Article
Chemistry, Physical
Jesse A. Johnson II, Ryan Need, David Brown, Chris Hatem, Bruce Adams, Xuebin Li, Kevin S. Jones
Summary: This study investigated the relaxation mechanism of Si1-xGex/Si heterostructures under pulsed laser melting and identified surface dislocation half-loops as the primary strain relieving defects. The findings have implications for understanding the potential applications of pulsed laser melting in pMOS source/drain contact engineering.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Lukas Wind, Masiar Sistani, Raphael Boeckle, Juergen Smoliner, Lada Vukusic, Johannes Aberl, Moritz Brehm, Peter Schweizer, Xavier Maeder, Johann Michler, Frank Fournel, Jean-Michel Hartmann, Walter M. Weber
Summary: This study reports on the systematic structural and electronic properties of Al-Si1-xGex heterostructures obtained through thermally induced exchange. The resulting junctions exhibit high structural quality with no intermetallic phases, and ultra-thin interfacial Si layers contribute to the morphologic stability. The findings provide a versatile platform with Si1-xGex composition-dependent properties, which can open up new device implementations for emerging nanoelectronic, optoelectronic, and quantum devices.
Article
Nanoscience & Nanotechnology
S. Xia, W. Zhang, Z. Yuan, J. Li, J. Ye, Y. Gu, Y. Miao, C. Li, Y. Deng, A. Shen, H. Lu, Y-F Chen
Summary: This study investigated the epitaxial growth of Si1-xGex thin films and observed a laminated relaxation process above a certain thickness, where the highly strained pseudomorphic layer could still be preserved even after relaxation. The anomalous relaxation phenomenon was attributed to a dislocation-driven relaxation mechanism, which could enhance the growth of highly mismatched heterostructure systems by manipulating dislocations.
MATERIALS TODAY NANO
(2021)
Article
Computer Science, Information Systems
Bamidele Ibrahim Adetunji, Andrew Supka, Marco Fornari, Arrigo Calzolari
Summary: This paper presents a high-throughput study of electron transport properties in Si1-xGex alloys, utilizing atomistic first principles calculations and statistical analysis. The results clarify the effects of Ge concentration and disorder on the properties of the Si1-xGex alloy, providing a set of Ge-dependent transport parameters for device modeling.
Article
Crystallography
A. V. Klekovkin, V. P. Martovitsky, V. A. Tsvetkov, E. A. Pershina
Summary: In Si(0 0 1)\(Si1-xGex 6-8 nm + Si 100-120 nm) x 2 (0.07 < x < 0.21) structures grown by MBE, X-ray reflectometry and diffraction were used to study the thickness variation. It was found that the second period thickness was smaller compared to the first period due to increasing misfit energy. Electron microscopy confirmed the smaller thickness of the second period. Three-waves diffraction on the forbidden reflection (002) showed different structural perfection values in two azimuthal directions. In the same sample, the reflectometry-determined average period was larger than the diffraction-determined period, and the angular distance between satellites on curves (002) corresponded to two different period values.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Engineering, Electrical & Electronic
Woohui Lee, Jehoon Lee, Deokjoon Eom, Joohee Oh, Changyu Park, Jinyong Kim, Hyungchul Shin, Hyoungsub Kim
Summary: We introduced Y-O bonds into the interfacial layer between HfO2 and Si1-xGex (x = 0, 0.15, and 0.3) to reduce the number of interfacial defects. Two different pretreatment methods involving cyclic pulses of Y(CpBut)3 and N2 were used, with or without an oxidizing agent (H2O) injection at 250 degrees C. The Y pretreatments were effective in reducing leakage current, positive flatband voltage shift, and interface state density induced by an increase in Ge concentration. However, both pretreatments increased the capacitance-equivalent oxide thickness, possibly due to a change in the composition of the interfacial layer.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Instruments & Instrumentation
A. Nelis, M. Chicoine, F. Schiettekatte, G. Terwagne
Summary: This study investigates the formation and crystallinity of Si1-xGex alloy films by ion implantation. The results show that germanium is mainly incorporated in substitutional sites in the crystal network, and the Si1-xGex layer is monocrystalline. Additionally, the experiment reveals that implantation at 600 degrees C leads to deeper Ge diffusion compared to ambient temperature implantation, but with a deteriorated crystallinity.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2023)
Article
Chemistry, Physical
Jaspinder Kaur, Rikmantra Basu, Ajay Kumar Sharma
Summary: This paper presents the design and implementation of a solar cell based on Si1-x-yGeySnx-Si1-xGex alloy, focusing on thickness reduction and conversion efficiency improvement. The structure shows better performance compared to previously reported Si1-xGex based solar cells, with high efficiency, smaller substrate thickness, and a 15% Ge composition. It is attractive for various applications in the solar cell industry.
Article
Materials Science, Multidisciplinary
Bhargab Deka, Ashis Kundu, Subhradip Ghosh, A. Srinivasan
Summary: X-ray diffraction studies on Ru2Fe(Si1-xGex) (0 <= x <= 1) alloys did not show the characteristic super-lattice peaks of the stable L2(1) structure for full Heusler alloys. The antiferromagnetic behavior in the alloy with x = 0 was attributed to the presence of B2 disorder. With increase in x, the alloys transitioned to ferromagnetic behavior due to improved L2(1) ordering. The comparison of experimental and theoretical properties provided insights into the magnetic interaction variations in the alloys.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Mingzhe Li, Baoxing Duan, Yintang Yang
Summary: The novel LDMOS device with silicon-germanium P-top layer and trench gate structure achieves ultra-low on-resistance and increased breakdown voltage, leading to high performance.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Fabio Isa, James P. Best, Anna Marzegalli, Marco Albani, Christophe Comte, Jamie J. Kruzic, Avi Bendavid
Summary: A novel approach is presented in this paper to tailor the stress properties of diamond thin films through boron doping and micro-fabrication of bridges using focused ion beam milling. Experimental data, supported by detailed confocal micro-Raman investigations and finite element method calculations, suggest that appropriate design of microbridge geometries, together with boron doping, can significantly enhance or diminish material stress compared to non-patterned thin films. This approach, combined with deterministic incorporation and positioning of diamond color centers, may offer new opportunities to tailor the optical and spin properties of diamond-based quantum devices through stress engineering.
Article
Materials Science, Multidisciplinary
Valentin Kovalev, Victor Thomas, Tatiana Setkova, Natalia Zubkova, Anna Spivak, Dmitry Fursenko, Vasiliy Yapaskurt, Alexander Antipin, Elena Borovikova
Summary: The hydrothermal synthesis of Be-2[(Si1-xGex)O-4] compound with a phenakite structure was successfully achieved at a temperature of 625 degrees C and a pressure of similar to 150 MPa in acidic alkaline-containing fluoride solutions. Be-2[(Si1-xGex)O-4] crystals with uniform and zonal structures were obtained using Li-containing and Na-containing mineralizers, respectively. The crystal growth rate and structure of Be-2[(Si1-xGex)O-4] were influenced by the germanium content, and a new Raman band was observed in the Ge-substituted phenakite crystals.
PHYSICS AND CHEMISTRY OF MINERALS
(2023)
Article
Engineering, Mechanical
Daoyun Chen, Qian Xiao, Minghui Mou, Wenbin Yang, Xinlong Liu, Yanjun Zeng
Summary: The fatigue reliability of heavy-haul locomotive car body underframe was evaluated using measured and virtual strain methods. The coupler load was calibrated through bench test and linear fitting. Key positions were monitored for acceleration responses and dynamic strains. Finite element analysis was conducted to obtain the load-strain transfer coefficients of the car body. Virtual strain was calculated by combining the obtained coefficients with measured coupler load and acceleration history. The fatigue damage and life of both measured and virtual strain under reliabilities of 95% and 97.7% were compared.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Chemistry, Multidisciplinary
Liubov Belyaeva, Cyril Ludwig, Yu-Cheng Lai, Chia-Ching Chou, Chih-Jen Shih
Summary: This study demonstrates a new approach to produce strain-free 2D monolayers at a macroscopic scale by using hydrogel substrates. These substrates overcome the limitations of previous methods and show superior uniformity and reproducibility. The extreme structural adaptability of hydrogel surfaces enables ultimate strain relaxation and uniformity in all types of 2D materials, regardless of their crystalline structure. The results suggest a universal strategy for attaining uniform and strain-free sheets of 2D materials and highlight the potential of interfacing them with soft matter.
Article
Engineering, Electrical & Electronic
Abhijit Kundu, Saunak Bhattacharya, Debraj Chakraborty, Sudipta Chakraborty, Moumita Mukherjee
Summary: This study presents the performance and prospects of strained Si/SiGe nano-scale photo-detectors in the infrared wavelength region, demonstrating improved photoelectric characteristics through the incorporation of Ge and the development of a novel four-array detector with higher responsivity and quantum efficiency.
IEEE TRANSACTIONS ON DEVICE AND MATERIALS RELIABILITY
(2021)
Article
Engineering, Electrical & Electronic
K. E. Siewierska, G. Atcheson, K. Borisov, M. Venkatesan, K. Rode, J. M. D. Coey
IEEE TRANSACTIONS ON MAGNETICS
(2017)
Article
Engineering, Electrical & Electronic
S. B. Porter, M. Venkatesan, P. Dunne, B. Doudin, K. Rode, J. M. D. Coey
IEEE TRANSACTIONS ON MAGNETICS
(2017)
Article
Materials Science, Multidisciplinary
F. Eskandari, S. B. Porter, M. Venkatesan, P. Kameli, K. Rode, J. M. D. Coey
PHYSICAL REVIEW MATERIALS
(2017)
Article
Physics, Multidisciplinary
C. Banerjee, K. Rode, G. Atcheson, S. Lenne, P. Stamenov, J. M. D. Coey, J. Besbas
Summary: The study investigated the all-optical reswitching phenomenon in a half-metallic Hensler ferrimagnet, Mn2Ru0.9Ga, analyzing the optimal time between two laser pulses and the physical mechanisms involved. The results indicate that spin waves generated through optical excitation can lead to transient parallel alignment of magnetic moments after a certain time.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Applied
Zexiang Hu, Jean Besbas, Ross Smith, Niclas Teichert, Gwenael Atcheson, Karsten Rode, Plamen Stamenov, J. M. D. Coey
Summary: Toggle switching behavior is observed in thin films of sperimagnetic amorphous DyxCo1-x and TbxCo1-x irradiated with single fast laser pulses. The films exhibit strong local random anisotropy, and subsequent laser pulses lead to partial re-switching of a decreasing amount of material, resulting in a granular structure. The toggle switching is attributed to the temperature-dependent ratio of local anisotropy to exchange.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
K. E. Siewierska, H. Kurt, B. Shortall, A. Jha, N. Teichert, G. Atcheson, M. Venkatesan, J. M. D. Coey, Z. Gercsi, K. Rode
Summary: The cubic Heusler alloy Ru2-xMn1+xAl, grown as a thin film on MgO and MgAl2O4 substrates, is a spin-polarised ferrimagnetic metal with weak magnetocrystalline anisotropy. Unlike Mn2RuxGa, it does not exhibit ferrimagnetic compensation or large magneto-galvanic effects, which are attributed to a combination of atomic order and hybridisation with the group 13 element Al or Ga. The spin polarisation is around 50% to 60%, with a gap in the density of states just above the Fermi level in fully ordered compounds.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Yangkun He, Simon Lenne, Zsolt Gercsi, Gwenael Atcheson, Jack O'Brien, Daniel Fruchart, Karsten Rode, J. M. D. Coey
Summary: This article investigates the spin structure of Mn4N films and its influence on the magnetotransport properties.
Article
Materials Science, Multidisciplinary
K. E. Siewierska, G. Atcheson, A. Jha, K. Esien, R. Smith, S. Lenne, N. Teichert, J. O'Brien, J. M. D. Coey, P. Stamenov, K. Rode
Summary: The ruthenium content in half-metallic Mn2RuxGa thin films plays a crucial role in determining their magnetic and electronic properties. The study reveals that chemical disorder exists for all compositions, and increasing Mn or Ru content affects the magnetic behavior and spin polarization. The systematic investigation of physical properties as a function of x and y could guide the selection of compositions for magnonic and spintronic MRG-based devices.
Article
Materials Science, Multidisciplinary
Rui Zhang, Zsolt Gercsi, M. Venkatesan, Karsten Rode, J. M. D. Coey
Summary: Calculations suggest that ordered Heusler alloys with 18 valance electrons could exhibit a variety of unusual electronic and magnetic states. Experimental results show that the as-cast alloys are all Pauli paramagnets with some degree of B2-type ordering, and prolonged annealing leads to phase segregation. Density functional theory calculations confirm that different atomic arrangements in the interpenetrating face-centered cubic sublattices could lead to unusual magnetic properties, but disorder destroys both magnetism and semiconductivity.
Article
Physics, Multidisciplinary
C. S. Davies, G. Bonfiglio, K. Rode, J. Besbas, C. Banerjee, P. Stamenov, J. M. D. Coey, A. Kimel, A. Kirilyuk
PHYSICAL REVIEW RESEARCH
(2020)
Article
Materials Science, Multidisciplinary
S. Sorokin, R. A. Gallardo, C. Fowley, K. Lenz, A. Titova, G. Y. P. Atcheson, G. Dennehy, K. Rode, J. Fassbender, J. Lindner, A. M. Deac
Article
Materials Science, Multidisciplinary
Roberto E. Troncoso, Karsten Rode, Plamen Stamenov, J. Michael D. Coey, Arne Brataas
Article
Physics, Applied
Kiril Borisov, Gwenael Atcheson, Gavin D'Arcy, Yong-Chang Lau, J. M. D. Coey, Karsten Rode
APPLIED PHYSICS LETTERS
(2017)
Article
Materials Science, Multidisciplinary
Davide Betto, Yong-Chang Lau, Kiril Borisov, Kurt Kummer, N. B. Brookes, Plamen Stamenov, J. M. D. Coey, Karsten Rode
Article
Materials Science, Multidisciplinary
Mario Zic, Karsten Rode, Naganivetha Thiyagarajah, Yong-Chang Lau, Davide Betto, J. M. D. Coey, Stefano Sanvito, Kerry J. O'Shea, Ciaran A. Ferguson, Donald A. MacLaren, Thomas Archer