Article
Nanoscience & Nanotechnology
Jung-Hong Min, Kuang-Hui Li, Yong-Hyeon Kim, Jung-Wook Min, Chun Hong Kang, Kyoung-Ho Kim, Jae-Seong Lee, Kwang Jae Lee, Seong-Min Jeong, Dong-Seon Lee, Si-Young Bae, Tien Khee Ng, Boon S. Ooi
Summary: This study reports the spontaneous exfoliation of a large-area beta-Ga2O3 nanomembrane from compressive-strained epitaxial graphene grown on SiC, and demonstrates high-responsivity flexible solar-blind photodetectors.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Pilkyung Moon
Summary: We investigate the electronic structures of chiral twisted van der Waals atomic layers, focusing on chiral twisted graphite (CTG), and find that each CTG can host infinitely many resonant states with screw rotational symmetry and reduced Brillouin zone; regardless of the twist angle, the energies and wave functions of the resonant states can be described in a universal form of a one-dimensional chain, exhibiting a clear optical selection rule for circularly polarized light.
Article
Engineering, Mechanical
Guoliang Ru, Weihong Qi, Yaru Wei, Kewei Tang, Taowen Xue
Summary: The study reveals that the superlubricity properties in two-dimensional tellurene isomers and tellurene-graphene heterostructures vary significantly, with the friction coefficient of stacking G/13-Te being affected by different stacking structures, while superlubricity can be achieved in a wider range of interlayer angles in the G/?-Te system.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Chemistry, Multidisciplinary
Wenjing Yan, Andrey Akimov, Maria Barra-Burillo, Manfred Bayer, Jonathan Bradford, Vitalyi E. Gusev, Luis E. Hueso, Anthony Kent, Serhii Kukhtaruk, Achim Nadzeyka, Amalia Patane, Andrew W. Rushforth, Alexey Scherbakov, Dmytro D. Yaremkevich, Tetiana L. Linnik
Summary: Strain engineering using coherent phonons allows for the control of physical properties in 2D-vdW crystals, with the creation of flexural phononic crystals through periodic modulation of elastic coupling in vdW layers. Using an ultrafast pump-probe technique, we have successfully generated and detected these phonons, providing exciting prospects for ultrafast manipulation of states in 2D materials for emerging quantum technologies.
Article
Chemistry, Multidisciplinary
Bing Zhao, Roselle Ngaloy, Sukanya Ghosh, Soheil Ershadrad, Rahul Gupta, Khadiza Ali, Anamul Md. Hoque, Bogdan Karpiak, Dmitrii Khokhriakov, Craig Polley, Balasubramanian Thiagarajan, Alexei Kalaboukhov, Peter Svedlindh, Biplab Sanyal, Saroj P. Dash
Summary: This article demonstrates the robust room-temperature operation of lateral spin-valve devices using the vdW ferromagnet Fe5GeTe2 in heterostructures with graphene. Spin-dynamics measurements reveal multidirectional spin polarization at the Fe5GeTe2/graphene interface. Density functional theory calculations and Monte Carlo simulations reveal significantly canted Fe magnetic moments in Fe5GeTe2 along with the presence of negative spin polarization at the interface. These findings open opportunities for vdW interface design and applications of vdW-magnet-based spintronic devices at ambient temperatures.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
He Hao, Miao-Ling Lin, Bo Xu, Heng Wu, Yuechen Wang, Hailin Peng, Ping-Heng Tan, Lianming Tong, Jin Zhang
Summary: The characterization of interlayer coupling in two-dimensional van der Waals heterostructures (vdWHs) is crucial for understanding their quantum behaviors and structural functionalities. Twisted bilayer graphene (tBLG) provides a universal strategy to enhance layer-breathing (LB) phonons in vdWHs. By resonantly exciting electrons in tBLG, LB phonons extended over the entire layers in vdWHs can be strongly coupled, and this coupling can be tuned by the twist angle of tBLG. This method of enhancing LB phonons by tBLG is promising for investigating electron-phonon coupling and interlayer interaction in related vdWHs.
Article
Chemistry, Multidisciplinary
Zouhour Ben Jabra, Mathieu Abel, Filippo Fabbri, Jean-Noel Aqua, Mathieu Koudia, Adrien Michon, Paola Castrucci, Antoine Ronda, Holger Vach, Maurizio De Crescenzi, Isabelle Berbezier
Summary: This study investigates the growth of silicon on a chemically vapor deposited epitaxial graphene substrate and shows that the control of almost defect-free graphene is crucial for the growth of silicene. It is found that large silicene sheets can be formed at low coverages, while dendritic islands of silicon appear at higher coverages.
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
Xiangshun Geng, Peigen Zhang, Jun Ren, Guan-Hua Dun, Yuanyuan Li, Jialun Jin, Chaolun Wang, Xing Wu, Dan Xie, He Tian, Yi Yang, Tian-Ling Ren
Summary: In this study, a monolithic integrated graphene/perovskite heterojunction device was fabricated by directly growing a single-crystal hybrid perovskite on monolayer graphene. The device exhibited self-powering behavior and prominent photoresponse properties.
Article
Chemistry, Multidisciplinary
Zongqi Bai, Yang Xiao, Qing Luo, Miaomiao Li, Gang Peng, Zhihong Zhu, Fang Luo, Mengjian Zhu, Shiqiao Qin, Kostya Novoselov
Summary: The emergence of two-dimensional materials has led to important applications in electronic and optoelectronic devices. However, there are limitations such as low ON/OFF ratio and Schottky barrier formation. In this study, highly tunable field-effect tunneling transistors based on vertical graphene-WS2-graphene heterostructures were demonstrated, overcoming these limitations and achieving low off-state current, high ON/OFF ratio, and controllable carrier transport polarity.
Article
Chemistry, Multidisciplinary
Dianyu Qi, Peng Li, Haohui Ou, Di Wu, Weiguang Lian, Zhuo Wang, Fangping Ouyang, Yang Chai, Wenjing Zhang
Summary: Through a graphene-enhanced van der Waals integration approach, high-quality contacts with low contact resistances have been realized for both p- and n-type 2D FETs. This approach has achieved record on-state current densities in MoTe2, black phosphorus, and MoS2 FETs.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Mengying Bian, Liang Zhu, Xiao Wang, Junho Choi, Rajesh Chopdekar, Sichen Wei, Lishu Wu, Chang Huai, Austin Marga, Qishuo Yang, Yuguang C. Li, Fei Yao, Ting Yu, Scott A. Crooker, Xuemei M. Cheng, Renat F. Sabirianov, Shengbai Zhang, Junhao Lin, Yanglong Hou, Hao Zeng
Summary: Realizing van der Waals (vdW) epitaxy provides a breakthrough in circumventing the stringent lattice matching and processing compatibility requirements in conventional covalent heteroepitaxy. This study reports the epitaxial growth of covalent Cr5Te8 2D crystals on vdW WSe2, driven by interfacial dative bond formation. The concept of dative epitaxy is established, which combines the advantages of covalent epitaxy and vdW epitaxy while overcoming their limitations.
ADVANCED MATERIALS
(2022)
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
Nanoscience & Nanotechnology
Sergey G. Menabde, Jacob T. Heiden, Joel D. Cox, N. Asger Mortensen, Min Seok Jang
Summary: Polaritonic modes in low-dimensional materials enable strong light-matter interactions and the manipulation of light on nanometer length scales. The recent interest in image polaritons in van der Waals crystals has gained considerable attention in nanophotonics, where a polaritonic material couples with its mirror image in close proximity to a highly conductive metal. These image modes provide an appealing nanophotonic platform with lower propagation loss and access to the nonlocal regime of light-matter interaction.
Article
Polymer Science
Zirui Wang, Weilong Sun, He Zhang, Abhishek Tyagi, Frank Leung-Yuk Lam, Runlai Li
Summary: This paper presents a novel method for directly transferring large-area monolayer graphene onto polyethylene membrane surfaces using van der Waals interaction, without the need for any intermediate substances or special pre-treatment. The method allows for the rapid and clean preparation of graphene/polymer composite membranes, and is easy to scale up. By analyzing strain cracks in the graphene, the graphene-polyethylene interface shear strength was quantified as 9.52 MPa. The method also enables complex-surface transfer, simultaneous double-sided transfer, and facile patterning transfer, demonstrating its versatility.
Article
Physics, Multidisciplinary
T. S. Smith, F. Ming, D. G. Trabada, C. Gonzalez, D. Soler-Polo, F. Flores, J. Ortega, H. H. Weitering
PHYSICAL REVIEW LETTERS
(2020)
Article
Physics, Applied
Eduardo Machado-Charry, Cesar Gonzalez, Yannick J. Dappe, Laurence Magaud, Normand Mousseau, Pascal Pochet
APPLIED PHYSICS LETTERS
(2020)
Article
Nanoscience & Nanotechnology
Y. J. Dappe, Y. Almadori, M. T. Dau, C. Vergnaud, M. Jamet, C. Paillet, T. Journot, B. Hyot, P. Pochet, B. Grevin
Article
Nanoscience & Nanotechnology
Wei Zhang, Hanna Enriquez, Xuan Zhang, Andrew J. Mayne, Azzedine Bendounan, Yannick J. Dappe, Abdelkader Kara, Gerald Dujardin, Hamid Oughaddou
Article
Nanoscience & Nanotechnology
Khalid Quertite, Hanna Enriquez, Nicolas Trcera, Azzedine Bendounan, Andrew J. Mayne, Gerald Dujardin, Abdallah El Kenz, Abdelilah Benyoussef, Yannick J. Dappe, Abdelkader Kara, Hamid Oughaddou
Summary: This work investigates the electron-induced modification of NaCl thin film on Ag(110) surface. Electron beam bombardment causes desorption and formation of Cl vacancy defects on NaCl surface, which are observed using low energy electron diffraction and scanning tunneling microscopy. Auger electron spectroscopy confirms the effect of electron exposure on NaCl thin films, while density functional theory and STM simulation provide further confirmation. The presence of Cl vacancy leads to an increase in adhesion energy and charge transfer between NaCl film and Ag substrate.
Article
Physics, Condensed Matter
Fernando Flores, Diego Soler-Polo, Jose Ortega
Summary: This article discusses an alternative formulation of density functional theory (DFT) using orbital occupation numbers instead of electron density. By introducing effective potentials, a Kohn-Sham-like Hamiltonian is derived to account for electron-electron interactions. Furthermore, the description of Hartree and exchange energies, as well as the correlation energy and potentials, in terms of orbital occupation numbers is also discussed.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Physics, Multidisciplinary
F. Ming, X. Wu, C. Chen, K. D. Wang, P. Mai, T. A. Maier, J. Strockoz, J. W. F. Venderbos, C. Gonzalez, J. Ortega, S. Johnston, H. H. Weitering
Summary: Adatoms on a Si(111) substrate form a triangular lattice with unpaired electrons. Doping the Sn layer results in a superconducting state, which may exhibit chiral d-wave symmetry. Experiments confirm a doping-dependent critical temperature, fully gapped order parameter, time-reversal symmetry breaking, and enhanced zero-bias conductance near superconducting domain edges.
Article
Chemistry, Multidisciplinary
Julien Lavie, Van Binh Vu, Daniel Medina-Lopez, Yannick Dappe, Thomas Liu, Loic Rondin, Jean-Sebastien Lauret, Sylvain Latil, Stephane Campidelli
Summary: Carbon nanomaterials, such as fullerene, nanotubes, graphene, and graphene quantum dots (GQDs), have been extensively studied by the scientific community for over 30 years. The synthesis of GQDs can be achieved through top-down and bottom-up approaches, with the latter allowing better control over size and shape. In this study, rectangular-shaped GQDs containing up to 162 sp(2) carbon atoms were successfully synthesized without functionalization. The dispersion and optical properties of the GQDs were investigated using sodium deoxycholate surfactant in water. The larger GQDs showed better dispersibility, possibly due to the increased number of surfactant molecules on their surfaces.
HELVETICA CHIMICA ACTA
(2023)
Article
Nanoscience & Nanotechnology
Egzona Neziri, Wei Zhang, Alexander Smogunov, Andrew J. Mayne, Abdelkader Kara, Yannick J. Dappe, Hamid Oughaddou
Summary: We report on the structural properties of Bi on Au(110) using LEED, STM, and DFT calculations. Various reconstructions are observed at a Bi coverage lower than 1 ML, and we focus on the Bi/Au(110)-c(2 x 2) reconstruction (at 0.5 ML) and Bi/Au(110)-(3 x 3) structure (at 0.66 ML). We propose models for both structures based on STM measurements and confirm them further using DFT calculations.
Article
Chemistry, Multidisciplinary
Sergii Snegir, Yannick J. Dappe, Dmytro Sysoiev, Thomas Huhn, Elke Scheer
Summary: This study investigates the structure and properties of a self-assembled monolayer on highly oriented pyrolytic graphite using scanning tunneling microscopy. The results show that the triazatriangulenium cations form hexagonally packed structures driven by the interaction with the graphite lattice. The monolayer consists of TATA(+) with and without BF4- counterions. The cationic TATA(+) exhibits a higher appearance compared to the neutral TATA-BF4.
Article
Materials Science, Multidisciplinary
M. N. Nair, I. Palacio, A. Mascaraque, E. G. Michel, A. Taleb-Ibrahimi, A. Tejeda, C. Gonzalez, A. Martin-Rodero, J. Ortega, F. Flores
Summary: This study reports an experimental and theoretical investigation of the electron-phonon coupling in α-Sn/Ge(111). The results show the presence of a significant electron-phonon interaction in a specific phase of α-Sn/Ge(111), which may play a role in the formation of different phases at low temperatures.
Article
Chemistry, Physical
Anu Baby, Guillaume Marcaud, Yannick J. Dappe, Marie D'Angelo, Jean-Louis Cantin, Mathieu G. Silly, Guido Fratesi
Summary: This study investigates the adsorption behavior of phthalocyanine (H2Pc) molecules on the 6H-SiC(0001)-(3 x 3) surface, proposing a new adsorption model Si-phthalocyanine (SiPc) that is both energetically more stable and shows better agreement between experimental and simulated spectra, suggesting the potential for on-surface synthesis of SiPc molecules on this surface.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Shuhui Tao, Qian Zhang, Andrea Vezzoli, Cezhou Zhao, Chun Zhao, Simon J. Higgins, Alexander Smogunov, Yannick J. Dappe, Richard J. Nichols, Li Yang
Summary: In this study, the single-molecular conductance of a redox active viologen molecular bridge between Au|graphene electrodes was investigated in an electrochemical gating configuration. The results showed a clear off-on-off conductance switching behavior through gating of the redox state. The study also revealed that substituting one gold contact for a graphene one had a significant impact on the junction conductance values. The experimental data was compared against two theoretical models, providing insights into the charge state evolution of the molecule with electrode potential and the sequential charge transport through the redox center in the adiabatic limit. This work opens perspectives for graphene-based molecular transistors with more effective gating and a better understanding of electrochemical electron transfer at the single molecular level.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Shuhui Tao, Qian Zhang, Chunhui He, Xiangfei Lin, Ruochen Xie, Cezhou Zhao, Chun Zhao, Alexander Smogunov, Yannick J. Dappe, Richard J. Nichols, Li Yang
ACS APPLIED NANO MATERIALS
(2019)
Article
Materials Science, Multidisciplinary
Quentin Arnoux, Camille Blouzon, Dongzhe Li, Yannick J. Dappe, Alexander Smogunov, Pierre Bonville, Ludovic Tortech, Jean-Baptiste Moussy
