Article
Chemistry, Multidisciplinary
Eli Sutter, Hannu-Pekka Komsa, Alexander A. Puretzky, Raymond R. Unocic, Peter Sutter
Summary: Breaking symmetry in van der Waals crystals through layer stacking offers a promising approach for designing new ferroelectric materials.
Article
Chemistry, Multidisciplinary
Eli Sutter, Peter Sutter
Summary: The integration of dissimilar materials into heterostructures is a main focus in modern materials science and technology. By combining 1D nanowires and 2D plates, mixed-dimensional heterostructures can be created with varying composition and dimensionality, resulting in larger contrast in electronic structures. Previous methods required multi-step growth processes, but this study demonstrates a single-step growth process using differences in precursor incorporation rates to synthesize mixed-dimensional heterostructures. This new approach opens up possibilities for complex heteroarchitectures.
Article
Chemistry, Multidisciplinary
Yanbing Zhu, Daniel A. Rehn, Evan R. Antoniuk, Gowoon Cheon, Rodrigo Freitas, Aditi Krishnapriyan, Evan J. Reed
Summary: Research has shown that one-dimensional van der Waals materials may retain their bulk properties, and certain 1D substances can be distinguished from bulk materials, with potential for various applications.
Article
Chemistry, Multidisciplinary
Jia-Min Lai, Yu-Jia Sun, Qing-Hai Tan, Ping-Heng Tan, Jun Zhang
Summary: Laser cooling has been widely used in fundamental physics, precision metrology, and quantum science. However, cooling certain lattice vibrations remains a challenge due to the complexity of solid structures. Researchers have successfully demonstrated Raman cooling in a two-dimensional semiconductor, opening up new possibilities for cooling and controlling phonons.
Article
Nanoscience & Nanotechnology
Jung Ho Kim, Gang Hee Han, Byoung Hee Moon
Summary: van der Waals (vdW) layered materials have unique and variable properties, making them promising for future optoelectronic applications. In this study, we investigate multilayer germanium arsenide (GeAs), an emerging p-type vdW layered material. We demonstrate efficient hole transport in a multilayer GeAs field-effect transistor and the creation of a p-n photodiode with a vertical heterojunction of multilayer GeAs and n-type MoS2 monolayer, showing a photovoltaic response. These findings highlight the potential of 2D GeAs as a p-type material in vdW optoelectronic devices.
Article
Nanoscience & Nanotechnology
Jacopo Oswald, Davide Beretta, Michael Stiefel, Roman Furrer, Alessia Romio, Michel Daher Mansour, Dominique Vuillaume, Michel Calame
Summary: This work investigates the charge injection and transport across Au/OSC/Gr vertical heterostructures, where the PMMA-free graphene layer functions as the top electrode. The research shows that the charge transport is limited by thermionic emission at high bias and by space charge at low bias.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Xuan Zhou, Yinjie Ruan, Handi Yin, Yue Sun, Bin Lv, Guofeng Cheng
Summary: A novel van der Waals brown semitransparent semiconductor, InTeI single crystal, was synthesized and characterized for its structure and optical properties in this study. The results indicate a potential applicability of InTeI in the photovoltaic field.
Article
Chemistry, Multidisciplinary
Ryusuke Natsui, Hiroshi Shimizu, Yusuke Nakanishi, Zheng Liu, Akito Shimamura, Nguyen Tuan Hung, Yung-Chang Lin, Takahiko Endo, Jiang Pu, Iori Kikuchi, Taishi Takenobu, Susumu Okada, Kazu Suenaga, Riichiro Saito, Yasumitsu Miyata
Summary: This study presents a versatile method to fabricate nanoscale-thick bundles of indium-intercalated tungsten hexachalcogenide (W6Te6) wires. These bundles exhibit metallic behavior and mechanical flexibility, making them promising building blocks for integrated nanocircuits.
Article
Chemistry, Multidisciplinary
Jiachao Zhou, Anzhe Chen, Yishu Zhang, Dong Pu, Baoshi Qiao, Jiayang Hu, Hanxi Li, Shuai Zhong, Rong Zhao, Fei Xue, Yang Xu, Kian Ping Loh, Hua Wang, Bin Yu
Summary: The recently discovered ferroionic phenomena in 2D van der Waals copper-indium-thiophosphate (CIPS) have attracted widespread interest due to their potential for dynamic control of conductive switching properties, which is highly desirable for paradigm-shift computing. The intricate couplings between ferroelectric polarization and ionic conduction in 2D CIPS allow for manipulation and dynamic control of conductive behaviors. However, the complex interplays and underlying mechanisms are not fully understood yet.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jiachao Zhou, Anzhe Chen, Yishu Zhang, Dong Pu, Baoshi Qiao, Jiayang Hu, Hanxi Li, Shuai Zhong, Rong Zhao, Fei Xue, Yang Xu, Kian Ping Loh, Hua Wang, Bin Yu
Summary: This study investigates polarization switching and ionic conduction in 2D vdW CIPS and discovers that the conducting mechanisms can be divided into four states. It demonstrates that dynamically-tunable synaptic responsive behavior can be achieved through controlling the working-state transition.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Yuri Shakhman, Ilan Shumilin, Daniel Harries
Summary: To cope with stress induced by high salinity and hydrostatic pressure, marine animals accumulate osmolytes. This study focuses on the mechanism of urea's action on lipid membranes and its interaction with trimethylamine N-oxide (TMAO). It is found that urea weakens the van der Waals attraction between bilayers and the effects of urea and TMAO are largely additive. This research is important in understanding the role of osmolytes in lipid adhesion and fusion.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Biotechnology & Applied Microbiology
Zhang Yi, Yu Hongda, Sun Mengdi, Xu Yong
Summary: This paper presents a hybrid swarming algorithm that combines Ant Colony Optimization and Physarum Polycephalum Algorithm, and introduces the use of Van Der Waals force in the pheromone update mechanism. The improved algorithm prevents premature convergence into local optima and has demonstrated excellent accuracy and convergence time in simulations. Comparison with other advanced algorithms also indicates its superior performance. The robustness and versatility of the hybrid algorithm are further verified using the capitals of 35 Asian countries.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Junyi Liao, Wen Wen, Juanxia Wu, Yaming Zhou, Sabir Hussain, Haowen Hu, Jiawei Li, Adeel Liaqat, Hongwei Zhu, Liying Jiao, Qiang Zheng, Liming Xie
Summary: We have designed an in-memory computing device, MOfeS-FET, based on van der Waals ferroelectric semiconductor (InSe), which integrates memory and logic functions in the same material. It shows long retention time, high on/off ratios, stable cyclic endurance, and is capable of performing inverter, programmable NAND, and NOR Boolean logic operations with nonvolatile storage of the results.
Article
Chemistry, Multidisciplinary
Xiankun Zhang, Huihui Yu, Wenhui Tang, Xiaofu Wei, Li Gao, Mengyu Hong, Qingliang Liao, Zhuo Kang, Zheng Zhang, Yue Zhang
Summary: This study reported a van-der-Waals barrier-free hole contact between p-type tellurene semiconductor and layered 1T'-WS2 semimetal, achieving a zero Schottky barrier height and high field-effect mobility, providing a feasible strategy for eliminating the Schottky barrier of metal-semiconductor contacts.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Eli Sutter, Raymond R. Unocic, Juan-Carlos Idrobo, Peter Sutter
Summary: Research demonstrates multilayer heterostructures of van der Waals semiconductors with lateral interfaces, featuring sharp and laterally localized interfaces, as well as showing evidence of rapid transfer of electron-hole pairs across interfaces.
Article
Chemistry, Multidisciplinary
Ying-Chun Shen, Cheng-Yu Lee, Hsing-Hsiang Wang, Ming-Hsuan Kao, Po-Cheng Hou, Yen-Yu Chen, Wen-Hsien Huang, Chang-Hong Shen, Yu-Lun Chueh
Summary: Researchers have developed a flexible photodetector based on a two-dimensional Sb2Se3 film, which exhibits high photosensing current and detection ranges from visible to near-infrared. The photodetector was fabricated using an efficient field-effect transistor platform and showed quick response times and broadband absorption.
Article
Physics, Applied
T. Schenkel, A. M. Snijders, K. Nakamura, P. A. Seidl, B. Mak, L. Obst-Huebl, H. Knobel, I. Pong, A. Persaud, J. van Tilborg, T. Ostermayr, S. Steinke, E. A. Blakely, Q. Ji, A. Javey, R. Kapadia, C. G. R. Geddes, E. Esarey
Summary: Nanostructured surfaces increase ion yields in MALDI-MS. The spike protein complex, S1, is a fingerprint signature of Sars-CoV-2 with a mass of 75 kDa. We demonstrate a 50-fold enhancement in MALDI-MS yields of Sars-CoV-2 spike protein ions in the 100 kDa range when the matrix-analyte solution is placed on substrates coated with a dense forest of multi-walled carbon nanotubes, compared to uncoated substrates. Nanostructured substrates have the potential to advance mass spectrometry techniques for sensitive pathogen detection and environmental monitoring.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Environmental
Wen-Jun Niu, Ying-Yun Yan, Ru-Ji Li, Wei-Wei Zhao, Jiang-Lei Chen, Ming-Jin Liu, Bingni Gu, Wen-Wu Liu, Yu-Lun Chueh
Summary: In this proof-of-concept study, Fe nanoparticles encapsulated by nitrogen-doped carbon were evaluated and compared to Fe single atoms for boosting the catalytic activity of the oxygen reduction reaction (ORR) in Znair batteries. The Fe single atoms and Fe nanoparticles embedded in nitrogen-doped carbon exhibited excellent ORR performance with good stability and remarkable methanol tolerance. The strong interaction between the atomically dispersed Fe-Nx and adjacent Fe nanoparticles alters the electronic structure and enhances the electrocatalytic kinetics.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Mayur Chaudhary, Tzu-Yi Yang, Chieh-Ting Chen, Po-Chien Lai, Yu-Chieh Hsu, Yu-Ren Peng, Ashish Kumar, Chih-Hao Lee, Yu-Lun Chueh
Summary: This study demonstrates that the diffusion of metal ions can be modulated by defects in the switching medium, leading to the confinement of metal filaments in a precise 1D channel. This filament confinement achieved through defect engineering enables two interchangeable switching modes and could potentially address speed, size, and energy issues in computing.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yunchao Xu, Yiming Shi, Chuan Qian, Pengshan Xie, Chenxing Jin, Xiaofang Shi, Gengming Zhang, Wanrong Liu, Changjin Wan, Johnny C. Ho, Jia Sun, Junliang Yang
Summary: In this study, a novel optically readable organic electrochemical synaptic transistor (OR-OEST) strategy is proposed. The electrochemical doping mechanism of the device is systematically investigated, and basic biological synaptic behaviors that can be read by optical means are successfully achieved. The flexible OR-OESTs can electrically switch the transparency of semiconductor channel materials in a nonvolatile manner, enabling multilevel memory through optical readout. Moreover, the OR-OESTs are applied for preprocessing photonic images, such as contrast enhancement and denoising, and achieve a recognition rate of over 90% when fed into an artificial neural network.
Article
Nanoscience & Nanotechnology
Naoki Higashitarumizu, Shiekh Zia Uddin, Daniel Weinberg, Nima Sefidmooye Azar, I. K. M. Reaz Rahman, Vivian Wang, Kenneth B. B. Crozier, Eran Rabani, Ali Javey
Summary: The photophysics of black phosphorus, an optoelectronic material, was investigated. It was found that the photoluminescence quantum yield initially decreases with decreasing thickness due to enhanced surface carrier recombination, but sharply increases afterwards. Furthermore, black phosphorus exhibits a much lower surface carrier recombination velocity compared to other semiconductors.
NATURE NANOTECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
You Meng, Xiaocui Li, Xiaolin Kang, Wanpeng Li, Wei Wang, Zhengxun Lai, Weijun Wang, Quan Quan, Xiuming Bu, SenPo Yip, Pengshan Xie, Dong Chen, Dengji Li, Fei Wang, Chi-Fung Yeung, Changyong Lan, Chuntai Liu, Lifan Shen, Yang Lu, Furong Chen, Chun-Yuen Wong, Johnny C. Ho
Summary: The authors explore the unique multi-scale van der Waals interactions in one-dimensional tellurium systems to overcome the restrictions imposed by chemical bonds. They succeed in synthesizing wafer-scale van der Waals nanomeshes composed of self-welding Te nanowires on various substrates at a low temperature, which exhibit improved transport and photoelectric properties. These Te vdWs nanomesh electronics hold great promise in meeting emerging technological demands.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Vivian Wang, Shiekh Zia Uddin, Junho Park, Ali Javey
Summary: In this work, a highly multicolored light-emitting array with 49 different, individually addressable colors on a single chip is demonstrated. The array consists of pulsed-driven metal-oxide-semiconductor capacitors that generate electroluminescence from microdispensed materials, allowing arbitrary light spectra to be generated across a broad wavelength range. When combined with compressive reconstruction algorithms, these arrays can be used for compact spectroscopic measurements without diffractive optics. As an example, microscale spectral imaging of samples is demonstrated using a multiplexed electroluminescent array in conjunction with a monochrome camera.
Article
Nanoscience & Nanotechnology
Yunpeng Xia, Jiajia Zha, Haoxin Huang, Huide Wang, Peng Yang, Long Zheng, Zhuomin Zhang, Zhengbao Yang, Ye Chen, Hau Ping Chan, Johnny C. C. Ho, Chaoliang Tan
Summary: This study explores the effect of different crystal phases of MoTe2 as the charge-trapping layer in 2D van der Waals heterostructure-based flash memory devices. It is found that the device based on MoS2/h-BN/1T'-MoTe2 exhibits better performance than the device based on MoS2/h-BN/2H-MoTe2, including a larger memory window, faster switching speed, and higher extinction ratio. This research demonstrates that the crystal phase of 2D TMDs has a significant impact on the performance of nonvolatile flash memory devices based on 2D vdW heterostructures.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Xiaocui Li, You Meng, Wanpeng Li, Jun Zhang, Chaoqun Dang, Heyi Wang, Shih-Wei Hung, Rong Fan, Fu-Rong Chen, Shijun Zhao, Johnny C. Ho, Yang Lu
Summary: All-inorganic lead halide perovskites (CsPbX3) have attracted attention for energy conversion due to their outstanding performance and enhanced environmental stability. In this study, single-crystal CsPbX3 micropillars were successfully morphed into various shapes without causing cleavage or cracks. This exceptional plasticity is enabled by the slips of partial dislocations on multiple {110} planes.
Article
Chemistry, Multidisciplinary
Xiuming Bu, Di Yin, Dong Chen, Quan Quan, Zhe Yang, Senpo Yip, Chun-Yuen Wong, Xianying Wang, Johnny C. Ho
Summary: In this study, ternary Ni2P/MoNiP2/MoP crystalline/amorphous heterostructure nanowires were prepared on a conductive substrate using a facile H-2-assisted method. The content of the MoNiP2 phase and the crystallinity of the MoP phase can be tuned by controlling the H-2 concentration. The obtained electrocatalyst exhibits superior alkaline hydrogen evolution reaction performance, with high stability and optimized hydrogen adsorption/desorption kinetics.
Article
Materials Science, Multidisciplinary
Ashwin Aggarwal, Manik Dautta, Luis Fernando Ayala-Cardona, Aalaya Wudaru, Ali Javey
Summary: The rapid advancements in wearable technologies have enabled the development of personal monitoring systems for core bodily metrics. Current smartwatches accurately monitor physical signals like heart rate and respiratory rate, but they are unable to track several important physiological parameters, including sweat rate. This study presents a new wearable device that can track sweat rate using an off-the-shelf humidity sensor. The device features a 3D-printed chamber with a humidity sensor and microheater, and it interfaces with the skin using a malleable and concave sweat collector. Through experiments, the authors aim to understand the relationship between sweat-induced humidity and the amount of sweat secreted. Compared to existing sweat rate sensing devices, this hygrometer-based device is more comfortable for extended wear and can be used alongside microfluidic-based sweat rate devices.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Sujit Kumer Shil, Fei Wang, Kingsley O. Egbo, Ying Wang, Cheuk Kai Gary Kwok, Sai-W. Tsang, Johnny C. Ho, Kin Man Yu
Summary: This work reports the synthesis and properties of Pb-free all-inorganic Cs3Sb2X9 perovskite thin films (X = I, Br) by a two-step CVD approach. These films exhibit good crystallinity and high exciton binding energies with large Stokes shifts. The optical bandgaps and refractive indices of the films were also determined. Photoconductive devices fabricated using these films exhibited commendable performance with high responsivity and detectivity, as well as stable switching properties. The long-term stability of the thin films, even without encapsulation, suggests their potential for various optoelectronic devices.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Xia Shen, Qihang Lv, Qian Yang, Jie Fan, Xiaohang Song, Pengfei Guo, Pu Li, Johnny C. C. Ho, Kin Man Yu
Summary: A two-step growth of CdSxSe1-x alloy nanoribbon heterostructures along the lateral direction by an improved two-step magnetic-pulling chemical vapor deposition (CVD) method is reported. Photoluminescence spectrum and 2D emission mapping at the junctions show two different emission bands at 555 and 603 nm, which show agreement with the structural characterization results. Additionally, photodetectors based on these achieved nanoribbons exhibit great performance of high responsivity, high external quantum efficiency, fast response speed, and high I-on/I-off ratio.
ADVANCED PHOTONICS RESEARCH
(2023)
Article
Chemistry, Physical
Guofa Dong, Tingting Chen, Fengyan Xie, Donglin Xue, Tingyan Liu, Long Chen, Jianrong Xia, Shaowu Du, Fengyun Wang, Feng Xie, Johnny C. Ho
Summary: In this study, highly efficient and stable bifunctional electrocatalysts for overall water splitting were developed using NiFeP composites supported on Ni foam. The unique heterostructures in the composite contribute to its high electrocatalytic activity in hydrogen and oxygen evolution reactions. The composite shows promising potential for large-scale application in hydrogen energy utilization.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
