Review
Chemistry, Multidisciplinary
Jiajun Song, Hong Liu, Zeyu Zhao, Peng Lin, Feng Yan
Summary: Flexible and stretchable biosensors are increasingly utilized for acquiring high-fidelity signals in emerging applications. Organic thin film transistors (OTFTs) are ideal candidates for flexible and stretchable biosensing due to their soft nature, amplification function, biocompatibility, functionalization ease, low cost, and device diversity. This review provides a comprehensive overview of the advancements in flexible-OTFT-based biosensors, discussing their features, functionalization strategies, applications in wearable, implantable, and portable electronics, as well as neuromorphic biointerfaces. Special attention is given to emerging stretchable organic transistors and their engineering routes for achieving stretchability, along with their implementations in e-skin and smart textiles. The remaining challenges and future opportunities in this field are also summarized.
ADVANCED MATERIALS
(2023)
Review
Chemistry, Multidisciplinary
Yao Yao, Wei Huang, Jianhua Chen, Xiaoxue Liu, Libing Bai, Wei Chen, Yuhua Cheng, Jianfeng Ping, Tobin J. Marks, Antonio Facchetti
Summary: Flexible and stretchable bioelectronics, such as organic electrochemical transistors (OECTs), have received significant attention for in situ monitoring of biological systems. These devices exhibit advantages in biological sensing due to their ionic switching behavior, low driving voltage, and high transconductance. Recent research has focused on developing flexible/stretchable OECTs (FSOECTs) for biochemical and bioelectrical sensors, and this review summarizes the major accomplishments and challenges in this field.
ADVANCED MATERIALS
(2023)
Review
Chemistry, Multidisciplinary
Ali Nawaz, Leandro Merces, Leticia M. M. Ferro, Prashant Sonar, Carlos C. B. Bufon
Summary: The development of flexible and conformable devices is a significant step towards the realization of next-generation wearable and e-textile applications. Organic field-effect transistors (OFETs), specifically planar and vertical OFETs (POFETs and VOFETs), are particularly interesting due to their low-temperature solution processability, mechanical flexibility, and compatibility with plastic and biodegradable substrates. This in-depth review critically discusses the electrical, mechanical, and physical properties of POFETs and VOFETs, with a focus on key applications such as integrated logic circuits, light-emitting devices, memories, and sensors.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jiankui Zhou, Hanfang Feng, Qingqing Sun, Zhengkun Xie, Xinchang Pang, Takeo Minari, Xuying Liu, Li Zhang
Summary: A representative closely packed conjugated polyrotaxane (CPR1) is synthesized by threading polyaniline (PAN) into beta-cyclodextrin (CD) macrocycles and utilized to construct an RRAM device with outstanding resistive switching capability. The CPR1 RRAM device shows remarkable nonvolatile memory performance, ultra-fast response time, excellent reliability and stability. This work demonstrates the potential of CPR materials in highly stable memory devices for next-generation flexible and wearable electronics.
MATERIALS HORIZONS
(2022)
Article
Chemistry, Physical
Ke Pei
Summary: In this work, a two-dimensional CuInP2S6 crystal is integrated into Fe-OFETs, which exhibit excellent ferroelectric performance and high programming speed. The flexible devices also show promising performance for short-term data storage and integration with other flexible electronics.
SURFACES AND INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Ping Ren, Runqiao Song, Yong Zhu, Brendan O'Connor, Jingyan Dong
Summary: The demand for cost-effective fabrication of printed flexible transistors has increased due to the need for flexible interface devices like e-skins, wearables, and medical patches. This study develops electrohydrodynamic printing processes to fabricate all components of polymer-based organic thin film transistors, streamlining the fabrication procedure. The fully EHD-printed OTFTs show good electrical performance and great mechanical flexibility, providing a cost-effective route for flexible electronics.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Review
Nanoscience & Nanotechnology
S. M. Sattari-Esfahlan, Chang-Hyun Kim
Summary: With the increasing importance of memory technologies in our ever-digitalizing society, graphene is emerging as a promising material for building high-performance memories. There is a need to address some remaining issues for the advancement of flexible graphene memories in the future.
ACS APPLIED NANO MATERIALS
(2021)
Review
Chemistry, Physical
Fuming Wu, Yixuan Liu, Jun Zhang, Shuming Duan, Deyang Ji, Hui Yang
Summary: This review summarizes the recent advances in research on stretchable organic field-effect transistors (OFETs) with high mobility, including core materials, self-healing mechanisms, different configurations, potential applications, as well as future research directions and challenges.
Review
Chemistry, Multidisciplinary
Haoran Liu, Dong Liu, Junchuan Yang, Hanfei Gao, Yuchen Wu
Summary: Organic flexible electronic devices with outstanding properties, such as solution processability, lightweight, and flexibility, have the potential to revolutionize lifestyles. The precise patterning and ordered assembly of organic semiconductors for integration in flexible electronics have attracted attention and rapidly developed. This review focuses on recent advances in the design, patterned assembly, and multifunctional applications of flexible organic field-effect transistors (FOFETs). It introduces typical organic semiconductor materials and material design methods, discusses patterned assembly strategies on flexible substrates, and highlights advanced applications of flexible electronic devices based on organic semiconductor patterns. Future challenges and possible directions for the development of the next generation of flexible electronics are also proposed.
Review
Nanoscience & Nanotechnology
Yunchao Xu, Wanrong Liu, Yulong Huang, Chenxing Jin, Bosheng Zhou, Jia Sun, Junliang Yang
Summary: Flexible organic synaptic transistors have gained significant attention recently due to their flexibility, biocompatibility, and low energy consumption in mimicking neuromorphic functions. These devices show promising applications in electronic skin, artificial vision system, human brain interface, and wearable consumer electronics.
ADVANCED ELECTRONIC MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Omid Dadras-Toussi, Milad Khorrami, Anto Sam Crosslee Louis Sam Titus, Sheereen Majd, Chandra Mohan, Mohammad Reza Abidian
Summary: By incorporating organic semiconductor materials and utilizing multiphoton lithography technology, three-dimensional OS composite microstructures with high electrical conductivity and biocompatibility were successfully fabricated, providing an efficient platform for sensitive glucose detection in biosensors.
ADVANCED 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
Materials Science, Multidisciplinary
Peter Andersson Ersman, Roman Lassnig, Jan Strandberg, Peter Dyreklev
Summary: A flexible, electrochromic, active matrix addressed display (AMAD) is demonstrated, manufactured on a plastic substrate solely using screen printing. Each organic electrochromic smart pixel (OESP) is a combination of an organic electrochromic display (OECD) and an organic electrochemical transistor (OECT), printed in multilayered vertical architectures. The conduction state of the OECT enables control of the color state of its corresponding OECD, while electrical wires connecting each component are formed by screen printing with silver or nanocopper-based ink.
ADVANCED ENGINEERING MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Sachin Rahi, Vivek Raghuwanshi, Gargi Konwar, Shree Prakash Tiwari
Summary: In this study, a high-performance flexible solution-processed nonvolatile memory based on organic field-effect transistor (OFET-NVM) was presented. The flexible OFET-NVMs with P(VDF-TrFE) as a gate dielectric exhibited excellent memory behavior, with a high memory window of 12 V for V-GS sweep and a stable retention capability for higher than 10(4) s. The devices also showed reliable NVM behavior even after 100 repeated bending cycles, making them promising candidates for flexible electronics exploration.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Physics, Applied
Sabeen Fatima, Rabia Tahir, Syed Rizwan
Summary: This study presents a novel MXene flexible memory device with substrate-free growth in ambient conditions, which has attracted interest in current innovation due to its high nonvolatile storage, light weight, smart, portable, and better functioned memories. The synthesis of MXene sheets was confirmed through surface morphology, elemental and structural analysis. X-ray diffraction, Raman, and FTIR spectra showed the presence of TiO2 inside FE-Ti3C2Tx MXene, which contributed toward the ferroelectric behavior of MXene.
APPLIED PHYSICS LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Youngjun Park, Jang-Sik Lee
Summary: Organic-inorganic halide perovskites (OIHPs), especially stable two-dimensional Dion-Jacobson OIHPs, have shown great potential in resistive switching memory (RSM). The grain sizes of OIHP can be effectively controlled to modulate the paths for ion migration, thus changing the on/off ratio of RSM. In high-density memory applications, selector devices are necessary to suppress leakage current from neighboring cells. These findings highlight the potential of OIHP for use in high-density memory applications.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Dongshin Kim, Jang-Sik Lee
Summary: Neurotransmitters play a crucial role in controlling signal transmission in the nervous system, and the balance between excitatory and inhibitory synaptic responses is fundamental for the characteristics of the nervous system. This study develops artificial synapses that emulate the excitatory and inhibitory functions of biological synapses, paving the way for bio-realistic neuromorphic devices.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Akshay Sahota, Harrison Sejoon Kim, Jaidah Mohan, Yong Chan Jung, Heber Hernandez-Arriaga, Dan N. Le, Si Joon Kim, Jang-Sik Lee, Jinho Ahn, Jiyoung Kim
Summary: In this study, a threshold switching (TS) selector with an Ag doping-based nano-polycrystalline ZnO switching layer was developed. The TS selector showed remarkable electroforming-free selection behavior, high device yield, and stable threshold voltage.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Eun-Kyeong Jang, Ik-Jyae Kim, Cheon An Lee, Chiweon Yoon, Jang-Sik Lee
Summary: This study simulated 3D NAND flash to investigate the influence of deposition temperatures on residual stress and electrical characteristics. The relationship between residual stress and electrical characteristics was described using the energy band shift. These findings have the potential to improve cell performances and optimize process parameters in 3D NAND flash technology.
IEEE JOURNAL OF THE ELECTRON DEVICES SOCIETY
(2022)
Article
Multidisciplinary Sciences
Min-Kyu Kim, Ik-Jyae Kim, Jang-Sik Lee
Summary: In this study, integrated ferroelectric thin-film transistor (FeTFT) synaptic arrays were demonstrated to provide efficient parallel programming and data processing for CNNs through selective and accurate control of polarization in the ferroelectric layer.
Article
Physics, Applied
Ik-Jyae Kim, Min-Kyu Kim, Jang-Sik Lee
Summary: This study demonstrates the scalability of Hafnia-based ferroelectric thin-film transistors (FeTFTs) to a 10-nm dimension and showcases their high scalability and suitability for ultrahigh-density memory applications.
APPLIED PHYSICS LETTERS
(2022)
Review
Chemistry, Multidisciplinary
Ik-Jyae Kim, Jang-Sik Lee
Summary: This review summarizes the recent developments in ferroelectric devices, particularly ferroelectric transistors, for next-generation memory and neuromorphic applications. It first reviews the types and operation mechanisms of ferroelectric memories, then discusses the issues limiting the realization of high-performance ferroelectric transistors and possible solutions. It also reviews the experimental demonstration of ferroelectric transistor arrays, including 3D ferroelectric NAND and its operation characteristics, and outlines the challenges and strategies towards the development of next-generation memory and neuromorphic applications based on ferroelectric transistors.
ADVANCED MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Ik-Jyae Kim, Min-Kyu Kim, Jang-Sik Lee
Summary: Oxide semiconductors are promising channel materials for hafnia-based ferroelectric transistor memories. A novel design strategy is proposed to achieve increased polarization switching in oxide semiconductor-based thin-film transistors. By inserting an additional p-type CuOx layer, increased polarization switching is achieved. The results demonstrate a novel structure and fabrication method for high-performance FeTFTs for advanced 3D non-volatile memory applications.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Multidisciplinary Sciences
Ik-Jyae Kim, Min-Kyu Kim, Jang-Sik Lee
Summary: Hardware-based neural networks (NNs) have the potential to revolutionize AI applications by extracting features from unstructured data and learning from them. However, implementing complex NN models is challenging because different tasks require different memory elements and arrays, resulting in increased chip size.
NATURE COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Goutam Kumar Gupta, Ik-Jyae Kim, Youngjun Park, Min-Kyu Kim, Jang-Sik Lee
Summary: This study demonstrates a photonic multimodal synaptic device with favorable band alignment that enables optically induced charge trapping and nonvolatile memory characteristics. The device exhibits high photoresponse and excellent synaptic characteristics through gate voltage regulation. It also shows multiwavelength response and a large dynamic range suitable for accurate artificial neural network. The simulation results based on experimental data show excellent pattern recognition accuracy after 120 epochs, demonstrating the feasibility of the device as an optical synapse in the next-generation neuromorphic system.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Min-Kyu Kim, Ik-Jyae Kim, Jang-Sik Lee
Summary: Zirconium-doped hafnium oxide (HfZrOx) films were studied to investigate the effects of ozone exposure time during the atomic layer deposition (ALD) process on their polarization and endurance characteristics. It was found that HfZrOx with an ozone exposure time of 2.5 s exhibited the most stable endurance characteristics due to its low initial defect concentration, which was confirmed by leakage current analysis. This study highlights the importance of controlling the ozone exposure time in ALD to optimize the formation of defects in HfZrOx films for improved polarization and endurance characteristics.
Article
Engineering, Electrical & Electronic
Dongshin Kim, Jang-Sik Lee
Summary: Liquid-based devices have gained attention as bioinspired neuromorphic applications due to their advantageous properties, including high ion-diffusion coefficients and controllable ion-exchange reactions. By engineering liquid materials, multifunctional computing devices have been developed for memory and neuromorphic purposes, emulating synaptic plasticity, homeostasis, and action potentials. Utilizing liquids in computing devices offers a promising platform for high-performance memory devices and enables bioinspired computing functions.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Review
Chemistry, Multidisciplinary
Min-Kyu Song, Ji-Hoon Kang, Xinyuan Zhang, Wonjae Ji, Alon Ascoli, Ioannis Messaris, Ahmet Samil Demirkol, Bowei Dong, Samarth Aggarwal, Weier Wan, Seok-Man Hong, Suma George Cardwell, Irem Boybat, Jae-sun Seo, Jang-Sik Lee, Mario Lanza, Hanwool Yeon, Murat Onen, Ju Li, Bilge Yildiz, Jesus A. del Alamo, Seyoung Kim, Shinhyun Choi, Gianluca Milano, Carlo Ricciardi, Lambert Alff, Yang Chai, Zhongrui Wang, Harish Bhaskaran, Mark C. Hersam, Dmitri Strukov, H. -S. Philip Wong, Ilia Valov, Bin Gao, Huaqiang Wu, Ronald Tetzlaff, Abu Sebastian, Wei Lu, Leon Chua, J. Joshua Yang, Jeehwan Kim
Summary: Memristive technology, with oxide-based resistive switches as memristors, has gained significant attention due to its biomimetic memory properties and potential improvement in power consumption. This review provides a comprehensive overview of recent advances in memristive technology, including devices, theory, algorithms, architectures, and systems. It also discusses research directions for applications in AI hardware accelerators, in-sensor computing, and probabilistic computing. Furthermore, it offers a forward-looking perspective, outlining challenges and opportunities for further research and innovation in this field.
Article
Engineering, Electrical & Electronic
Ik-Jyae Kim, Jang-Sik Lee
Summary: This study presents a low-thermal-budget transparent ferroelectric transistor with high transmittance and good switching performance, which is suitable for next-generation transparent display technologies.
IEEE ELECTRON DEVICE LETTERS
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Jang-Sik Lee
Summary: Recently, there has been active research on the fabrication and characterization of ferroelectric materials and devices for memory and neuromorphic device applications. This paper discusses the recent research activities on the fabrication of ferroelectric thin-film transistors (FeTFTs) in detail, aiming to develop high-density memory devices. Furthermore, FeTFTs demonstrate analog memory characteristics by controlling the polarization states of ferroelectric materials, making them suitable for neuromorphic device applications.
TWENTY-NINETH INTERNATIONAL WORKSHOP ON ACTIVE-MATRIX FLATPANEL DISPLAYS AND DEVICES: TFT TECHNOLOGIES AND FPD MATERIALS (AM-FPD 22)
(2022)