dmitry Yu Paraschuk
Summary: 2D organic semiconductor single crystals have the potential to be used in ultrathin, flexible, and transparent field-effect devices. However, the light emissive properties of these crystals have not been reported, and achieving both high charge-carrier mobility and bright luminescence in one material is still a challenge. In this study, a high-mobility 2D organic semiconductor based on a BTBT-derivative is presented, which demonstrates both high charge-carrier mobility and prominent light emissive properties.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Physical
Lixin Li, Qingqing Zhao, Shuwen Chen, Zhiqun Lin, Juan Peng
Summary: The ability to control cocrystallization behavior through meticulous design and synthesis of multiblock copolymers can enhance charge transport properties, providing important guidance for the development of high-performance organic field-effect transistors (OFETs).
Article
Nanoscience & Nanotechnology
Taehoon Hwang, Eunyoung Park, Jungyoon Seo, Dashdendev Tsogbayar, Eun Ko, Chanwoo Yang, Hyungju Ahn, Dong Yun Lee, Hwa Sung Lee
Summary: This study investigates the correlation between organic field-effect transistors (OFETs) and organic charge-modulated field-effect transistors (OCMFETs) to improve the understanding of driving mechanisms in OCMFETs and optimize their device performance. By introducing self-assembled monolayers with different functional groups on the gate dielectric surface, the impact of surface characteristics on the electrical behavior of both devices is explored. The dipole moment of the dielectric surface is identified as a critical control variable in the performance correlation between OFET and OCMFET devices.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Fengjing Liu, Liang Wang, Jiawei Wang, Feng Wang, Yiyi Chen, Shuai Zhang, Huijuan Sun, Jia Liu, Gongtang Wang, Yuanyuan Hu, Chao Jiang
Summary: 2D Ruddlesden-Popper perovskites exhibit reliable field effect electrical characteristics at low temperatures, but ion migration and contact resistance seriously degrade device performance. While Schottky contacts at the metal/2D PVK interface can be improved by replacing materials, the out-of-plane mobility is three orders of magnitude lower than the in-plane mobility, causing significant interlayer transport resistance.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Shun Watanabe, Ryohei Hakamatani, Keita Yaegashi, Yu Yamashita, Han Nozawa, Mari Sasaki, Shohei Kumagai, Toshihiro Okamoto, Cindy G. Tang, Lay-Lay Chua, Peter K. H. Ho, Jun Takeya
Summary: A highly periodic electrostatic potential is crucial for coherent band electron systems in van der Waals bonded organic crystals. Impurity doping faces difficulties in molecular crystals due to the destruction of ordered molecular frameworks, but a versatile strategy allows for the creation of coherent 2D electronic carriers at the surface of organic semiconductor crystals while preserving precise molecular structures. By forming redox-active molecular dopants on a molecularly flat crystalline surface through a simple solution process, efficient chemical doping and high carrier density can be achieved at room temperature, resulting in excellent carrier transport properties and piezoresistive effects similar to those in bulk crystals.
Article
Chemistry, Physical
Shohei Kumagai, Craig P. Yu, Shunsuke Nakano, Tatsuro Annaka, Masato Mitani, Masafumi Yano, Hiroyuki Ishii, Jun Takeya, Toshihiro Okamoto
Summary: The operational stability of organic thin-film transistors (OTFTs) is crucial, and by replacing phenyl with perfluorophenyl groups, especially bias stress stability can be greatly enhanced in n-channel single-crystal OTFTs.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Ichiro Tanabe, Iroha Imoto, Daijiro Okaue, Masaya Imai, Shohei Kumagai, Tatsuyuki Makita, Masato Mitani, Toshihiro Okamoto, Jun Takeya, Ken-ichi Fukui
Summary: This study introduces a novel spectroscopic setup (EC-ATR-UV) to investigate the spectral properties of ionic liquid/organic films interfaces under an electric field. By analyzing the interfacial area, the researchers were able to correlate the spectral changes of organic semiconductors with gate voltage application and IL species, providing insights for electrochemical device development. Additionally, the study detected Stark shifts in both the organic semiconductor and IL on the organic semiconductor films, offering a new method that can be applied to other electrochemical devices such as organic thin film solar cells.
COMMUNICATIONS CHEMISTRY
(2021)
Review
Chemistry, Multidisciplinary
Shohei Kumagai, Hiroyuki Ishii, Go Watanabe, Craig P. Yu, Shun Watanabe, Jun Takeya, Toshihiro Okamoto
Summary: Organic semiconductors (OSCs) have potential applications in flexible and printed electronic devices, but the practical use of Organic thin-film transistors (OTFTs) is limited by lower carrier mobilities. N-type OSCs lag behind p-type OSCs in carrier mobility due to difficulties in achieving compatibility between aggregated structures and electron affinity. Rational molecular design principles are still needed for high-end device applications.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Tadanori Kurosawa, Toshihiro Okamoto, Yu Yamashita, Shohei Kumagai, Shun Watanabe, Jun Takeya
Summary: This study demonstrates a new strong and atmospherically stable p-dopant for semiconducting polymers, TAB-2TFSI, which can achieve high electrical conductivity and enhanced crystallinity. The concept of utilizing charged molecules as dopants is highly versatile and may accelerate the development of strong and stable dopants.
Article
Chemistry, Multidisciplinary
Craig P. Yu, Naoya Kojima, Shohei Kumagai, Tadanori Kurosawa, Hiroyuki Ishii, Go Watanabe, Jun Takeya, Toshihiro Okamoto
Summary: By synthesizing BQQDI derivatives with different substituents, the researchers demonstrated distinct molecular assemblies and charge-transport capabilities for these two organic semiconductors.
COMMUNICATIONS CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Shohei Kumagai, Takeru Koguma, Tatsuro Annaka, Chizuru Sawabe, Yukio Tani, Hiroki Sugiura, Tetsuya Watanabe, Daisuke Hashizume, Jun Takeya, Toshihiro Okamoto
Summary: Functionalization of pi-conjugated compounds is an important strategy for developing high-performance organic optoelectronic materials. In this study, the regioselective dibromination of a nitrogen-embedded perylene diimide analogue was achieved through palladium(II)-catalyzed oxidation and dicyanation. The resulting compound exhibited a deep lowest-unoccupied molecular orbital and good redox stability, leading to high electron mobility in transistors.
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
(2022)
Article
Chemistry, Physical
Tsubasa Mikie, Kenta Okamoto, Yuka Iwasaki, Tomoyuki Koganezawa, Masatomo Sumiya, Toshihiro Okamoto, Itaru Osaka
Summary: This study developed and synthesized a novel acceptor unit for conjugated polymers. The resulting polymer showed significantly improved electron and hole mobilities compared to its predecessor, likely due to the highly coplanar and rigid backbone. Furthermore, the incorporation of fluorine atoms as conformation-directing groups resulted in higher solubility and regular backbone structure for the polymer.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Craig P. Yu, Shohei Kumagai, Tomokatsu Kushida, Masato Mitani, Chikahiko Mitsui, Hiroyuki Ishii, Jun Takeya, Toshihiro Okamoto
Summary: This study demonstrates the influence of occupied molecular orbitals on charge transport in high-performance organic semiconductors. A novel molecular design is introduced to induce more pronounced mixed-orbital charge transport, leading to a high hole mobility.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Nanoscience & Nanotechnology
Masato Mitani, Shohei Kumagai, Craig P. Yu, Ayako Oi, Masakazu Yamagishi, Shuhei Nishinaga, Hiroki Mori, Yasushi Nishihara, Daisuke Hashizume, Tadanori Kurosawa, Hiroyuki Ishii, Nobuhiko Kobayashi, Jun Takeya, Toshihiro Okamoto
Summary: This study reported a new zigzag-shaped sulfur-bridged pi-electron core and its derivative, investigated their molecular design strategy and their impact on organic semiconductor performance through single-crystal structural analysis and band calculation.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Craig P. Yu, Akito Yamamoto, Shohei Kumagai, Jun Takeya, Toshihiro Okamoto
Summary: In this work, a benzo[de]isoquinolino[1,8-gh]quinoline diamide (BQQDA) pi-electron system was reported. The use of an electron-rich condensed amide instead of the usually employed imide provided suitable electronic features for chemical versatility in tailoring the BQQDA pi-electron system. Chemical modifications allowed for selective functionalization of the bay positions of the pi-skeleton. Furthermore, thionation of BQQDA was achieved under mild conditions. The resulting cyanated BQQDA organic semiconductor exhibited a high air-stable electron-carrier mobility.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Peter A. A. Banks, Gabriele D'Avino, Guillaume Schweicher, Jeff Armstrong, Christian Ruzie, Jong Won Chung, Jeong-Il Park, Chizuru Sawabe, Toshihiro Okamoto, Jun Takeya, Henning Sirringhaus, Michael T. T. Ruggiero
Summary: A study demonstrates the mechanism of electron-phonon coupling and the impact of molecular design on organic semiconductor materials. It reveals the effects of less commonly studied molecular vibrations and provides insights for creating improved materials.
ADVANCED FUNCTIONAL MATERIALS
(2023)
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)
Article
Chemistry, Multidisciplinary
Ryoto Yura, Shohei Kumagai, Kiyohiro Adachi, Daisuke Hashizume, Toshihiro Okamoto, Yoshiyuki Nonoguchi
Summary: This study demonstrates that supramolecular salt-functionalized n-doped ladder-type conducting polymers exhibit excellent stability in the presence of dry air.
CHEMICAL COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Yu Yamashita, Junto Tsurumi, Tadanori Kurosawa, Kan Ueji, Yukina Tsuneda, Shinya Kohno, Hideto Kempe, Shohei Kumagai, Toshihiro Okamoto, Jun Takeya, Shun Watanabe
Summary: Molecular doping of pi-conjugated semiconducting polymers can increase charge carrier density by forming intercalated compounds composed of layered polymers and guest intercalants. The multi-layer stacked nature of semicrystalline polymers allows the inclusion of various functional molecules. Intercalation cocrystal nature gives the best achievable doping level in semicrystalline polymers and excellent environmental stability.
COMMUNICATIONS MATERIALS
(2021)