Article
Nanoscience & Nanotechnology
Xin He, Chenhui Zhang, Dongxing Zheng, Peng Li, John Q. Xiao, Xixiang Zhang
Summary: With the recent advancements in two-dimensional ferromagnets, it is now feasible to develop high-quality all-2D spintronic devices. In this study, nonlocal spin valves were successfully fabricated using Fe3GeTe2 as the spin source and detector and multilayer graphene as the spin transport channel. The spin transport signal strongly depended on temperature and vanished below the Curie temperature of the Fe3GeTe2 flakes. Our results suggest potential applications of van der Waals heterostructures in spintronic devices.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Review
Chemistry, Multidisciplinary
Xiangdong Guo, Wei Lyu, Tinghan Chen, Yang Luo, Chenchen Wu, Bei Yang, Zhipei Sun, F. Javier Garcia de Abajo, Xiaoxia Yang, Qing Dai
Summary: 2D monolayers can be vertically stacked in van der Waals heterostructures to support a wide range of confined polaritons. This offers advantages in terms of controlling the constituent layers, stacking sequence, and twist angles. These heterostructures have extended the performance and functions of polaritons, and potential applications include nanophotonic integrated circuits.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Jia-Wei Chen, Yun-Guan Wei, Hung-Yang Lo, Sicheng Lu, Yi-Che Chen, Chi-Fong Lei, Po-Liang Liu, Pu Yu, Nien-Ti Tsou, Akira Yasuhara, Wen-Wei Wu, Ying-Hao Chu
Summary: Quasi van der Waals epitaxy is a method to construct combinations of 2D and 3D materials. The interface structure and mechanical robustness of metal/muscovite systems have been studied. The anisotropic thermal expansion and thermal stress tolerance in the silver/muscovite heteroepitaxy have been discovered and demonstrated. The electrothermal and photothermal methods show fast response to thermal stress, proving the interface robustness.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Vinicius G. Garcia, Nathanael N. Batista, Diego A. Aldave, Rodrigo B. Capaz, Juan Jose Palacios, Marcos G. Menezes, Wendel S. Paz
Summary: In this study, a van der Waals heterostructure consisting of isostructural nanoribbons of Sb2S3 and Sb2Se3 is demonstrated to have a direct band gap and a typical type-II band alignment, making it suitable for optoelectronics and solar energy conversion. Optical absorption spectra show broad profiles in the visible and UV ranges for all configurations, indicating their potential for photodevices.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Multidisciplinary Sciences
A. J. Sternbach, S. H. Chae, S. Latini, A. A. Rikhter, Y. Shao, B. Li, D. Rhodes, B. Kim, P. J. Schuck, X. Xu, X-Y Zhu, R. D. Averitt, J. Hone, M. M. Fogler, A. Rubio, D. N. Basov
Summary: Layered crystals, such as tungsten diselenide, can exhibit unconventional optical properties that allow for the propagation of subdiffractional waveguide modes with hyperbolic dispersion. This study demonstrates optically induced hyperbolicity in WSe2 and explores the role of quantum transitions of excitons in the observed polaritonic response.
Article
Chemistry, Multidisciplinary
Hideki Matsuoka, Stewart Edward Barnes, Jun'ichi Ieda, Sadamichi Maekawa, Mohammad Saeed Bahramy, Bruno Kenichi Saika, Yukiharu Takeda, Hiroki Wadati, Yue Wang, Satoshi Yoshida, Kyoko Ishizaka, Yoshihiro Iwasa, Masaki Nakano
Summary: This research presents strong out-of-plane magnetic anisotropy at the interface between two different vdW materials, and proposes a simple model to explain the observations. These results demonstrate a new magnetic proximity effect at the vdW interface, expanding the horizons of emergent phenomena achievable in vdW heterostructures.
Article
Chemistry, Physical
Bei Zhang
Summary: Rational design of model structure and effective strategy to overcome the mismatch between molecular orbital energy and Fermi level of electrodes are crucial for optimizing thermoelectric properties. The contact between a conjugated bis-phenylethynyl-anthrancene molecule and graphene nanoribbon electrodes, as well as nitrogen doping to adjust the Fermi level, leads to excellent thermoelectric performance in a single molecular junction.
APPLIED SURFACE SCIENCE
(2022)
Review
Chemistry, Multidisciplinary
Hui-Lei Hou, Cosimo Anichini, Paolo Samori, Alejandro Criado, Maurizio Prato
Summary: In the past 15 years, 2D materials have revolutionized materials science and become powerful components for high-performance chemical sensors. By forming van der Waals heterostructures (VDWHs), the individual drawbacks of 2D materials can be overcome, leading to superior sensitivities, selectivity, and stability. This review discusses the latest developments in chemical sensors based on VDWHs of 2D materials, including sensing mechanisms and future directions with potential impact in environmental sciences and biomedical applications.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Review
Chemistry, Multidisciplinary
Fang Wang, Tao Zhang, Runzhang Xie, Anna Liu, Fuxing Dai, Yue Chen, Tengfei Xu, Hailu Wang, Zhen Wang, Lei Liao, Jianlu Wang, Peng Zhou, Weida Hu
Summary: With the continuous advancement of nanofabrication techniques and the discovery of useful manipulation mechanisms in high-performance applications, the morphology and usage of junction devices in photodetectors have undergone fundamental revolution. New types of photodetectors, not relying on any junction, have emerged, offering high signal-to-noise ratio and multidimensional modulation. This review focuses on a unique category of material systems, van der Waals materials, which support novel high-performance photodetectors beyond junctions.
ADVANCED MATERIALS
(2023)
Article
Multidisciplinary Sciences
Long Zhang, Fengcheng Wu, Shaocong Hou, Zhe Zhang, Yu-Hsun Chou, Kenji Watanabe, Takashi Taniguchi, Stephen R. Forrest, Hui Deng
Summary: Controlling matter-light interactions with cavities is crucial in modern science and technology. By integrating MoSe2-WS2 heterobilayers in a microcavity, cooperative coupling between moire-lattice excitons and microcavity photons has been established, providing versatile control of both matter and light. This moire polariton system combines strong nonlinearity and microscopic-scale tuning of matter excitations, offering a platform to study collective phenomena from tunable arrays of quantum emitters.
Review
Chemistry, Multidisciplinary
Tianping Ying, Tongxu Yu, Yanpeng Qi, Xiaolong Chen, Hideo Hosono
Summary: By breaking traditional alloying strategy restrictions, the high entropy concept has expanded the field of alloy exploitation. This review focuses on the combination of the high entropy concept and van der Waals systems to create a new category of materials called high entropy van der Waals materials (HEX). The design strategy for HEX incorporates the local features of high entropy materials and the holistic degrees of freedom in van der Waals materials, successfully leading to the discovery of various high entropy compounds with desirable physical properties. Additionally, deliberate design of structural units and their stacking configuration in HEX can also enhance catalytic performance.
Article
Chemistry, Multidisciplinary
Peter Sutter, Larousse Khosravi Khorashad, Christos Argyropoulos, Eli Sutter
Summary: Ultrathin van der Waals semiconductors exhibit remarkable optoelectronic and photonic properties, making them attractive for photonic circuitry. Scanning near-field optical microscopy can overcome the limitations of conventional optics and characterize waveguide modes with high resolution.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Xiaoqing Chen, Yu Zhang, Ruijuan Tian, Xianghu Wu, Zhengdong Luo, Yan Liu, Xinran Wang, Jianlin Zhao, Xuetao Gan
Summary: A quadratically nonlinear photodetector (QNPD) composed of a van der Waals (vdW) stacked GaSe/InSe heterostructure is reported in this study. The QNPD exhibits unique electronic and optical attributes and extends the photodetection wavelength range from 900 to 1750 nm due to the extra second-harmonic generation (SHG) process in GaSe/InSe. It is highly sensitive to the variation of optical intensity and can be used as an autocorrelator for measuring ultrafast pulse widths and an optoelectronic mixer for signal processing.
Review
Materials Science, Multidisciplinary
Lixin Liu, Tianyou Zhai
Summary: The article reviews the latest research activities on wafer-scale vdWHs and their applications, outlining preparation strategies and applications to showcase their potential in electronic, optoelectronic, and flexible devices fields.
Article
Chemistry, Multidisciplinary
Jingrun Ran, Hongping Zhang, Jiangtao Qu, Jieqiong Shan, Kenneth Davey, Julie M. Cairney, Liqiang Jing, Shi-Zhang Qiao
Summary: This study introduces a ReS2/In2ZnS4 2D/2D van der Waals heterostructure with highly promoted photocatalytic H-2-evolution rate, making it one of the most efficient In2ZnS4-based photocatalysts. Advanced characterizations and theoretical computations demonstrate that the interlayer electronic interaction and atomic-level S active centers within the structure collaboratively boost light-induced H-2 evolution.
Article
Chemistry, Physical
P. Alvarez-Zapatero, A. Herrero, A. Lebon, L. J. Gallego, A. Vega
Summary: The study demonstrates that Li-decorated popgraphene can achieve stable hydrogen storage with reversible capabilities under moderate conditions. The Li-decorated popgraphene has a high density, meeting the threshold specified by the U.S. Department of Energy for novel hydrogen-storage materials.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Physics, Condensed Matter
Guiming Guo, Xiaolong Yang, Jesus Carrete, Wu Li
Summary: The thermal conductivity of nonmetals is determined by factors such as atomic mass and interatomic force constants. While heavier elements like Ge exhibit lower thermal conductivity due to factors like phonon lifetime, diamond's high thermal conductivity is not solely attributed to weak anharmonic scattering as previously thought. The study also highlights the comparable magnitude of the third-order interatomic force constants in diamond, Si, and Ge.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Physics, Multidisciplinary
Ashis Kundu, Xiaolong Yang, Jinlong Ma, Tianli Feng, Jesus Carrete, Xiulin Ruan, Georg K. H. Madsen, Wu Li
Summary: This study provides new insights into heat conduction in semimetallic solids, revealing that semimetallic theta-phase tantalum nitride (theta-TaN) has an ultrahigh thermal conductivity. Phonons are found to be the main heat carriers, and the high thermal conductivity relies on a combination of factors.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Medicinal
Hadrian Montes-Campos, Jesus Carrete, Sebastian Bichelmaier, Luis M. Varela, Georg K. H. Madsen
Summary: NEURALIL is an effective model for predicting the potential energy of ionic liquids, achieving accurate results with significant savings in computational cost by training on ab initio forces. By utilizing appropriate descriptor encoding and force information, higher accuracy is achieved, reducing the amount of data required for training.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2022)
Article
Physics, Condensed Matter
Lijun Pan, Jesus Carrete, Zhao Wang
Summary: In this study, the effect of biaxial tensile strain on phonon transport in a Janus PtSTe monolayer was investigated using first-principles calculations and Boltzmann transport theory. It was found that the lattice thermal conductivity decreases nonlinearly with increasing strain, reaching close to an order of magnitude reduction when the band gap disappears completely under high strains (>8%). This behavior is attributed to a strong enhancement of anharmonic scattering of acoustic phonons due to the band overlap.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Materials Science, Multidisciplinary
Sebastian Bichelmaier, Jesus Carrete, Michael Nelhiebel, Georg K. H. Madsen
Summary: A method based on effective harmonic potentials is proposed to study the potential energy surface of anharmonic materials, and an introduction of reweighting procedure enables the usage of unregularized regression. The method is tested on the high-temperature cubic phase of HfO2 and the calculated temperature-dependent physical properties are in agreement with existing experimental data, suggesting the potential for predictive treatment of HfO2 over a wide temperature range.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Lijun Pan, Zhao Wang, Jesus Carrete, Georg K. H. Madsen
Summary: Ab initio calculations were used to study the phonon and charge-carrier transport in the Janus PtSTe monolayer. The results showed a significant improvement in the thermoelectric performance, mainly due to the reduction in thermal conductivity resulting from the relaxation of selection rules for three-phonon scattering. This suggests that Janus monolayers have great potential for thermoelectric applications among quasi-two-dimensional systems.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Computer Science, Interdisciplinary Applications
Marti Raya-Moreno, Xavier Cartoixa, Jesus Carrete
Summary: We introduce BTE-Barna, a software package that extends the MC module of the almaBTE solver for phonon transport in nanosystems based on 2D materials. It incorporates the propagator for the full linearized version of the PBTE, allowing accurate modeling of scattering-induced phonon occupation evolution in momentum space. The code can find solutions for finite and extended devices with thermal gradients, isothermal reservoirs, or arbitrary initial temperature distributions, providing temperature and heat flux distributions as well as their spectral decompositions.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Sebastian Bichelmaier, Jesus Carrete, Georg K. H. Madsen
Summary: Given the high cost of ab-initio calculations, it is challenging to predict temperature-dependent phenomena in strongly anharmonic systems. A possible solution is to use a relatively inexpensive surrogate model for the potential energy surface to build temperature-dependent effective harmonic potentials. However, the results may only be valid in a narrow temperature range due to the limited flexibility of polynomials as approximants, leading to significant artifacts in derived quantities. A global interpolation strategy, such as a neural-network force field, is suggested as a better approach to cost-effective surrogate models.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2023)
Article
Chemistry, Physical
Jesus Carrete, Hadrian Montes-Campos, Ralf Wanzenboeck, Esther Heid, Georg K. H. Madsen
Summary: A reliable uncertainty estimator is crucial for using machine-learning force fields effectively. This study proposes a generalized deep-ensemble design using multiheaded neural networks and a heteroscedastic loss to handle uncertainties in energy and forces and consider aleatoric uncertainty sources in training data. Uncertainty metrics are compared for deep ensembles, committees, and bootstrap-aggregation ensembles using data for an ionic liquid and a perovskite surface. An adversarial approach to active learning is demonstrated for progressively refining force fields, made possible by fast training with residual learning and a nonlinear learned optimizer.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Raveena Gupta, Sonali Kakkar, Bonny Dongre, Jesus Carrete, Chandan Bera
Summary: Nanostructuring is a well-known method to improve the thermoelectric figure of merit, but it has limitations in tuning the lattice thermal conductivity. The thermoelectric properties of the SnS monolayer are investigated under uniaxial compressive and tensile strains using first-principles calculations and the Boltzmann transport equation. It is found that applying uniaxial compressible and tensile strains along the armchair direction can significantly enhance the power factor and figure of merit of the material, making it a promising candidate for thermoelectric applications.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Sebastian Bichelmaier, Jesus Carrete, Ralf Wanzenboeck, Florian Buchner, Georg K. H. Madsen
Summary: This study explores the complex phase structure of HfO2 using effective harmonic potentials based on a neural-network force field (NNFF), providing almost ab-initio accuracy at a reduced cost. The results show that the thermal expansion coefficient of low-symmetry phases agrees with experimental results, and the P4 over bar 3m phase is identified as the favorable cubic phase. However, the experimental lattice constants of the cubic phases are larger than the calculated values for the corresponding stoichiometric phases. Furthermore, the stoichiometric cubic phases are unlikely to be thermodynamically stable compared to other phases.
Article
Materials Science, Multidisciplinary
Bonny Dongre, Jesus Carrete, Natalio Mingo, Georg K. H. Madsen
Summary: In this study, we calculate and analyze the lattice thermal conductivity of cubic group-III phosphides. We find that there is a significant disagreement in the literature values for GaP, which can be attributed to the incomplete consideration of long-range interactions and four-phonon scattering. By taking these factors into account, we obtain a calculated thermal conductivity that is in good agreement with the experimental value, highlighting the importance of convergence tests in the calculation process.
Article
Materials Science, Multidisciplinary
Marti Raya-Moreno, Jesus Carrete, Xavier Cartoixa
Summary: This study investigates the features arising from hydrodynamic effects in graphene and phosphorene devices with finite heat sources. The authors go beyond Callaway's model and solve the phonon Boltzmann transport equation to determine the full linearized scattering operator. They find that boundary scattering and the relation of sample dimensions to the nonlocal length l are the determining factors for these hydrodynamic features. The nonlocal length l reflects the ability of scattering to randomize the heat flux, and approximations made on the scattering operator may have qualitative consequences on the signatures of hydrodynamic behavior.
Article
Materials Science, Multidisciplinary
Tiantian Jia, Jesus Carrete, Georg K. H. Madsen, Yongsheng Zhang, Su-Huai Wei
Summary: The thermoelectric properties of three pyrite-type IIB-VIA(2) dichalcogenides were systematically investigated, and their ultralow lattice thermal conductivities were attributed to soft phonon modes and strong anharmonicity. The compounds also exhibited complex energy isosurfaces that allowed for both large density-of-states effective masses and small conductivity effective masses, leading to high figures of merit. This study provides insights into the thermal and electrical transport properties of pyrite-type dichalcogenides and their potential for optimizing the thermoelectric properties of other compounds in the future.
