Article
Chemistry, Multidisciplinary
Qiuju Wu, Qing Yu, Gang He, Wenhao Wang, Jinyu Lu, Bo Yao, Shiyan Liu, Zebo Fang
Summary: This paper investigates the impact of atomic layer deposition (ALD)-derived Al2O3 passivation layers and annealing temperatures on the interfacial chemistry and transport properties of sputtering-deposited Er2O3 high-k gate dielectrics on Si substrate. X-ray photoelectron spectroscopy (XPS) analyses reveal that the ALD-derived Al2O3 passivation layer effectively prevents the formation of low-k hydroxides and optimizes the gate dielectric properties. Electrical performance measurements demonstrate that the Al2O3/Er2O3/Si MOS capacitor achieves the lowest leakage current density of 4.57 x 10(-9) A/cm(2) and the smallest interfacial density of states (Dit) of 2.38 x 10(12) cm(-2) eV(-1) due to the optimized interface chemistry. Furthermore, annealing the Al2O3/Er2O3/Si gate stacks at 450 degrees C improves the dielectric properties with a leakage current density of 1.38 x 10(-9) A/cm(2), and different conduction mechanisms of MOS devices under various stack structures are investigated systematically.
Article
Physics, Applied
Farzan Gity, Fintan Meaney, Anya Curran, Paul K. Hurley, Stephen Fahy, Ray Duffy, Lida Ansari
Summary: This paper presents comprehensive density functional theory-based simulations to understand the characteristics of dopant atoms in ultra-thin Si films. Results show that doping thinner films is more difficult, but surface doping is more favorable than core doping.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Carsten Strobel, Carlos A. Chavarin, Karola Richter, Martin Knaut, Johanna Reif, Sandra Voelkel, Andreas Jahn, Matthias Albert, Christian Wenger, Robert Kirchner, Johann W. Bartha, Thomas Mikolajick
Summary: A graphene-based three-terminal barristor device was proposed to overcome the low on/off ratios and insufficient current saturation of conventional graphene field-effect transistors. This device, called graphene adjustable-barriers transistor (GABT), utilizes a semiconductor-based gate to modulate the device currents and demonstrates high current gain. The functionality of a silicon-graphene-germanium GABT with ultra-high current gain was successfully demonstrated.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Carsten Strobel, Carlos A. Chavarin, Karola Richter, Martin Knaut, Johanna Reif, Sandra Voelkel, Andreas Jahn, Matthias Albert, Christian Wenger, Robert Kirchner, Johann W. Bartha, Thomas Mikolajick
Summary: In this study, a novel graphene-based transistor called graphene adjustable-barriers transistor (GABT) was proposed and analyzed. It utilizes a semiconductor-based gate to modulate the device currents, overcoming the low on/off ratios and insufficient current saturation of conventional graphene transistors.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Siva Pratap Reddy Mallem, Peddathimula Puneetha, Yeojin Choi, Seung Mun Baek, Sung Jin An, Ki-Sik Im
Summary: Understanding the carrier transport mechanisms in nanowires is crucial for the creation of next-generation nanoscale devices. In this study, the effects of temperature on GaN nanowire wrap-gate transistors (WGTs) made via a top-down technique were examined. The predicted conductance in this transistor remains unchanged up to a temperature of 240 K and then increases as the temperature rises. Different behaviors were observed at different gate voltages, suggesting the presence of phonon and impurity scattering processes on the surface or core of GaN nanowires.
Article
Chemistry, Multidisciplinary
Kibret A. Messalea, Nitu Syed, Ali Zavabeti, Md Mohiuddin, Azmira Jannat, Patjaree Aukarasereenont, Chung K. Nguyen, Mei Xian Low, Sumeet Walia, Benedikt Haas, Christoph T. Koch, Nasir Mahmood, Khashayar Khoshmanesh, Kourosh Kalantar-Zadeh, Torben Daeneke
Summary: A stoichiometric cubic polymorph of 2D antimony oxide (Sb2O3) was synthesized as an ideal high-k dielectric sheet using a low-temperature, substrate-independent, silicon-industry-compatible liquid metal synthesis technique. The obtained alpha-Sb2O3 exhibited high crystallinity, wide band gap of approximately 4.4 eV, and a maximum relative permittivity of 84 with a breakdown electric field of around 10 MV/cm. The isolated 2D alpha-Sb2O3 nanosheets showed promise as gate oxides for conventional and van der Waals heterostructure-based electronics due to low leakage currents in top-gated field-effect transistors.
Article
Nanoscience & Nanotechnology
Yanfei Liu, Jianfeng Li, Jinjin Li, Shuang Yi, Xiangyu Ge, Xin Zhang, Jianbin Luo
Summary: A new lubrication system was designed to achieve macroscale superlubricity with a BP coating by depositing BP nanoflakes on the BP coating and using water lubrication. The superlubricity mechanism is mainly attributed to the shear-induced interfacial structural conversion of BP to phosphorus oxide, resulting in the formation of tribofilms with extremely low shear strength on the friction pairs.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Polymer Science
Ching-Lin Fan, Hou-Yen Tsao, Yu-Shien Shiah, Che-Wei Yao, Po-Wei Cheng
Summary: This study proposed using a high-K PVA/low-K PVP bilayer structure as the gate insulator to enhance a pentacene-based organic thin-film transistor. The bilayer gate dielectric with a dielectric constant of 5.6 resulted in increased gate capacitance and drain current. The device performances were significantly improved, with the field-effect mobility increasing from 0.16 to 1.12 cm(2)/(Vs), 7 times higher than that of the control sample.
Article
Materials Science, Multidisciplinary
Meshal Alzaid, Muhammad Zahir Iqbal, Syed Shabhi Haider, Sana Zakar, Sana Khan, C. Bilel, W. S. Mohamed, N. M. A. Hadia, Fai Alsalh
Summary: The study demonstrated the modulation of electrical properties of graphene devices by using honey as a top gate dielectric, leading to increased charge carrier mobility. The results suggest that natural dielectric materials can be a good candidate to replace conventionally available gate dielectrics in FET technology.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Kalyan Mondol, Mehedi Hasan, Abdul Hasib Siddique, Sharnali Islam
Summary: In this work, the effects of changing device parameters on n-type double gate silicon tunneling field effect transistor (TFET) are investigated. Multiple parameters are considered to evaluate the device's performance. It is found that short channel length, high gate dielectric material, and effective mass equal to or more than 0.04 mo show promising performance.
RESULTS IN PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Yunpeng Yan, Songang Peng, Zhi Jin, Dayong Zhang, Jingyuan Shi
Summary: Due to its susceptibility to external environmental factors, the graphene field-effect transistor (GFET) is affected by surface contamination from lithography residues. To address this issue, we developed an interface cleaning technology that is compatible with large-scale GFET production and the standard CMOS process. By fabricating the source/drain electrodes on the substrate before transferring the graphene film, we were able to avoid photoresist residues and achieve a cleaner interface, resulting in improved GFET performance.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yihui Zhou, Lingqiao Li, Zhihui He, Yixuan Wang, Wei Cui, Zhimin Yang, Shaojun Lu, Xiongxiong Wu, Lang Bai
Summary: A composite MXene/BP-based metasurface has been proposed for investigating the optical responses and electric field. The research findings show that Fano resonance-like spectra can be observed when the coupling of surface plasmons on the BP and MXene layers appears. Furthermore, field enhancement can be improved by adjusting the structural parameters and the polarization direction of incident light for the proposed metasurface.
Article
Physics, Applied
Cong Wang, Yurong Liu, Baozi Wu, Jian Sui
Summary: The study has used double-stacked gate dielectrics (DSGD) to enhance the electrical performance of zinc oxide thin-film transistors (ZnO-TFT) with single-layer NbLaO gate dielectric (SLGD). Compared to ZnO-TFT with SLGD, the ZnO-TFTs with DSGD have shown significant improvement in electrical performance, particularly for the device with NbLaO/SiO2 DSGD, with increased field-effect mobility, on/off current ratio and reduced subthreshold slope. The enhanced performance is attributed to low surface roughness and trap-state density in the bulk of the channel and at the ZnO/NbLaO interface. These findings suggest the potential application of ZnO-TFTs with DSGD in high-resolution flat panel displays.
MODERN PHYSICS LETTERS B
(2023)
Article
Energy & Fuels
Guoqing Wang, Zongmei Guo, Chen Chen, Weili Yu, Bo Xu, Bin Lin
Summary: In this study, a new type of BP/MoSe2 heterostructure thin film solar cell is proposed, which shows enhanced photoelectric characteristics and higher power conversion efficiency compared to BP/MoS2 heterostructure. The built-in electric field at the interface of BP/MoSe2 heterostructure accelerates the separation of electron-hole pairs. This research provides a feasible strategy for developing high-efficiency thin film solar cells.
Article
Materials Science, Multidisciplinary
Jiafei Yao, Xin Liu, Mingshun Sun, Tianci Xu, Man Li, Jing Chen, Maolin Zhang, Jun Zhang, Yufeng Guo
Summary: This paper investigates the double dielectrics enhancement LDMOS (DDE LDMOS) with high-k field dielectric and low-k buried dielectric. The analytical models of the potential and electric field, optimal breakdown voltage and drift doping concentration are established for this novel LDMOS. The validity of the analytical models is confirmed by the simulation results. Based on the analytical and simulated results, the modulation mechanism of the high-k field dielectric and low-k buried dielectric on the electric field and breakdown characteristics of DDE LDMOS are analyzed and compared. Compared to the conventional LDMOS, the specific on-resistance of DDE LDMOS is reduced by 19%, the breakdown voltage and figure of merit (FOM) of the DDE LDMOS can be improved by 62% and 222.4% when the permittivity of high-k field dielectric and low-k buried dielectric are 100 and 2. Meanwhile, the transfer characteristic, output characteristic, frequency characteristic, and switching characteristic of the DDE LDMOS are also discussed.
RESULTS IN PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Yesheng Li, Shuai Chen, Zhigen Yu, Sifan Li, Yao Xiong, Mer-Er Pam, Yong-Wei Zhang, Koh-Wee Ang
Summary: This paper presents a low-voltage memristor array based on an ultrathin PdSeOx/PdSe2 heterostructure switching medium, which solves the problem of random ion transport in traditional memristors, achieving remarkable uniform switching with low variability. Convolutional image processing with high recognition accuracy was also achieved by using various crossbar kernels.
ADVANCED MATERIALS
(2022)
Review
Green & Sustainable Science & Technology
Z. Y. Yeo, Z. P. Ling, J. W. Ho, Q. X. Lim, Y. H. So, S. Wang
Summary: This article discusses the stability issues of silicon-based solar cells under sunlight illumination and the research on improving performance through the use of alternative silicon materials and regeneration technologies. The results show that the performance of solar cells significantly improves after the regeneration process.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Nanoscience & Nanotechnology
Bochang Li, Wei Wei, Li Luo, Ming Gao, Zhi Gen Yu, Sifan Li, Kah-Wee Ang, Chunxiang Zhu
Summary: A novel electrochemical metallization memristor based on solution-processed Pt/CuI/Cu structure is proposed and demonstrated in this work. It has high resistance switching ratio and low power consumption, enabling Boolean logic operations and image encryption and decryption.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Energy & Fuels
Z. P. Ling, Q. X. Lim, K. N. Lim, J. W. Ho, S. Wang
Summary: This study compares the performance of solar modules comprised of p-PERC silicon solar cells that have undergone advanced hydrogenation treatment with those that have not. The results show that advanced hydrogenation technology effectively addresses the issues of light-induced degradation and light-and elevated-temperature induced degradation, resulting in higher power generation capability for the hydrogenated solar arrays.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2022)
Article
Multidisciplinary Sciences
Viacheslav Sorkin, Hangbo Zhou, Zhi Gen Yu, Kah-Wee Ang, Yong-Wei Zhang
Summary: In this study, the effects of different types, locations, and densities of point defects in monolayer MoS2 on the electronic structures and Schottky barrier heights (SBH) of Au/MoS2 heterojunction are investigated using DFT calculations. The results show that the SBH of monolayer MoS2 with defects is universally higher than that of the defect-free counterpart. Specifically, S divacancy and Mo-S antisite defects have a larger effect on increasing the SBH compared to S monovacancy. Defects located in the inner sublayer of MoS2 also have a larger impact on the SBH than those in the outer sublayer. Increasing defect density leads to a higher SBH. These findings provide practical guidelines for controlling and optimizing the SBH in Au/MoS2 heterojunctions through defect engineering.
SCIENTIFIC REPORTS
(2022)
Review
Chemistry, Multidisciplinary
Jun-young Kim, Xin Ju, Kah-Wee Ang, Dongzhi Chi
Summary: Two-dimensional materials have attracted attention for their potential in scientific breakthroughs and technological innovations. The integration of 2DMs on Si CMOS platform or flexible electronics has gained interest for applications such as back-end-of-line transistors, memory devices/ selectors, and sensors. The successful transfer of 2DM layers from growth substrate to Si is crucial for these applications, and various transfer methods leveraging van der Waals transfer capability have been developed. This review surveys and compares these transfer methods, focusing on 2D TMDC film transfer and 2DM template-assisted van der Waals growth/transfer of non-2D thin films.
Article
Chemistry, Multidisciplinary
Yu-Chieh Chien, Heng Xiang, Yufei Shi, Ngoc Thanh Duong, Sifan Li, Kah-Wee Ang
Summary: The study demonstrates a hafnium oxide-based ferroelectric encoder for temporal-efficient information processing in SNN. This high-performance ferroelectric encoder features superior switching efficiency and robust ferroelectric response, achieving a broad dynamic range.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Heng Xiang, Yu-Chieh Chien, Lingqi Li, Haofei Zheng, Sifan Li, Ngoc Thanh Duong, Yufei Shi, Kah-Wee Ang
Summary: This study demonstrates the capabilities of an integrated ferroelectric HfO2 and 2D MoS2 channel FeFET for achieving high-performance 4-bit per cell memory and low variation and power consumption synapses. The device retains the ability to implement diverse learning rules and accurately recognizes MNIST handwritten digits with over 94% accuracy using online training mode. These results highlight the potential of FeFET-based in-memory computing for future neuromorphic computing applications.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yu-Chieh Chien, Heng Xiang, Jianze Wang, Yufei Shi, Xuanyao Fong, Kah-Wee Ang
Summary: By harnessing the physically unclonable properties, true random number generators (TRNGs) can generate random bitstreams that are cryptographically secured, alleviating security concerns. However, conventional hardware often shows predictable patterns susceptible to machine learning attacks. This paper presents a low-power self-corrected TRNG based on molybdenum disulfide ferroelectric field-effect transistors, which exhibits enhanced stochastic variability and passes machine learning attacks, as well as statistical tests.
Article
Automation & Control Systems
Ngoc Thanh Duong, Yu-Chieh Chien, Heng Xiang, Sifan Li, Haofei Zheng, Yufei Shi, Kah-Wee Ang
Summary: A 1D array of Fe-FET based on alpha-In2Se3 channel is demonstrated, which exhibits volatile memory effect and is capable of implementing various RC systems. It achieves high accuracy in image classification and accurate forecasting of real-life chaotic systems such as weather.
ADVANCED INTELLIGENT SYSTEMS
(2023)
Article
Chemistry, Multidisciplinary
Zhengjin Weng, Haofei Zheng, Wei Lei, Helong Jiang, Kah-Wee Ang, Zhiwei Zhao
Summary: This study demonstrates the successful fabrication of high-yield, high-performance, and uniform memristors using a single-crystalline few-layered manganese phosphorus trisulfide (MnPS3) as a resistive switching medium. The memristors exhibit desired characteristics for neuromorphic computing and achieve a high accuracy of 95.15% in supervised learning using the MNIST handwritten recognition dataset. This research is significant for experimental studies on memristors.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Yangwu Wu, Ngoc Thanh Duong, Yu-Chieh Chien, Song Liu, Kah-Wee Ang
Summary: Neuromorphic computing, specifically reservoir computing (RC), is an effective approach for time-series analysis and forecasting in economics and engineering. In this study, a synapse device based on CuInP2S6 (CIPS) material is demonstrated, achieving synaptic performance emulation and temporal dynamics under electrical stimulation. The migration of Cu+ ions in CIPS is controlled, and the device exhibits low normalized root mean square errors (NRMSE) for various tasks, highlighting the potential of CIPS for real-time signal processing and expanding applications in neuromorphic computing.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Xinke Liu, Yuheng Lin, Zhichen Lin, Jiangchuan Wang, Ziyue Zhang, Yugeng Li, Xiaohua Li, Deliang Zhu, Kah-Wee Ang, Ming Fang, Wangying Xu, Qi Wang, Wenjie Yu, Qiang Liu, Shuangwu Huang
Summary: The use of plasmonic structure enhances the performance of MoS2-based devices, and in this study, a plasmonic-enhanced few-layer MoS2 photodetector was successfully prepared on a GaN substrate, demonstrating high responsivity and low noise.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Review
Chemistry, Physical
Heng Xiang, Yu-Chieh Chien, Yufei Shi, Kah-Wee Ang
Summary: The security of Internet-of-Things (IoT) is crucial in various aspects such as device-to-device communication, sensing and actuating, and information exchange. Conventional cryptographic algorithms and silicon-based security primitives are constantly challenged by evolving attack methods, thus the implementation of hardware security using 2D materials is worth exploring. This review summarizes the research progress in 2D material-based true random number generators (TRNGs), physical unclonable functions (PUFs), and other security applications, and discusses entropy sources, reliability, circuit, and machine learning modeling attacks on TRNGs and PUFs.
Review
Engineering, Electrical & Electronic
Li Chen, Mei Er Pam, Sifan Li, Kah-Wee Ang
Summary: Ferroelectric memory devices based on 2D materials are recognized as promising building blocks for brain-like neuromorphic computing due to their fast-switching speed and ultra-low power consumption. The unique properties of 2D materials and their high compatibility with existing technology make them potential candidates for extending state-of-the-art ferroelectric memory technology into atomic-thin scale.
NEUROMORPHIC COMPUTING AND ENGINEERING
(2022)