Article
Chemistry, Multidisciplinary
Xi Wan, EnZi Chen, Jie Yao, Mingliang Gao, Xin Miao, Shuai Wang, Yanyun Gu, Shaoqing Xiao, Runze Zhan, Kun Chen, Zefeng Chen, Xiaoliang Zeng, Xiaofeng Gu, Jianbin Xu
Summary: Janus transition-metal dichalcogenides (TMDCs) are special 2D materials with unique properties, and a controlled synthesis method has been developed with thorough investigation of their formation and properties. The electronic properties of this material, including the high intrinsic carrier concentration and Fermi level, are crucial for potential device applications.
Article
Chemistry, Physical
Shuhui Zhang, Xinxin Wang, Yuanyuan Wang, Haona Zhang, Baibiao Huang, Ying Dai, Wei Wei
Summary: This study investigates structural defects in 2D transition-metal dichalcogenides and finds that S and Se vacancies are the most favorable point defects. Line vacancies induce more dispersive in-gap states, and 60 degrees grain boundaries behave as one-dimensional metallic quantum wires.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Shuhui Zhang, Xinxin Wang, Yuanyuan Wang, Haona Zhang, Baibiao Huang, Ying Dai, Wei Wei
Summary: This work investigates the structural defects in two-dimensional transition-metal dichalcogenides (TMDCs) and finds that S and Se vacancies are the most favorable point defects which tend to aggregate to form line vacancies. Additionally, 60 degrees grain boundaries (GBs) behave as one-dimensional metallic quantum wires. Effectively controlling the formation of defects at the nanoscale brings new electronic characteristics and broadens the applications of 2D TMDCs.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Kaiying Dou, Wenhui Du, Zhonglin He, Ying Dai, Baibiao Huang, Yandong Ma
Summary: We report the identification of an antiferromagnetic skyrmion crystal (AF-SkX) in a two-dimensional lattice of the Janus monolayer CrSi2N2As2 through first-principles calculations and Monte Carlo simulations. The Janus monolayer CrSi2N2As2 exhibits a large Dzyaloshinskii-Moriya interaction due to the broken inversion symmetry and strong spin-orbit coupling. Combined with the geometric frustration of its triangular lattice, this leads to the formation of skyrmion physics and the long-sought AF-SkX in the presence of an external magnetic field. Furthermore, the creation and annihilation of AF-SkX in Janus monolayer CrSi2N2As2 can be achieved through ferroelectricity by contacting with Sc2CO2. These findings greatly enrich the research on antiferromagnetic skyrmions.
Article
Chemistry, Multidisciplinary
Si-Zhao Huang, Cheng-Ge Fang, Qing-Yi Feng, Bi-Yi Wang, Hong-Dong Yang, Bo Li, Xia Xiang, Xiao-Tao Zu, Hong-Xiang Deng
Summary: This study systematically explores the thermoelectric performance of the Janus ZrSSe monolayer under biaxial strain using first-principles approach and Boltzmann transport theory. The results demonstrate that the Janus ZrSSe monolayer has excellent stability and can be tuned by strain. The electronic structure and thermoelectric transport parameters can be significantly adjusted by biaxial strain. Under certain tensile strain, the monolayer exhibits high power factor and ZT values, making it a promising strain-tunable thermoelectric material.
Article
Chemistry, Physical
Fanjunjie Han, Xu Yan, Aitor Bergara, Wenjing Li, Hong Yu, Guochun Yang
Summary: Janus CrSSe monolayer, a newly discovered two-dimensional ferromagnetic half-metal, exhibits interesting magnetoelectric properties, including high Curie temperature, large magnetic anisotropy energy per Cr atom, and robust half-metallicity. It also shows obvious ferroelasticity and interesting multiferroic coupling between in-plane magnetization and ferroelasticity. Moreover, by replacing the Se/S atoms, two new half-metallic FM CrS2 and CrSe2 monolayers with excellent magnetoelectric properties were obtained. Therefore, this study provides a pathway to design novel multiferroic materials and enriches the understanding of 2D transition metal chalcogenides.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Applied
Zhijing Huang, Jose Manuel Perez Aguilar, Shuming Zeng, Yusong Tu, Zonglin Gu
Summary: This study investigates the structural characteristics and stability of MoSHx and finds stable MoSHx structures within a critical range of hydrogen atom ratios. It also observes a transition in the preferred adsorption sites of hydrogen atoms as the hydrogen atom ratio increases.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Yue-tong Han, Wei-xiao Ji, Pei-Ji Wang, Ping Li, Chang-Wen Zhang
Summary: By using first-principles calculations, we demonstrate that a significant Dzyaloshinskii-Moriya interaction (DMI) can be obtained in Janus monolayers of dichalcogenides XSeTe (X = Nb, Re), which is rare in two-dimensional magnetic materials. The DMI amplitudes of NbSeTe and ReSeTe monolayers are 1.78 meV and 4.82 meV, respectively, larger than the experimental value of Co/graphene (0.16 meV). Moreover, NbSeTe and ReSeTe monolayers have high Curie temperatures of 1023 K and 689 K, respectively. Through micromagnetic simulations, we also find that the ReSeTe monolayer can exhibit skyrmion states under an external magnetic field, and importantly, the skyrmion states can be regulated and controlled under external strain. These findings pave the way for device concepts using chiral magnetic structures in specially designed 2D ferromagnetic materials.
Article
Nanoscience & Nanotechnology
Huan Lou, Kaiwen Qiu, Guochun Yang
Summary: The Mo2P3 monolayer, with a Janus structure, shows good electrical conductivity and catalytic activity for efficient hydrogen production. It has a high density of active sites and remains stable under strain, making it a promising candidate for electrocatalytic water splitting.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Hui Zhang, Madisen Holbrook, Fei Cheng, Hyoungdo Nam, Mengke Liu, Chi-Ruei Pan, Damien West, Shengbai Zhang, Mei-Yin Chou, Chih-Kang Shih
Summary: The synthesis of a single atomic sheet of honeycomb structure BeO (h-BeO) grown on Ag(111) thin films on Si(111) wafers using molecular beam epitaxy (MBE) is reported. The h-BeO has a lattice constant of 2.65 A and an insulating band gap of 6 eV. Weak interaction between h-BeO layer and Ag(111) substrate is found, making h-BeO an attractive candidate for future technological applications.
Article
Multidisciplinary Sciences
Jiaojian Shi, Haowei Xu, Christian Heide, Changan HuangFu, Chenyi Xia, Felipe de Quesada, Hongzhi Shen, Tianyi Zhang, Leo Yu, Amalya Johnson, Fang Liu, Enzheng Shi, Liying Jiao, Tony Heinz, Shambhu Ghimire, Ju Li, Jing Kong, Yunfan Guo, Aaron M. Lindenberg
Summary: The authors report giant room-temperature nonlinearity enhancements in Janus transition metal dichalcogenides, which may be leveraged through electronic band topology. The giant nonlinear optical response is linked to topological band mixing and strong inversion symmetry breaking due to the Janus structure. This work defines general protocols for designing materials with large nonlinearities and heralds the applications of topological materials in optoelectronics.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Xiangchao Ma, Yi Tian, Pei Zhao, Xin Wu, Tao Jing, Jianqi Zhang
Summary: This study successfully synthesized a new 2D Janus MoCrSSe monolayer with an internal anti-ferromagnetic ground state. Magnetic moments originated from Cr atoms, and the anti-ferromagnetic coupling between them was strong. The MoCrSSe monolayer exhibited electronic insulating properties in the anti-ferromagnetic state, making it suitable for infrared photodetection, while becoming electrically conductive in the ferromagnetic state, suggesting its potential as a magnetic switch.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Yaxuan Wu, Qingquan Liu, Puyuan Shi, Jingjuan Su, Yungeng Zhang, Bing Wang
Summary: In this study, a Janus CrSSe ferromagnetic monolayer was systematically predicted using a global optimization evolutionary algorithm and density functional theory method. Monte Carlo simulations revealed that the Curie temperature of the Janus CrSSe monolayer is approximately 272 K and can be adjusted to 496 K with slight tensile biaxial strain. Additionally, this monolayer exhibits significant magnetic anisotropy energy (1.4 meV Cr-1) and can undergo a transition from ferromagnetic to antiferromagnetic order under compressive strain. Furthermore, it possesses the lowest energy in the 2D search space and demonstrates excellent thermal, dynamic, and mechanical stabilities.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Zhuyu Feng, Yuhong Huang, Shujing Lin, Hongkuang Yuan, Hong Chen
Summary: The thermoelectric transport properties of Janus monolayers M2P2S3Se3 (M = Zn and Cd) were studied using first-principles based transport theory. The Zn2P2S3Se3 and Cd2P2S3Se3 monolayers were found to be indirect-gap semiconductors. The lower lattice thermal conductivity (kappa(l)) of Zn2P2S3Se3 compared to Cd2P2S3Se3 was attributed to the softer Zn-Se/S bonds, which caused more pronounced flat modes in the phonon dispersion. The carrier transport in both monolayers was dominated by polar optical phonon scattering, resulting in a significant decrease in electrical conductivity and power factor. The predicted figure of merit (zT) increased with temperature and reached optimal values of 0.86 and 0.30 at 1200 K for n-type Zn2P2S3Se3 and Cd2P2S3Se3 monolayers, respectively, at specific electron densities.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Hengwei Qiu, Fu Li, Shan He, Ran Shi, Yaoyao Han, Hannikezi Abudukeremu, Lin Zhang, Yan Zhang, Song Wang, Wangyu Liu, Chao Ma, Honghua Fang, Run Long, Kaifeng Wu, Hao Zhang, Jinghong Li
Summary: This study reports the synthesis of uniform, epitaxially grown CsPbBr3/CdS Janus nanocrystal heterostructures with ultrafast charge separation across the electronically coupled interface. Each Janus nanocrystal contains a CdS domain that grows exclusively on a single {220} facet of CsPbBr3 nanocrystals. The promoted charge separation and extraction in epitaxial Janus nanocrystals leads to photoconductors with drastically improved responsivity and detectivity, which is promising for ultrasensitive photodetection.
Article
Chemistry, Multidisciplinary
Rania Harrabi, Thomas Halbritter, Fabien Aussenac, Ons Dakhlaoui, Johan van Tol, Krishna K. Damodaran, Daniel Lee, Subhradip Paul, Sabine Hediger, Frederic Mentink-Vigier, Snorri Th Sigurdsson, Gael De Paepe
Summary: Efficiently polarizing proton-dense molecular solids through dynamic nuclear polarization (DNP) solid-state NMR has been a great challenge. In this study, we introduce a new polarizing agent, cAsymPol-POK, which shows outstanding performance in polarizing biomolecular assemblies and organic microcrystals at high magnetic fields and fast magic angle spinning frequencies. Simulation and experimental results demonstrate the compatibility of cAsymPol-POK with challenging biomolecular applications and its ability to rapidly acquire crucial structural data of pharmaceutical drugs at natural isotopic abundance.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Materials Science, Multidisciplinary
Frederic Bonell, Alain Marty, Celine Vergnaud, Vincent Consonni, Hanako Okuno, Abdelkarim Ouerghi, Herye Boukari, Matthieu Jamet
Summary: This study reports the growth of highly oriented few-layers PtSe2 on ZnO(0001) and finds that PtSe2 films grown on insulating substrate ZnO(0001) have better structural quality. Hall measurements performed on the epitaxial ZnO/PtSe2 demonstrate good semiconductor behavior and high mobility.
Article
Nanoscience & Nanotechnology
Mario Ribeiro, Giulio Gentile, Alain Marty, Djordje Dosenovic, Hanako Okuno, Celine Vergnaud, Jean-Francois Jacquot, Denis Jalabert, Danilo Longo, Philippe Ohresser, Ali Hallal, Mairbek Chshiev, Olivier Boulle, Frederic Bonell, Matthieu Jamet
Summary: In this study, we successfully grew large-area single-crystal ultrathin films of stoichiometric Fe5GeTe2 on an insulating substrate using molecular beam epitaxy. Magnetic measurements showed that the films maintained ferromagnetic properties up to room temperature, with a Curie temperature of 293 K. Surface, chemical, and structural characterizations confirmed the layer-by-layer growth, 5:1:2 Fe:Ge:Te stoichiometric composition, and single-crystalline nature of the films.
NPJ 2D MATERIALS AND APPLICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Alexandros El Sachat, Peng Xiao, Davide Donadio, Frederic Bonell, Marianna Sledzinska, Alain Marty, Celine Vergnaud, Herve Boukari, Matthieu Jamet, Guillermo Arregui, Zekun Chen, Francesc Alzina, Clivia M. Sotomayor Torres, Emigdio Chavez-Angel
Summary: In this study, the influence of crystallinity and film thickness on the acoustic and thermal properties of layered PtSe2 films was investigated. The results showed that there is ballistic cross-plane heat transport up to around 30 layers of PtSe2, and a significant reduction in cross-plane thermal conductivity in polycrystalline films with thickness larger than 20 layers compared to crystalline films of the same thickness. The research also revealed a high degree of thermal conductivity anisotropy and a large contribution of optical phonons to the thermal conductivity in bulk and thin PtSe2 films.
NPJ 2D MATERIALS AND APPLICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Alessandro De Vita, Thao Thi Phuong Nguyen, Roberto Sant, Gian Marco Pierantozzi, Danila Amoroso, Chiara Bigi, Vincent Polewczyk, Giovanni Vinai, Loi T. Nguyen, Tai Kong, Jun Fujii, Ivana Vobornik, Nicholas B. Brookes, Giorgio Rossi, Robert J. Cava, Federico Mazzola, Kunihiko Yamauchi, Silvia Picozzi, Giancarlo Panaccione
Summary: This research investigates the ground state electronic properties of CrI3 and VI3 and reveals the stability of different electronic phases and the influence of dimensionality effects.
Article
Physics, Multidisciplinary
Simone Lisi, Val Prime Erie Guisset, Philippe David, Estelle Mazaleyrat, Ana Cristina Gomez Herrero, Johann Coraux
Summary: Confinement of lattices in two dimensions leads to various order and disorder phenomena. This study revisits the concept of orientational ordering and discovers a two-way twist of monolayers with increasing density in alkali atom monolayers confined between graphene and an iridium surface.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Adam N. Smith, Rania Harrabi, Thomas Halbritter, Daniel Lee, Fabien Aussenac, Patrick C. A. van der Wel, Sabine Hediger, Snorri Th. Sigurdsson, Gael De Paepe
Summary: We demonstrate a technique for acquiring multidimensional solid-state NMR 13C-13C correlation spectra of biomolecular assemblies and microcrystalline organic molecules at natural isotopic abundance using only milligram quantities of sample. This technique combines fast Magic Angle Spinning, low-power dipolar recoupling, and dynamic nuclear polarization with AsymPol biradicals as polarizing agents. These experiments are crucial for structural characterization as they provide information on short-and long-range distances. We showcase the effectiveness of this approach on various sample types, including polyglutamine fibrils involved in Huntington's disease and microcrystalline ampicillin, a small antibiotic molecule.
SOLID STATE NUCLEAR MAGNETIC RESONANCE
(2023)
Article
Chemistry, Multidisciplinary
Xiaorong Weng, Philippe David, Valerie Guisset, Lucio Martinel, Olivier Geaymond, Johann Corau, Gilles Renaud
Summary: This study investigates the structure of a two-dimensional single layer of tantalum sulfide grown on a Au(111) surface and its evolution during intercalation and deintercalation processes using in situ synchrotron grazing incidence X-ray diffraction and X-ray reflectivity. Intercalation decouples the system and increases its lattice parameter, while deintercalation recouples the two materials. The cyclic treatment with an H2S atmosphere improves the structural quality of the layer and induces rotation of some TaS2 flakes. These rotations result in additional superlattices with different diffraction patterns.
Article
Physics, Condensed Matter
R. Sant, A. De Vita, V Polewczyk, G. M. Pierantozzi, F. Mazzola, G. Vinai, G. van der Laan, G. Panaccione, N. B. Brookes
Summary: Polarization dependent x-ray absorption spectroscopy was used to study the magnetic ground state and orbital occupation in VI3 van der Waals crystals. The effects of symmetry reduction and hybridization between vanadium and ligand states were evaluated. The results suggest that the insulating ground state is stabilized by Mott correlation effects rather than a Jahn-Teller mechanism, and provide insights for studying the spectroscopic properties of other van der Waals halides.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Multidisciplinary Sciences
Minh Tuan Dau, Mohamed Al Khalfioui, Adrien Michon, Antoine Reserbat-Plantey, Stephane Vezian, Philippe Boucaud
Summary: New material descriptors are built using tree-based machine learning models to predict the band gap and work function of 2D materials. These descriptors are constructed by vectorizing property matrices and using empirical property functions, resulting in mixing features that require low-resource computations. When combined with database-based features, the mixing features significantly enhance the accuracy of the models in training and prediction.
SCIENTIFIC REPORTS
(2023)
Article
Materials Science, Multidisciplinary
Alexandre Artaud, Nicolas Rougemaille, Sergio Vlaic, Vincent T. Renard, Nicolae Atodiresei, Johann Coraux
Summary: Unlike conventional 2D semiconductor superlattices, moire patterns in 2D materials are flexible and their properties depend on their topography. Our study reveals that out-of-plane deformations of membranes in 2D materials can affect their electronic, magnetic, optical, and mechanical properties, and we have experimentally validated our predictions.
Article
Chemistry, Multidisciplinary
Debora Pierucci, Aymen Mahmoudi, Mathieu Silly, Federico Bisti, Fabrice Oehler, Gilles Patriarche, Frederic Bonell, Alain Marty, Celine Vergnaud, Matthieu Jamet, Herve Boukari, Emmanuel Lhuillier, Marco Pala, Abdelkarim Ouerghi
Summary: This study investigates the structural and electronic properties of single-layer WSe2 grown on a Se-terminated GaAs(111)B substrate using molecular beam epitaxy. The results show that the Se-terminated GaAs substrate can significantly tune the electronic properties of WSe2, leading to high p-type doping. This finding is important for applications in nanoelectronics and optoelectronics.
Article
Engineering, Electrical & Electronic
Emilio Velez-Fort, Ali Hallal, Roberto Sant, Thomas Guillet, Khasan Abdukayumov, Alain Marty, Celine Vergnaud, Jean-Francois Jacquot, Denis Jalabert, Jun Fujii, Ivana Vobornik, Julien Rault, Nicholas B. Brookes, Danilo Longo, Philippe Ohresser, Abdelkarim Ouerghi, Jean-Yves Veuillen, Pierre Mallet, Herve Boukari, Hanako Okuno, Mairbek Chshiev, Frederic Bonell, Matthieu Jamet
Summary: We report on a two-dimensional alloy V1-xPtxSe2 that exhibits ferromagnetic order and Rashba spin-orbit coupling. By substituting vanadium with platinum in VSe2, we restore ferromagnetic order down to one monolayer of V0.65Pt0.35Se2. Moreover, the presence of platinum atoms gives rise to Rashba spin-orbit coupling in (V,Pt)Se2, providing an original platform to study the interplay between ferromagnetism and spin-orbit coupling in the 2D limit.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
