Article
Biophysics
Sanghoon Baek, Hiroyuki Matsui, Taisei Mano, Ju An Park, Youngmin Jo, Yongwoo Lee, Shizuo Tokito, Jimin Kwon, Sungjune Jung
Summary: Organic thin-film transistors (TFTs) with an electrochemically functionalized sensing gate are promising platforms for wearable health-monitoring technologies. In this work, flexible printed dual-gate (DG) organic TFTs operating in the subthreshold regime are presented, achieving ultralow power and high sensitivity. An enzymatic lactate-sensing extended-gate electrode is integrated into the printed DG TFT, showing exceptional sensitivity (0.77) and ultralow static power consumption (10 nW) in physiological lactate monitoring with human saliva.
BIOSENSORS & BIOELECTRONICS
(2023)
Article
Chemistry, Multidisciplinary
Alina S. Sharova, Mario Caironi
Summary: Edible electronics, utilizing edible materials in electronic devices, proposes the use of honey as an electrolytic gate viscous dielectric in electrolyte-gated organic field-effect transistors (OFETs) to achieve low voltage operation and integrated logic circuits.
ADVANCED MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Wei-Cheng Kang, Jheng-Ying Wu, Yu-Tzu Cheng, Yu-Fu Wang, Yu-Jung Liao, Tzu-Hsuan Chang
Summary: The study introduces a new double-cell-height design that effectively reduces routing congestion and increased routing complexity of CFET, thus decreasing the RC delay of NAND cell family and lowering the output capacitance.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Chengji Jin, Jiacheng Xu, Jiani Gu, Jiayi Zhao, Xiaole Jia, Jiajia Chen, Huan Liu, Miaomiao Zhang, Yue Peng, Bing Chen, Ran Cheng, Yan Liu, Xiao Yu, Genquan Han
Summary: We experimentally investigated the disturb-free operations of multilevel cell (MLC) ferroelectric field-effect transistors (FeFETs) in a NAND array. We characterized the fabricated FeFET cells and investigated optimized schemes for stable writing of FeFET cells into multiple states. We proposed write and read schemes to achieve stable MLC operations of FeFET NAND arrays. This work provides a fundamental understanding of disturb-free MLC FeFET operations for NAND applications.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Review
Engineering, Electrical & Electronic
Hongquan Chen, Dan Luo, Qianqian Li, Xin Ma, Hao Liu, Liyan Liu
Summary: With the development of the Internet of Things era, smart wearable devices have become increasingly integrated into people's daily lives, bringing great convenience in real-time health monitoring and information transmission. This article explores the recent progress in organic thin-film transistor (OTFT) based on 2-D film and 1-D fiber, focusing on preparation methods and performance. Practical applications of OTFT sensors for human health detection are also introduced.
IEEE SENSORS JOURNAL
(2023)
Article
Nanoscience & Nanotechnology
Chi-Yuan Yang, Deyu Tu, Tero-Petri Ruoko, Jennifer Y. Gerasimov, Han-Yan Wu, Padinhare Cholakkal Harikesh, Matteo Massetti, Marc-Antoine Stoeckel, Renee Kroon, Christian Muller, Magnus Berggren, Simone Fabiano
Summary: The article discusses the development of low-power, high-gain flexible circuits based on printed complementary OECTs, which leverage the low threshold voltage of OECTs to detect voltage signals as low as 100 μV with high gain. These complementary voltage amplifiers demonstrate high performance in amplifying low-amplitude signals, setting a new standard in power-efficient platforms for sensing and amplifying voltage signals in emerging beyond-silicon applications.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Ranajoy Bhattacharya, Jin-Woo Han, Jim Browning, M. Meyyappan
Summary: A new complementary vacuum field emission device structure is proposed in this study, where a freely moving double-clamped cantilever is used as the source electrode with electron-emitting cathode formed on the source for n-type device and on the drain for p-type device. Multiphysics simulation shows that complementary current-voltage characteristics are obtained only with Fowler-Nordheim tunneling electron transport.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Juhyung Seo, Seongjae Kim, Hocheon Yoo
Summary: Logic-in-memory (LIM) technology is an important innovation that overcomes the limitations of the von Neumann architecture. To address issues related to high power consumption and low noise margin, researchers have developed a complementary LIM device with a stable noise margin. The proposed circuit uses a combination of p-type floating-gate transistor memory (FGTM) and n-type zinc-tin oxide (ZTO) thin-film transistor (TFT) to determine the output based on the state of the FGTM memory.
IEEE ELECTRON DEVICE LETTERS
(2022)
Review
Chemistry, Multidisciplinary
Xin Wang, Yixin Ran, Xiaoqian Li, Xinsu Qin, Wanlong Lu, Yuanwei Zhu, Guanghao Lu
Summary: This paper comprehensively discusses the investigation of transistor-based artificial synapses in bioinspired information processing, which are stable building blocks for brain-like computing. However, the influence of the semiconductor and device structural design on synaptic properties is still poorly understood. The recent advances in novel structure design of semiconductor materials and devices used in synaptic transistors are emphasized, along with the discussion and prediction of crises and opportunities in transistor-based synaptic interconnection.
MATERIALS HORIZONS
(2023)
Article
Engineering, Electrical & Electronic
Woojo Kim, Sungjune Jung
Summary: In this article, a three-dimensional (3-D) and printed static random-access memory (SRAM) based on complementary organic thin-film transistors is demonstrated. This high-performance SRAM showed the smallest area, highest normalized static noise margin, and maximum gain compared to reported values. The 3-D integration of transistors and cell design improvements enable potential applications in wearable electronics for data storage and processing.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Hsin Tseng, Anton Weissbach, Juzef Kucinski, Ali Solgi, Rakesh Nair, Lukas M. Bongartz, Giuseppe Ciccone, Matteo Cucchi, Karl Leo, Hans Kleemann
Summary: This study demonstrates the use of PEDOT:PSS-based dual-gate OECTs with solid-state electrolyte to seamlessly adjust the threshold voltage during operation. The ability to control the threshold voltage is of great technological importance and provides circuit designers with a simple and direct adjustment method.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Engineering, Electrical & Electronic
Koki Taguchi, Takafumi Uemura, Andreas Petritz, Naoko Namba, Mihoko Akiyama, Masahiro Sugiyama, Teppei Araki, Barbara Stadlober, Tsuyoshi Sekitani
Summary: Flexible electronics has opened up possibilities for the development of next-generation wearable and implantable healthcare devices. This study focuses on using a photoreactive insulating polymer to modulate the power consumption and operating speed of ultraflexible organic circuits. The results demonstrate that a nanoscale interfacial photochemical reaction can enable low power consumption and tunable operating speed in organic signal processing circuits.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Lorenzo Travaglini, Adam P. Micolich, Claudio Cazorla, Erica Zeglio, Antonio Lauto, Damia Mawad
Summary: The organic electrochemical transistor (OECT) with a conjugated polymer as the active material serves as the elementary unit of organic bioelectronic devices. By utilizing a complementary circuit with PANI as the channel material in both transistors, low power consumption and excellent performance can be achieved. This PANI-based circuit demonstrates a gain of approximately 7 and operates effectively in aqueous electrolyte on a flexible biocompatible chitosan substrate.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Zhaohan Peng, Fengjing Liu, Huijuan Sun, Yanjie Wang, Jiawei Wang, Chao Jiang
Summary: This study reports the fabrication of organic-inorganic heterojunction ambipolar transistors on flexible PI substrate and their application in logic circuits. The fabricated ambipolar transistors show V shape transfer characteristic curves and can realize a complementary-like inverter with dual operation quadrants. This work demonstrates the potential of processing heterojunction ambipolar transistors on flexible substrates for flexible electronics devices.
IEEE JOURNAL OF THE ELECTRON DEVICES SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Roberto Granelli, Ivano Alessandri, Paschalis Gkoupidenis, Irene Vassalini, Zsolt M. Kovacs-Vajna, Paul W. M. Blom, Fabrizio Torricelli
Summary: This study proposes fully printed mask-less OECTs fabricated on thin-film biodegradable and compostable substrates, enabling monolithic integration of high-performance bioelectronics.
Article
Physics, Applied
Shun Takahashi, Erika Kimura, Takeshi Ishida, Takeyoshi Tajiri, Katsuyuki Watanabe, Kenichi Yamashita, Satoshi Iwamoto, Yasuhiko Arakawa
Summary: We developed a micro-manipulation technique under optical microscope observation for accurate fabrication of three-dimensional photonic crystals (3D PhCs) in near-infrared light. By using the van der Waals force and precisely fabricated vertical posts, we achieved a stacking error that was an order of magnitude smaller than the period of the 3D PhCs. Photoluminescence measurement of a 3D PhC nanocavity containing quantum dots showed a cavity-mode peak in the near-infrared region.
APPLIED PHYSICS EXPRESS
(2022)
Article
Engineering, Electrical & Electronic
Renchun Tao, Tai Li, Jiajia Yang, Yixin Wang, Fang Liu, Bowen Sheng, Zhen Huang, Susu Yang, Liuyun Yang, Xin Rong, Tao Wang, Bo Shen, Yasuhiko Arakawa, Xinqiang Wang
Summary: In this study, the linewidth enhancement factor (LEF) of III-nitride quantum dot (QD) lasers was investigated using a comprehensive theoretical model. It was found that the LEF values of InGaN QD lasers can be smaller and more robust against inhomogeneous broadening than those of InGaAs QD lasers. Additionally, the improvement in LEF from quantum well to QD in III-nitride semiconductors is greater than that in III-arsenide. These findings not only highlight the advantages of III-nitride QD lasers for high spectral purity and low-chirp applications, but also provide a general guideline for designing QD lasers with lower LEF values in various semiconductor materials.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
Article
Nanoscience & Nanotechnology
Yoshiaki Hattori, Takashi Taniguchi, Kenji Watanabe, Masatoshi Kitamura
Summary: In this study, a metallic-Au layer was used to visualize ultra-thin hexagonal boron nitride (h-BN) films. Optical microscopy was used to observe and determine the number of layers in the h-BN films based on contrast. The results confirmed that the ultra-thin Au layer served as an electrode, and the tunneling current through the h-BN films matched the estimated number of layers from the contrast.
Correction
Optics
Jinkwan Kwoen, Takaya Imoto, Yasuhiko Arakawa
Summary: This is an article presenting an erratum to correct inadvertent errors in a previous paper. The corrections made will not affect the main conclusion.
Article
Nanoscience & Nanotechnology
Natsuko Ishida, Yasutomo Ota, Wenbo Lin, Tim Byrnes, Yasuhiko Arakawa, Satoshi Iwamoto
Summary: In this paper, a theoretical analysis of a large-scale single-mode laser based on a topological edge state is presented. The results demonstrate that stronger couplings between the cavities and lower losses are advantageous for achieving stable operation of the device. The laser also shows robustness under non-ideal situations.
Article
Physics, Applied
Yoshiaki Hattori, Takashi Taniguchi, Kenji Watanabe, Masatoshi Kitamura
Summary: This study proposes a visualization technique for identifying exfoliated monolayer hexagonal boron nitride flakes. By using a specific thickness of SiN x film, the contrast is enhanced compared to other films.
APPLIED PHYSICS EXPRESS
(2022)
Article
Optics
Kazuhiro Kuruma, Hironobu Yoshimi, Yasutomo Ota, Ryota Katsumi, Masahiro Kakuda, Yasuhiko Arakawa, Satoshi Iwamoto
Summary: This study reports single-photon sources using single quantum dots embedded in topological slow light waveguides based on valley photonic crystals. The experiment demonstrates Purcell-enhanced single-photon emission in a topological slow light mode with a group index over 20, showing robust propagation even under sharp bends.
LASER & PHOTONICS REVIEWS
(2022)
Article
Crystallography
Jinkwan Kwoen, Yasuhiko Arakawa
Summary: Reflection high-energy electron diffraction (RHEED) is a widely used technique for in-situ observations of sample surface behavior during molecular beam epitaxy (MBE) growth. However, the reliance on operator expertise and time limitations make it difficult to apply RHEED pattern analysis for real-time feedback control. In this study, a classification model capable of categorizing three or more classes is reported, suggesting the potential for a generalized RHEED pattern classifier.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Physics, Applied
Ryota Katsumi, Yasutomo Ota, Takeyoshi Tajiri, Satoshi Iwamoto, Kaur Ranbir, Johann Peter Reithmaier, Mohamed Benyoucef, Yasuhiko Arakawa
Summary: We present the hybrid integration of an InAs/InP quantum-dot (QD) single-photon source with a CMOS-processed Si photonics chip using transfer printing. This integration technique enables the assembly of photonic components through a pick-and-place operation, allowing for their introduction onto Si photonics chips after completing the entire CMOS-compatible fabrication processes. We demonstrate the generation of telecom single photons using an InAs/InP QD integrated on Si and their coupling into a waveguide. We also showcase the integration of a QD on a fiber-pigtailed Si chip and the single-photon output through the optical fiber, presenting a new pathway for modularizing solid-state quantum light sources.
APPLIED PHYSICS EXPRESS
(2023)
Article
Physics, Applied
Seung Hyuk Lee, Keisuke Kitano, Takahiro Doe, Noboru Iwata, Makoto Izumi, Yasuhiko Arakawa, Tetsu Tatsuma
Summary: The ligand engineering of quantum dots is crucial for improving the performance of QD light-emitting diode displays. This study demonstrates that exchanging an organic ligand with an inorganic ligand can enhance stability and efficiency of QLED devices. The thinner ligand layer improves carrier injection efficiency, resulting in improved external quantum efficiency and device lifetime.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Yoshiaki Hattori, Masatoshi Kitamura
Summary: The surface oxidation and reduction of Au thin films were investigated using X-ray photoelectron spectroscopy, work function measurements, and optical reflectance spectroscopy. Formation of AuOx on top of the Au film slightly shifted the wavelength of minimum reflectance. AuOx regions and non-oxidized Au regions were formed on the sample surface, and the contrast of the AuOx region gradually decreased over time.
Article
Materials Science, Multidisciplinary
Sonoka Yamamoto, Ryutaro Yamashita, Chihiro Kubota, Kentaro Okano, Masatoshi Kitamura, Masahiro Funahashi, Syu-Cheng Ye, Yung-Tin Pan, Masaki Horie, Takuji Shintani, Hironori Murata, Hideto Matsuyama, Atsunori Mori
Summary: A thiophene-thiophene block copolymer with hydrophilic and hydrophobic side chains was synthesized. The block copolymer exhibited cylindrical microphase separation and the hydrophilic domain penetrated perpendicular to the substrate. The conductive properties of the thin film changed depending on its orientation to the substrate, with parallel orientation being conductive and perpendicular orientation being insulative. Electrochemical analysis showed that lithium ions transferred through the cylindrical domain composed of benzene sulfonic acid side chains.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Nanoscience & Nanotechnology
Yoshiaki Hattori, Takashi Taniguchi, Kenji Watanabe, Masatoshi Kitamura
Summary: This study investigated the visualization of thick hBN and graphite flakes on SiO2/Si substrates through calculations and experiments. The experimental results showed that flakes with different thicknesses exhibited different brightness in optical microscope images. Additionally, the observation using differential interference contrast (DIC) microscopy revealed differences in brightness and colors for flakes with different thicknesses.
Article
Engineering, Electrical & Electronic
Yoshiho Maeda, Takuma Aihara, Takuro Fujii, Tatsurou Hiraki, Koji Takeda, Tai Tsuchizawa, Hiroki Sugiyama, Tomonari Sato, Toru Segawa, Yasutomo Ota, Satoshi Iwamoto, Yasuhiko Arakawa, Shinji Matsuo
Summary: In this study, we developed directly modulated membrane distributed reflector (DR) lasers on a Si waveguide using micro-transfer printing method. Micro-transfer printing allows low-loss coupling and pre-integration testing. The membrane lasers with a lateral p-i-n diode structure possess low capacitance, high optical confinement factor, low threshold current, and high-speed modulation. The fabricated membrane DR laser integrated with a 220-nm-thick Si waveguide demonstrated low threshold current, single-mode operation, and high-speed signal modulation.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Shun Takahashi, Takeyoshi Tajiri, Yasuhiko Arakawa, Satoshi Iwamoto, Willem L. Vos
Summary: In this study, we investigate the optical properties of direct and inverse three-dimensional chiral woodpile structures and a corresponding chiral Bragg stack. We compute transmission spectra in the helical direction and observe dual-band circular dichroism. The appearance of circularly polarized gaps can be explained by a physical model involving the corotation or counterrotation of circular polarization with the chiral structure, leading to a spatially dependent or constant refractive index.
