Article
Chemistry, Physical
Guang Yang, Jun-Shuai Chai, Kun Bu, Li-Fang Xu, Jian-Tao Wang
Summary: This study presents a systematic investigation of the structural, magnetic, and electronic properties of EuSi2 thin films on the Si(111) surface using ab initio calculations. The calculations show that the AA stacking structure is more favorable for EuSi2 thin films. The Eu2+ ions exhibit ferromagnetic coupling within each layer and antiferromagnetic coupling across adjacent silicene layers. The monolayer EuSi2 thin film is a semiconductor with an indirect surface band gap, while the multilayer EuSi2 thin films exhibit metallic behavior.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Materials Science, Coatings & Films
Shivani Varshney, Jun Nogami
Summary: Ultra-thin CsBr overlayers on the Ag (111) surface exhibit NaCl crystal structure instead of bulk CsBr structure in the first two atomic layers, with stability up to five monolayers and mobility up to 1.1nm thickness observed at room temperature. CsBr, a crucial component for growing CsPbBr3 perovskites, could provide valuable reference information for understanding the growth of CsPbBr3 perovskite thin films under similar conditions.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2021)
Article
Materials Science, Multidisciplinary
Shigemi Terakawa, Shinichiro Hatta, Hiroshi Okuyama, Tetsuya Aruga
Summary: We report on the formation of triple-atomic-layer metal films on Si(111) by depositing Mg onto In double-layer films. The (In, Mg) triple-layer phase exhibits a unique electronic structure, characterized by a circular Fermi surface composed of two circles with different radii.
Article
Chemistry, Physical
Jun-Shuai Chai, Guang Yang, Jing Xu, Wen-Wu Wang, Li-Fang Xu, Jian-Tao Wang
Summary: Through first-principles calculations, a stable R30 degree reconstruction of a Si-3 trimer bilayer on the Si(111) surface with a La coverage of 2/3 monolayer was identified. The unique honeycomb-like network structure formed by two Si-3 trimers and two La atoms on the surface unit cell is attributed to high structural stability, with distinct valence states of La2+ and La3+ present. Additionally, the system exhibits a semiconducting characteristic with a small surface band gap of 42 meV and shows good structural agreement with recent experimental observations in simulated STM images.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Inorganic & Nuclear
Martin Franz
Summary: The growth of organic films on silicon is a significant research field with both scientific and application importance. Phthalocyanines, a family of semiconducting molecules, are ideal candidates for modifying silicon surfaces due to their easily modifiable structure and properties. Various phthalocyanines on Si(111) surfaces have been studied in the past decades.
INORGANICA CHIMICA ACTA
(2024)
Article
Chemistry, Multidisciplinary
Abdur Rehman Jalil, Xiao Hou, Peter Schueffelgen, Jin Hee Bae, Elmar Neumann, Gregor Mussler, Lukasz Plucinski, Detlev Gruetzmacher
Summary: The growth of high-quality Bi thin-film allotropes on various substrates has been a challenge despite significant research efforts. This study presents a systematic growth investigation using molecular beam epitaxy to achieve high-quality Bi epilayers on Bi-terminated Si (111) 1 x 1 surfaces. The study provides a phase map of trigonal, orthorhombic, and pseudocubic thin-film allotropes of Bi and offers insights into phase segregation, stability, transformation, and thickness limitations through X-ray diffraction and transmission electron microscopy analysis.
Article
Materials Science, Multidisciplinary
Junji Yuhara, Hiroaki Muto, Masaaki Araidai, Masato Kobayashi, Akio Ohta, Seiichi Miyazaki, Sho-ichi Takakura, Masashi Nakatake, Guy Le Lay
Summary: In this study, single phase monolayer germanene has been successfully obtained on aluminum thin films using atomic segregation epitaxy, exhibiting unique structural characteristics that can be potentially explored for future research on its properties.
Article
Physics, Multidisciplinary
Chen Liu, Yinong Zhou, Guanyong Wang, Yin Yin, Can Li, Haili Huang, Dandan Guan, Yaoyi Li, Shiyong Wang, Hao Zheng, Canhua Liu, Yong Han, James W. Evans, Feng Liu, Jinfeng Jia
Summary: After depositing Bi on InSb(111)B, a Sierpifiski-triangle (ST)-like structure is observed in Bi thin films, which turns off the intrinsic electronic topology. The formation of ST-like islands is driven by the relaxation of a large misfit strain between the Bi adlayer and substrate. Besides a sufficiently large tensile strain, forming ST-like structures also requires larger adlayer-substrate and intra-adlayer elastic stiffnesses, and weaker intra-adlayer interatomic interactions.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Physical
Th. Schmidt, T. Wilkens, J. Falta
Summary: The adsorption and growth behavior of copper phthalocyanine (CuPc) on passivated Si(111) surfaces using different protecting agents (Ga, Bi, and Ag) has been studied. The studies have shown different structural and morphological evolution of CuPc films depending on the protecting agent used, with the best results obtained on Ag-terminated surfaces. The differences are explained in terms of interfacial interaction and occupied versus unoccupied local density of states.
Article
Chemistry, Multidisciplinary
Jie Xu, Changle Mu, Mingshu Chen
Summary: The metal-oxide interface is crucial in catalysis and understanding the structure and effect on catalytic performance of Cu-SiOx interface is challenging. In this study, ultrathin SiOx films were prepared and characterized to find that they can grow nearly layer-by-layer on the Cu(111) surface.
Article
Chemistry, Physical
Weiqu Chen, Zimin Chen, Zeqi Li, Zeyuan Fei, Yanli Pei, Gang Wang, Zhiyuan He
Summary: High quality epsilon-phase gallium oxide (Ga2O3) thin films have been successfully grown on silicon substrates using metal-organic chemical vapor deposition (MOCVD). The growth pressure is found to be an important parameter that affects the thin film quality.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Eric K. K. Abavare, Bright Kwakye-Awuah, Oswald A. Nunoo, Peter Amoako-Yirenkyire, G. Gebreyesus, Abu Yaya, Keshaw Singh
Summary: Total energy calculations were used to study the interface structures between SiC and Si, revealing that Si-Si interface is more favorable than Si-C interface. The electronic structure shows metallic character with electron transfer from SiC to Si.
CHEMICAL PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Zichao Li, Ye Yuan, Rene Hubner, Viktor Begeza, Thomas Naumann, Lars Rebohle, Olav Hellwig, Manfred Helm, Kornelius Nielsch, Slawomir Prucnal, Shengqiang Zhou
Summary: Researchers successfully prepared B20-MnSi films on Si(100) substrates, offering better conditions for practical applications. The regrown layer exhibits a higher Curie temperature compared to bulk material, and the magnetic skyrmion signature was confirmed through magnetic and transport measurements. Flash-lamp annealing in the millisecond range shows promise for fabricating Si-based skyrmionic devices.
MATERIALS TODAY PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Alberto Binetti, Wei-Fan Hsu, Koen Schouteden, Jin Won Seo, Jean-Pierre Locquet, Maria Recaman Payo
Summary: Vanadium sesquioxide (V2O3) is a promising material for new-generation sensors or smart devices due to its strong correlation effects and tunable metal-insulator transitions. The successful growth of epitaxial thin films on silicon substrates has been achieved by adjusting the growth conditions, and extensive characterization has been carried out. Structural analysis reveals the impact of temperature on thin film microstructures, and the lattice mismatch between silicon and V2O3 induces the growth of the corundum PI phase. Additionally, small deviations from stoichiometry significantly affect the resistivity change upon cooling.
RESULTS IN PHYSICS
(2023)
Article
Physics, Applied
John Hayden, Joseph Shepard, Jon-Paul Maria
Summary: Ferroelectric Al0.93B0.07N thin films were prepared on (100) Si substrates with the necessary c-axis out-of-plane orientation achieved through initial plasma treatment and subsequent layer growth. The resulting films exhibited strong polarization hysteresis, making them useful for integration with mainstream semiconductors.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Rawad K. Hallani, Bryan D. Paulsen, Anthony J. Petty, Rajendar Sheelamanthula, Maximilian Moser, Karl J. Thorley, Wonil Sohn, Reem B. Rashid, Achilleas Savva, Stefania Moro, Joseph P. Parker, Oscar Drury, Maryam Alsufyani, Marios Neophytou, Jan Kosco, Sahika Inal, Giovanni Costantini, Jonathan Rivnay, Iain McCulloch
Summary: A novel polymer pgBTTT was synthesized by changing the position of the glycol side chains, resulting in improved planarity and higher hole mobility compared to the original p(g2T-TT). Experimental data demonstrated that pgBTTT has advantages over p(g2T-TT) in terms of structural rigidity and hole mobility during operation.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Review
Physics, Condensed Matter
Benjamin Geisler, Petar Yordanov, Markus Ernst Gruner, Bernhard Keimer, Rossitza Pentcheva
Summary: By combining advanced growth and characterization techniques with first-principles simulations, recent advances in transition metal oxide films and superlattices as thermoelectric materials are discussed, focusing on quantum-scale approaches to tune their thermoelectric performance. The study shows that interface polarity and strain can achieve n- and p-type materials, and metal-to-insulator transitions induced by confinement and strain can lead to high Seebeck coefficients and power factors.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Toshiya Hamasaki, Kazuma Yagyu, Hisashi Mitani, Takashi Nishida, Hiroshi Tochihara, Takayuki Suzuki
Summary: Hydrogen etching of 4H-SiC(0001) surface at a moderate temperature was investigated to obtain a flat and clean surface for high-quality epitaxial graphene synthesis. After prolonged etching, scratches, depressions, and contaminations disappeared, and atomic steps appeared, maintaining the initial morphology. The optimum condition for flat and clean SiC surface was one hour of etching with a flow of 1.0 l/min, enabling the synthesis of zero layer graphene by thermal annealing in ultrahigh vacuum.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
(2021)
Article
Chemistry, Physical
Marco Turano, Marc Walker, Federico Grillo, Chiara Gattinoni, James Edmondson, Omar Adesida, Gregory Hunt, Paul Kirkman, Neville V. Richardson, Christopher J. Baddeley, Angelos Michaelides, Giovanni Costantini
Summary: This study investigates the adsorption mechanism of Benzotriazole (BTAH) on a copper surface, revealing different supramolecular structures formed at different molecular coverages and during annealing processes. The research sheds light on the strong molecule-substrate interaction and the formation of metal-organic complexes between copper adatoms and benzotriazolate species on the surface.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Harry Pinfold, Marco Sacchi, Graham Pattison, Giovanni Costantini
Summary: This study systematically investigates the interplay between halogen and hydrogen bonds in self-assembled monolayers, finding that in some systems, halogen bonds do not play a significant structural role while in others, effective cooperation between the two interactions is observed. The study provides valuable insight into the synergistic and competitive balance between halogen and hydrogen bonds in self-assembled monolayers, which is expected to be beneficial for the future design of monolayer systems using both types of interactions.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Philip J. Mousley, Luke A. Rochford, Paul T. P. Ryan, Philip Blowey, James Lawrence, David A. Duncan, Hadeel Hussain, Billal Sohail, Tien-Lin Lee, Gavin R. Bell, Giovanni Costantini, Reinhard J. Maurer, Christopher Nicklin, D. Phil Woodruff
Summary: Surface X-ray diffraction provides unambiguous structural information when studying the phenomenon of metal substrate adatom incorporation into molecular overlayers. Experimental evidence from scanning tunneling microscopy can be ambiguous and lacks quantitative information. The structural study of the Au(111)-F4TCNQ system shows agreement between experimental and theoretical data, providing insight into the height and conformation of the adsorbed molecule.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Paul Ryan, Philip James Blowey, Billal S. Sohail, Luke A. Rochford, David A. Duncan, Tien-Lin Lee, Peter Starrs, Giovanni Costantini, Reinhard J. Maurer, David Phillip Woodruff
Summary: A quantitative structural investigation was conducted to explore the incorporation of substrate adatoms into monolayers formed by strong molecular electron acceptors deposited onto metallic electrodes. The study found that TCNQ and F4TCNQ on Ag(100) represent ideal model systems lying at the boundary between these two possibilities. This behavior is consistent with adsorption energetics, indicating that the inclusion (or exclusion) of metal atoms into organic monolayers results from both thermodynamic and kinetic factors.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Physics, Condensed Matter
Armin Sahinovic, Benjamin Geisler
Summary: The study explores the sample efficiency for predicting vacancy layer formation energies and lattice parameters in different types of nitrides, oxides, and fluorides using a combination of density functional theory simulations and element-embedding neural networks. The neural networks model these properties with high precision and demonstrate the superiority of active learning over random training sets. By quantifying synergistic effects and analyzing material parallels using artificial intelligence, the study provides insights into transfer learning improvements and similarities/differences between various compound types.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Multidisciplinary
Adam Marks, Xingxing Chen, Ruiheng Wu, Reem B. Rashid, Wenlong Jin, Bryan D. Paulsen, Maximilian Moser, Xudong Ji, Sophie Griggs, Dilara Meli, Xiaocui Wu, Helen Bristow, Joseph Strzalka, Nicola Gasparini, Giovanni Costantini, Simone Fabiano, Jonathan Rivnay, Iain McCulloch
Summary: A series of fully fused lactam polymers with increased alkyl side chain content were synthesized via an inexpensive and non-toxic method. These polymers showed state-of-the-art n-type performance in organic electrochemical transistors (OECTs) and high thermoelectric performance when solution-doped.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Takayuki Suzuki, Kazuma Yagyu
Summary: We discovered that the 5 x 5 reconstruction on the Si(111)root 7 x root 3v -In surface is formed through indium deposition in a step-flow-like growth manner. This is different from the 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecule deposition on the root 7v x root 3v -rect surface that was previously known. The 5 x 5 reconstruction is an incommensurate structure and the similar to 5.4 x similar to 5.4 surface is considered unstable at room temperature.
Article
Materials Science, Multidisciplinary
Benjamin Geisler, Simon Follmann, Rossitza Pentcheva
Summary: Using density functional theory calculations, we investigated the formation of oxygen vacancies and their effects on the electronic and magnetic properties of LaNiO3 and superlattices. Our results show that epitaxial strain induces an anisotropy in the formation energy of oxygen vacancies. For the superlattice, the NiO2 layer is most prone to vacancy formation, while the AlO2 layer has the highest formation energies. Varying the vacancy concentration in the NiO2 layer leads to unexpected transitions and a magnetic phase transition. The interplay between electronic reconstructions and structural modifications induced by oxygen vacancies highlights the importance of explicit supercell treatment in understanding the complex response of transition metal oxides to defects.
Article
Materials Science, Multidisciplinary
P. Radhakrishnan, B. Geisler, K. Fuersich, D. Putzky, Y. Wang, G. Christiani, P. Wochner, P. A. van Aken, R. Pentcheva, E. Benckiser
Summary: The study investigates the relationship between crystal and electronic structure in YVO3-LaAlO3 superlattices using ab initio theory, scanning transmission electron microscopy, and x-ray diffraction, demonstrating how to reliably engineer orbital polarization.
Article
Physics, Multidisciplinary
Armin Sahinovic, Benjamin Geisler
Summary: By combining density functional theory simulations and active learning of neural networks, the study explores the formation energies of oxygen vacancy layers, lattice parameters, and their statistical correlations in different oxides. Neural networks are capable of predicting these observables with high precision, while active learning efficiently composes the training set, accelerating scans of large parameter spaces.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Materials Science, Multidisciplinary
James F. Ponder, Hu Chen, Alexander M. T. Luci, Stefania Moro, Marco Turano, Archie L. Hobson, Graham S. Collier, Luis M. A. Perdigao, Maximilian Moser, Weimin Zhang, Giovanni Costantini, John R. Reynolds, Iain McCulloch
Summary: The study evaluated the application of direct (hetero)arylation polymerization methods in the synthesis of conjugated polymers, demonstrating the production of highly regular and pure polymers. This method is simpler than other cross-coupling polymerization methods but performs comparably in organic thin-film transistors.
ACS MATERIALS LETTERS
(2021)
Article
Chemistry, Physical
Phillip Mark Rodger, Caroline Montgomery, Giovanni Costantini, Alison Rodger
Summary: The study revealed that diphenylalanine (FF) can self-assemble into stiff fibers with hollow tube morphology of varying widths, which show similar stabilities despite different diameters. Thermal stability analysis using linear dichroism spectroscopy showed that FF solutions are monomeric at 70 degrees C and begin to form fibers around 40 degrees C. The kinetics studies suggest a nucleation-driven assembly process with subsequent fiber growth, requiring a secondary nucleation process to explain the data.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
