Article
Chemistry, Physical
Jaehun Jeong, Hyeon-Sik Kim, Gihyeon Kwon, Jeehong Park, Dasol Kim, Yeonjin Yi, Mann -Ho Cho
Summary: Positive charge-mediated phase modulation in MoTe2 has been studied using molecular beam epitaxy. The structural phase and stability of MoTe2 are influenced by the stoichiometric ratio of molybdenum to tellurium and the presence of tellurium adatoms. Positive charge doping by electron transfer to tellurium adatoms plays a crucial role in determining the phase and facilitates the practical application of phase transition.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Marcel S. Claro, Justyna Grzonka, Nicoleta Nicoara, Paulo J. Ferreira, Sascha Sadewasser
Summary: The 2D material beta-In2Se3 shows excellent material quality and device performance when grown on c-sapphire substrate, making it suitable for mass production of photodetectors.
ADVANCED OPTICAL MATERIALS
(2021)
Review
Chemistry, Multidisciplinary
Dechun Zhou, Heping Li, Nan Si, Hui Li, Harald Fuchs, Tianchao Niu
Summary: 2D materials have attracted attention for their unique properties since the discovery of graphene, with monoelemental 2D materials standing out for their superior synthetic exploration, excellent mobility, and wide range of band gaps. Efforts have been devoted to fabricating high-quality materials and revealing growth mechanisms in atomic scale.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Stefano Cecchi, Jamo Momand, Daniele Dragoni, Omar Abou El Kheir, Federico Fagiani, Dominik Kriegner, Christian Rinaldi, Fabrizio Arciprete, Vaclav Holy, Bart J. Kooi, Marco Bernasconi, Raffaella Calarco
Summary: This study presents an experimental and theoretical investigation of (GeTe)(m)(Sb2Te3)n films with a GeTe-rich composition. The films exhibit a tunable distribution of (GeTe)m(Sb2Te3)1 blocks of different sizes. The experimental evidence confirms the ferroelectric displacement in thick (GeTe)m(Sb2Te3)1 lamellae. Density functional theory calculations suggest the formation of a tilted (GeTe)m slab confined in GeTe-rich blocks, resulting in an unprecedented case between 2D and bulk ferroelectric materials. The ferroelectric behavior is confirmed by piezoresponse force microscopy and electroresistive measurements. The study demonstrates the resilience of the quasi van der Waals character of the films, regardless of their composition. Overall, this research presents a unique 2D platform that combines phase-change and ferroelectric switching properties, opening up possibilities for innovative device architectures.
Article
Chemistry, Multidisciplinary
Qi Chen, Kailai Yang, Bo Shi, Xiaoyan Yi, Junxi Wang, Jinmin Li, Zhiqiang Liu
Summary: Beyond traditional heteroepitaxy, 2D-materials-assisted epitaxy opens opportunities to revolutionize future material integration methods. However, basic principles in 2D-material-assisted nitrides' epitaxy remain unclear, which impedes understanding the essence, thus hindering its progress. Here, the crystallographic information of nitrides/2D material interface is theoretically established, which is further confirmed experimentally. It is found that the atomic interaction at the nitrides/2D material interface is related to the nature of underlying substrates. For single-crystalline substrates, the heterointerface behaves like a covalent one and the epilayer inherits the substrate's lattice. Meanwhile, for amorphous substrates, the heterointerface tends to be a van der Waals one and strongly relies on the properties of 2D materials. Therefore, modulated by graphene, the nitrides' epilayer is polycrystalline. In contrast, single-crystalline GaN films are successfully achieved on WS2. These results provide a suitable growth-front construction strategy for high-quality 2D-material-assisted nitrides' epitaxy. It also opens a pathway toward various semiconductors heterointegration.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Jae Whan Park, Jinwon Lee, Han Woong Yeom
Summary: This study identifies the atomic and electronic structures of various discommensuration domain walls in 1T-TaS2 quenched metastably with nanoscale domain wall networks through scanning tunneling microscope and density functional theory calculations. The domain walls exhibit different in-gap states, with metallic states appearing only in certain types of domain walls. This work provides insights for engineering the functionality of domain walls in correlated van der Waals materials.
NPJ QUANTUM MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Raphael T. Leriche, Alexandra Palacio-Morales, Marco Campetella, Cesare Tresca, Shunsuke Sasaki, Christophe Brun, Francois Debontridder, Pascal David, Imad Arfaoui, Ondrej Sofranko, Tomas Samuely, Geoffroy Kremer, Claude Monney, Thomas Jaouen, Laurent Cario, Matteo Calandra, Tristan Cren
Summary: Research shows that the misfit compound formed by sandwiching NbSe2 and LaSe layers behaves like a NbSe2 single layer, exhibiting great flexibility in doping and paving the way for the exploration of heavily doped 2D TMDs.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Runfa Feng, Wei Wang, Changhua Bao, Zichun Zhang, Fei Wang, Hongyun Zhang, Junjie Yao, Yong Xu, Pu Yu, Shuai-Hua Ji, Chen Si, Shuyun Zhou
Summary: This study reports the selective growth of monolayer TaTe2 films with different phases and superstructures by controlling the growth temperature and post-growth annealing treatment. The different electronic structures of 1H-TaTe2 and 1T-TaTe2 films are revealed through experimental measurements and theoretical calculations. The transition from a root 19x root 19 superstructure to a new 2 x 2 superstructure is observed in the annealed 1H-TaTe2 film.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Han Xiao, Wenzhuo Zhuang, Leyi Loh, Tao Liang, Anabil Gayen, Peng Ye, Michel Bosman, Goki Eda, Xuefeng Wang, Mingsheng Xu
Summary: This work demonstrates the van der Waals epitaxial growth of air-stable 2D magnetic CrS2 on mica substrate by chemical vapor deposition (CVD). The CrS2 crystallites exhibit a metallic behavior with a moderate conductivity and room-temperature ferromagnetism. The results offer a new platform for further research and spintronic device applications.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Hao Wang, Yao Wen, Xiaoxu Zhao, Ruiqing Cheng, Lei Yin, Baoxing Zhai, Jian Jiang, Zhongwei Li, Chuansheng Liu, Fengcheng Wu, Jun He
Summary: The heteroepitaxial growth of ferromagnetic CuCr2Te4 nanosheets on Cr2Te3 and mica by chemical vapor deposition is reported. The CuCr2Te4 nanosheets on mica exhibit thickness-dependent ferromagnetism with a decrease in Curie temperature (T-C) and an enhancement of perpendicular magnetic anisotropy. Moreover, the lattice-matched heteroepitaxial ultrathin CuCr2Te4 on Cr2Te3 shows an enhanced robust ferromagnetism with an increased T-C due to interfacial charge transfer. This work provides a method to construct robust room-temperature 2D magnetic heterostructures for functional spintronic devices.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Xinjian Wei, Congkuan Tian, Hang Cui, Yongkai Li, Shaobo Liu, Ya Feng, Jian Cui, Yuanjun Song, Zhiwei Wang, Jian-Hao Chen
Summary: This study reports the observation of LMR in layered kagome superconductor and CDW material, as well as the dimensional and temperature crossovers of such LMR. The possible origin of the LMR is attributed to two-dimensional CDW fluctuations. These findings provide a new perspective for understanding the interactions between competing orders in kagome superconductors.
Article
Physics, Multidisciplinary
Yaning Cui, Tianhao Su, Lei Qiao, Zongquan Gu, Gianni Profeta, Alessandra Continenza, Wei Ren
Summary: We conducted an ab-initio study on monolayer BaBiO3 to explore the suppression of charge density wave (CDW) phase and the insulator-metal transition. By applying an electric field and charge doping, we found that the metallic phase can be stabilized, the CDW phase can be destroyed, and a metallic metastable phase can be induced. Furthermore, hole doping was also effective in suppressing the CDW phase and promoting a metallic phase with strong electron-phonon coupling, suggesting the possibility of achieving superconductivity. BaBiO3 in low dimensions demonstrates great flexibility in its electronic properties, which can be controlled by external tools such as electric fields and charge doping.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2023)
Review
Chemistry, Multidisciplinary
Zhihong Zhang, Xiaonan Yang, Kaihui Liu, Rongming Wang
Summary: Two-dimensional (2D) materials with special crystal structure exhibit unique properties, making them promising in fields such as electronics and optoelectronics. To realize their applications, especially in integrated devices, the growth of large-size single crystals is necessary. Epitaxy, specifically the growth of 2D materials with specific orientations on single-crystal substrates, is the most feasible way to achieve this. The lattice symmetry relation and interaction between 2D materials and the substrate determine the epitaxy behaviors, which are systematically discussed in this article. Opportunities and challenges for the epitaxy of 2D single crystals in the future are summarized.
Article
Chemistry, Physical
Jose D. Gouveia, Gerard Novell-Leruth, Francesc Vin, Francesc Illas, Jose R. B. Gomes
Summary: MXenes, a newly discovered class of two-dimensional materials, show promising potential for biomedical and electronic applications. First-principles calculations on the titanium carbide MXene surface reveal physisorption as the dominant mechanism for nucleobases, with molecules sitting parallel to the surface at a distance of about 2.5A. The moderate adsorption energies and van der Waals interactions suggest the Ti2CO2 MXene's suitability as a nucleobase sensor.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Yande Que, Yang-Hao Chan, Junxiang Jia, Anirban Das, Zhengjue Tong, Yu-Tzu Chang, Zhenhao Cui, Amit Kumar, Gagandeep Singh, Shantanu Mukherjee, Hsin Lin, Bent Weber
Summary: Atomic monolayers of tungsten ditelluride (WTe2) exhibit a 2D topological excitonic insulator state, and the 2D bulk energy gap can be tuned by gate voltage, providing a novel way to control non-trivial 2D superconductivity with excitonic pairing.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Evangelia Xenogiannopoulou, Dimitra Tsoutsou, Polychronis Tsipas, Sotirios Fragkos, Stefanos Chaitoglou, Nikolaos Kelaidis, Athanasios Dimoulas
Summary: In this study, bismuth films were successfully grown by molecular beam epitaxy on a 2D-HfTe2 template. The transition from pseudocubic Bi(110) and hexagonal Bi(111) phases to pure hexagonal Bi(111) was observed as the number of bilayers increased. The electronic band structure of the grown Bi(111) films matched well with density functional theory calculations. The stability of the capped Bi(111) thin film under ambient conditions was confirmed through X-ray photoelectron spectroscopy and Raman spectroscopy.
Article
Materials Science, Multidisciplinary
E. Rongione, S. Fragkos, L. Baringthon, J. Hawecker, E. Xenogiannopoulou, P. Tsipas, C. Song, M. Micica, J. Mangeney, J. Tignon, T. Boulier, N. Reyren, R. Lebrun, P. Le Fevre, S. Dhillon, A. Dimoulas, H. Jaffres, M. George
Summary: This study demonstrates sizable terahertz (THz) emission through a nanometric thick topological insulator (TI)/ferromagnetic junction. By employing terahertz emission time domain spectroscopy (TDS), the contribution of topological surface states (TSS) to spin-to-charge conversion (SCC) is investigated, highlighting the significance of this approach for studying interfacial spintronic properties.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Physics, Applied
Sotirios Fragkos, Panagiotis Pappas, Evgenia Symeonidou, Yerassimos Panayiotatos, Athanasios Dimoulas
Summary: In this study, the generation and annihilation of magnetic skyrmions in two-dimensional van der Waals materials were theoretically demonstrated. Through temperature and field control, the velocity and direction of the skyrmions can be manipulated using ultra-low current densities and temperature, providing new insights for the control and design of magnetic skyrmions in two-dimensional van der Waals heterostructures.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Azhar Fakharuddin, Konstantina-Kalliopi Armadorou, Leandros P. Zorba, Marinos Tountas, Tobias Seewald, Anastasia Soultati, Polychronis Tsipas, Emilia R. Schuetz, Nikolaos Tzoganakis, Stylianos Panagiotakis, Konstantina Yannakopoulou, Athanasios Dimoulas, Vassilis Psycharis, Emmanuel Kymakis, Abd Rashid bin Mohd Yusoff, Konstantinos Aidinis, Lukas Schmidt-Mende, Georgios C. Vougioukalakis, Mohammad Khaja Nazeeruddin, Maria Vasilopoulou
Summary: Inverted perovskite solar cells (PSCs) have gained attention due to their low-temperature fabrication process. However, the limited availability of electron transport materials, particularly the commonly used PCBM, compromises the efficiency and stability of the cells. In this study, a new electron transport material called EPF03 was synthesized and tested in inverted PSCs, showing a significant improvement in efficiency compared to PCBM. The results also suggest that EPF03 can enhance the stability and photostability of perovskite solar cells.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Crystallography
Haonan Tang, Sergej Pasko, Simonas Krotkus, Thorsten Anders, Cornelia Wockel, Jan Mischke, Xiaochen Wang, Ben Conran, Clifford McAleese, Ken Teo, Sreetama Banerjee, Henry Medina Silva, Pierre Morin, Inge Asselberghs, Amir Ghiami, Annika Grundmann, Songyao Tang, Hleb Fiadziushkin, Holger Kalisch, Andrei Vescan, Salim El Kazzi, Alain Marty, Djordje Dosenovic, Hanako Okuno, Lucie Le Van-Jodin, Michael Heuken
Summary: The nucleation and coalescence behavior of WS2 crystallites and films grown on sapphire substrates were studied using MOCVD. The nucleation temperature and substrate annealing conditions were found to influence the size of WS2 domains, with higher temperatures promoting larger domain sizes. The surface coverage and coalescence behavior of WS2 domains were dependent on growth duration, allowing the production of monolayer films with low bilayer content. The crystalline quality of the coalesced films was evaluated, showing slight misorientation of crystallites in the WS2 monolayer. The electrical performance of the films was also assessed, demonstrating high mobility values and a high Ion/Ioff ratio.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Chemistry, Multidisciplinary
E. Georgopoulou-Kotsaki, P. Pappas, A. Lintzeris, P. Tsipas, S. Fragkos, A. Markou, C. Felser, E. Longo, M. Fanciulli, R. Mantovan, F. Mahfouzi, N. Kioussis, A. Dimoulas
Summary: The 2D van der Waals ferromagnetic metals FexGeTe2 with x = 3-5 have attracted significant attention. In this study, epitaxial Fe5-dGeTe2 (FGT) heterostructures were grown on insulating crystalline substrates using Molecular Beam Epitaxy (MBE). The addition of Bi2Te3 topological insulator (TI) to FGT films significantly enhanced the saturation magnetization and Curie temperature (Tc), with record values of 570 K obtained.
Article
Physics, Applied
N. Figueiredo-Prestes, P. Tsipas, S. Krishnia, P. Pappas, J. Peiro, S. Fragkos, V. Zatko, A. Lintzeris, B. Dlubak, S. Chaitoglou, M. Heuken, N. Reyren, H. Jaffres, P. Seneor, A. Dimoulas, J. M. George
Summary: With the development of technologies utilizing quantum phenomena, research on alternative materials and heterostructure engineering has been opened up. This study focuses on the magnetotransport properties of TI/2D-FM heterostructures composed of Cr1+delta Te2/Bi2Te3 stacks grown by molecular-beam epitaxy. The results reveal high levels of effective torques, interfacial magnetoresistance effects, and anomalies in the anomalous Hall effect. The relevance of the TI/2D-FM interface and the preservation of polarized surface states are demonstrated.
PHYSICAL REVIEW APPLIED
(2023)
Article
Chemistry, Physical
Maria-Athina Apostolaki, Elias Sakellis, Polychronis Tsipas, Maria Giannouri, Spiros Gardelis, Nikos Boukos, Athanasios Dimoulas, Vlassis Likodimos
Summary: Heterostructured WO3/TiO2 photonic crystal films in the form of three-dimensional macroporous inverse opals were developed by single-step, three-phase co-assembly of colloidal templates with water soluble precursors. The properties of the inverse opals could be controlled by adjusting the W/Ti molar ratio and macropore diameter. This method provides a promising route for the development of heterostructured inverse opal networks with tailored electronic properties and improved solar light harvesting.
APPLIED SURFACE SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Martha Pylarinou, Elias Sakellis, Polychronis Tsipas, George Em. Romanos, Spiros Gardelis, Athanasios Dimoulas, Vlassis Likodimos
Summary: Homojunction engineering between Mo- and Ca-doped BiVO4 nanocrystals in the skeleton of photonic band gap engineered inverse opals is introduced as a strategy to improve the efficiency of nanostructured metal oxide photocatalysts. The nanostructured homojunction Mo-BiVO4/Ca-BiVO4 photonic films outperformed their individual constituents in photocurrent generation and photocatalytic degradation rate under visible light, showing great potential for water remediation by pharmaceutical micropollutants.
ACS APPLIED NANO MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Eleftherios Christopoulos, Mohamed M. Elsenety, Andreas Kaltzoglou, Constantinos C. Stoumpos, Mattia Gaboardi, Jasper R. Plaisier, Polychronis Tsipas, Elias Stathatos, Evangelos G. Vitoratos, Athanasios Dimoulas, Polycarpos Falaras
Summary: This study explores the use of the ionic liquid 1-hexyl-3-methylimidazolium iodide (HMImI) for the synthesis of a lead halide derivative, (HMIm)PbI3, which enhances the efficiency and stability of perovskite solar cells. The (HMIm)PbI3 compound forms 1D chains and acts as a semiconductor with a band gap of 2.85 eV. When deposited on top of the main perovskite absorber, it improves the radiative recombination and open circuit voltage by reducing trap state density, while preventing humidity penetration and ion migration.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Emanuele Longo, Lorenzo Locatelli, Polychronis Tsipas, Akylas Lintzeris, Athanasios Dimoulas, Marco Fanciulli, Massimo Longo, Roberto Mantovan
Summary: Properly tuning the Fermi level position in topological insulators is crucial for tailoring their spin-polarized electronic transport and improving device efficiency. In this study, a highly crystalline Bi2Te3/Sb2Te3 heterostructure was successfully grown on large area Si(111) substrates using in situ metal organic chemical vapor deposition. The surface Fermi level of Bi2Te3 was effectively tuned by growing it on top of Sb2Te3. A spin-charge converter based on this heterostructure was fabricated and its performance was verified through spin pumping ferromagnetic resonance. The results demonstrate the successful tuning of the surface Fermi level and have potential implications for future technology transfer.
ACS APPLIED MATERIALS & INTERFACES
(2023)
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
Chemistry, Multidisciplinary
Emigdio Chavez-Angel, Polychronis Tsipas, Peng Xiao, Mohammad Taghi Ahmadi, Abdalghani H. S. Daaoub, Hatef Sadeghi, Clivia M. Sotomayor M. Torres, Athanasios Dimoulas, Alexandros El Sachat
Summary: Using van der Waals epitaxy, we engineered highly insulating thermal metamaterials based on atomically thin lattice-mismatched Bi2Se3/MoSe2 superlattices and graphene/PdSe2 heterostructures, offering exceptional thermal resistances and ultralow cross-plane thermal conductivities comparable to those of amorphous materials. Experimental data supported by calculations reveal the impact of lattice mismatch, phonon-interface scattering, size effects, temperature, and interface thermal resistance on cross-plane heat dissipation, providing valuable insights into thermal transport characteristics and synthetic methods for large-area van der Waals films.
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)
