Article
Chemistry, Physical
Yubin Kang, Fengyuan Lin, Jilong Tang, Qian Dai, Xiaobing Hou, Bingheng Meng, Dongyue Wang, Le Wang, Zhipeng Wei
Summary: In this study, GaAs/Ga(As)Sb/GaAs single quantum well nanowires were grown on Si(111) substrates by molecular beam epitaxy. The morphologies and tunable wavelengths of the nanowires were adjusted by interrupting the Ga droplets and changing growth conditions. The microstructure and crystal quality were characterized by various techniques, and the optical properties were studied using photoluminescence spectroscopy. This study provides a method to control the morphology, structure, and emission wavelength of quantum well or core-shell nanowires.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Biochemistry & Molecular Biology
Nikita Shandyba, Sergey Balakirev, Vladislav Sharov, Natalia Chernenko, Danil Kirichenko, Maxim Solodovnik
Summary: This paper presents experimental studies on the effect of Ga-focused ion beam (FIB) surface modification on Si(111) on the growth of GaAs nanowires (NWs). The authors observed three different modes of surface features on the GaAs NW growth based on the dose of Ga ions during surface modification. At low doses, NW growth is suppressed, while high-density GaAs NW arrays with a high fraction of vertically aligned nanowires are achieved at medium doses. At high doses, a continuous polycrystalline base with misoriented and thin GaAs NWs is formed. The interaction between the implanted Ga ions and the surface plays a key role in the modification and growth processes.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Multidisciplinary Sciences
Artur Tuktamyshev, Alexey Fedorov, Sergio Bietti, Stefano Vichi, Riccardo Tambone, Shiro Tsukamoto, Stefano Sanguinetti
Summary: Research has shown that the nucleation of Ga droplets on GaAs substrates exhibits a small critical cluster size and a high degree of spatial order in the droplet ensemble. At around 350°C, the droplet size distribution becomes bimodal, attributed to the interplay between the local environment and the limitation to adatom surface diffusion.
SCIENTIFIC REPORTS
(2021)
Article
Nanoscience & Nanotechnology
T. Dursap, M. Vettori, C. Botella, P. Regreny, N. Blanchard, M. Gendry, N. Chauvin, M. Bugnet, A. Danescu, J. Penuelas
Summary: This article presents a method to select and maintain the hexagonal wurtzite crystal phase in III-V semiconductor nanowires through molecular beam epitaxy, and successfully achieves the controlled growth of pure WZ phase by adjusting the V/III flux ratio. The potential benefits for electronics and opto-electronics applications are indicated by this successful controlled growth of WZ GaAs.
Article
Physics, Applied
Thomas Riedl, Vinay S. Kunnathully, Akshay K. Verma, Timo Langer, Dirk Reuter, Bjoern Bueker, Andreas Huetten, Joerg K. N. Lindner
Summary: A process for the large-area fabrication of nanopillar-patterned semiconductor templates for selective-area heteroepitaxy has been developed. The growth of defect-free nanoscale InAs islands on the nanopillar tops has been observed using electron microscopy.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
C. Zhu, C. Xu, P. Feng, X. Chen, G. M. de Arriba, J. Bai, T. Wang
Summary: This paper compares the growth and optical properties of InGaN/GaN MQWs grown on silicon substrates and sapphire substrates. It is found that the strain status of GaN has a significant influence on the growth and optical properties of InGaN/GaN MQWs, with significantly longer wavelength emission observed on the silicon substrate. Furthermore, it is revealed that the strain change on the silicon substrate is more sensitive to growth temperature change.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Francesco Tumino, Carlo Grazianetti, Christian Martella, Marina Ruggeri, Valeria Russo, Andrea Li Bassi, Alessandro Molle, Carlo S. Casari
Summary: The study investigates the MoS2/Ag heterostructure, observing a hexagonal moire ' pattern at the interface. Anomalous behavior of vibrational modes induced by the MoS2-Ag interaction is revealed in Raman spectroscopy. Exposure to ambient conditions leads to significant changes in Raman response and the formation of molybdenum oxysulfides.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Optics
Yongli Wang, Bojie Ma, Jian Li, Zhuoliang Liu, Chen Jiang, Chuanchuan Li, Hao Liu, Yidong Zhang, Yang Zhang, Qi Wang, Xinyu Xie, Xiaolang Qiu, Xiaomin Ren, Xin Wel
Summary: In this paper, a simple method is presented to reduce the threading dislocation density (TDD) by using a GaAs buffer, eliminating the need for complicated dislocation filter layers (DFLs) and intermediate buffer layers. A high-quality epitaxial GaAs film was grown on Si (001) by MOCVD, with a TDD of 9.4 x 10(6) cm(-2). InAs/GaAs QDs were grown on this GaAs/Si (001) virtual substrate by MBE, and a high-power QD laser was fabricated, achieving a room temperature continuous-wave output power of 138mW with a threshold current density of 397 A/cm(2) and a lasing wavelength of 1306 nm. This work proposes a simplified method for fabricating high-power QD lasers, which could promote the application of photonic integrated circuits.
Article
Chemistry, Physical
Nico Lovergine, Ilio Miccoli, Leander Tapfer, Paola Prete
Summary: The lattice tilt, mosaicity, and defect content of relaxed GaAs grown on exactly-oriented and 4 degrees-offcut (11 1)Si were investigated. Thin GaAs single-layers grown at 400°C and annealed at 700°C showed a density of surface pinholes. Double-layer samples were obtained by GaAs overgrowth at 700°C. The GaAs epilayers were tilted with respect to Si and rotational twins were observed in X-ray diffraction (XRD) pole figures.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Da Luo, Myeonggi Choe, Rafael A. Bizao, Meihui Wang, Haisheng Su, Ming Huang, Sunghwan Jin, Yunqing Li, Minhyeok Kim, Nicola M. Pugno, Bin Ren, Zonghoon Lee, Rodney S. Ruoff
Summary: A single-crystal graphene film grown on a Cu(111) foil by chemical vapor deposition (CVD) exhibits ribbon-like fold structures, which provide insights into the fracture strength and compression behavior of graphene.
ADVANCED MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Miriam Oliva, Timur Flissikowski, Michal Gora, Jonas Lahnemann, Jesus Herranz, Ryan B. Lewis, Oliver Marquardt, Manfred Ramsteiner, Lutz Geelhaar, Oliver Brandt
Summary: In this study, the spontaneous emission of zincblende GaAs/(Al,Ga)As core/shell nanowires was investigated using mu-photoluminescence spectroscopy. The results revealed the low degree of polytypism and high efficiency of these nanowires in terms of their internal quantum efficiency, extraction efficiency, and dependence on carrier density and temperature. Furthermore, the methodology established in this study can be applied to nanowires of other materials systems for optoelectronic applications.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Iuliia Dudko, Thomas Dursap, Anne D. Lamirand, Claude Botella, Philippe Regreny, Alexandre Danescu, Solene Brottet, Matthieu Bugnet, Sumeet Walia, Nicolas Chauvin, Jose Penuelas
Summary: This study demonstrates the growth of hexagonal Ge on self-assisted GaAs nanowires using molecular beam epitaxy without the use of gold catalyst. The hexagonal Ge maintains the crystal phase of the core, which is a significant finding for future development of photonic technologies.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Chemistry, Multidisciplinary
Young Ho Song, Doo Gun Kim, Dong Wook Lee, Jeong Woo Hwang, Parsian K. Mohseni, Jae Cheol Shin, Xiuling Li
Summary: This study demonstrates the direct heteroepitaxy of III-V nanowire arrays on silicon substrates. By fabricating a micrometer-scale SiNx pattern using photolithography technique, the diameter and height of the nanowires can be controlled effectively.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Physics, Multidisciplinary
Astrid Ali, Rubem Caetano, Jade Barreto, Guilherme Felix, Braulio Soares Archanjo, C. A. Achete, Fernando Stavale, Emilia Annese
Summary: In this study, MnO thin films grown on Cu(111) were investigated using various characterization techniques. The formation of oxidized Cu region at the interface and the influence of the Cu substrate on the properties of the MnO films were revealed through spectroscopic analysis.
Article
Multidisciplinary Sciences
Leila Balaghi, Si Shan, Ivan Fotev, Finn Moebus, Rakesh Rana, Tommaso Venanzi, Rene Hubner, Thomas Mikolajick, Harald Schneider, Manfred Helm, Alexej Pashkin, Emmanouil Dimakis
Summary: Semiconductor nanowires have potential for novel transistor concepts with higher electron mobility in strained coaxial nanowire heterostructures than in bulk crystals. Core/shell heterostructures, especially with a thick shell under strain, show significantly enhanced electron mobility compared to unstrained nanowires or bulk crystals, making strained gallium arsenide nanowires a unique candidate for advancing transistor technology.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Analytical
Robert B. Kohlhaas, Lars Liebermeister, Steffen Breuer, Marcel Amberg, David de Felipe, Simon Nellen, Martin Schell, Bjorn Globisch
Article
Physics, Applied
R. B. Kohlhaas, S. Breuer, L. Liebermeister, S. Nellen, M. Deumer, M. Schell, M. P. Semtsiv, W. T. Masselink, B. Globisch
APPLIED PHYSICS LETTERS
(2020)
Article
Materials Science, Multidisciplinary
K. Hlushko, A. Mackova, J. Zalesak, M. Burghammer, A. Davydok, C. Krywka, R. Daniel, J. Keckes, J. Todt
Summary: Ion irradiation induces localized relaxation of inplane compressive residual stresses in thin films by removing point defects from the crystal lattice, resulting in reduced strains of the 3rd order, as evidenced by decreased X-ray diffraction peak broadening and increased peak intensities. This study demonstrates that ion irradiation enables control over the residual stress state at distinct depths in the material.
Article
Multidisciplinary Sciences
Lars Liebermeister, Simon Nellen, Robert B. Kohlhaas, Sebastian Lauck, Milan Deumer, Steffen Breuer, Martin Schell, Bjoern Globisch
Summary: This paper introduces an opto-electronics-based, frequency-domain terahertz sensing technique that offers competitive measurement performance in a much simpler system. The method combines photomixing and time-delay technology, making it suitable for a wide range of applications in spectroscopy and industrial non-destructive testing.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Philipp Jordt, Stjepan B. Hrkac, Jorit Groettrup, Anton Davydok, Christina Krywka, Niklas Wolff, Lorenz Kienle, Rainer Adelung, Olaf M. Magnussen, Bridget M. Murphy
Summary: This study investigates the influence of crystalline structure on Schottky contact properties by examining three ZnO microrods. The results show that crystalline quality has a direct impact on Schottky contact properties, and an analytical model is created to determine the influence of stress. Rotation of strain orientation does not affect Schottky contact properties.
ADVANCED ENGINEERING MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Diletta Giuntini, Anton Davydok, Malte Blankenburg, Berta Domenech, Busra Bor, Mingjing Li, Ingo Scheider, Christina Krywka, Martin Mueller, Gerold A. Schneider
Summary: This study elucidates the load distribution and superlattice deformation mechanisms of cross-linked supercrystalline nanocomposites through in situ small- and wide-angle X-ray scattering combined with uniaxial pressing.
Article
Multidisciplinary Sciences
Kate L. M. Elder, W. Beck Andrews, Markus Ziehmer, Nadiia Mameka, Christoph Kirchlechner, Anton Davydok, Jean-Sebastien Micha, Alexander F. Chadwick, Erica T. Lilleodden, Katsuyo Thornton, Peter W. Voorhees
Summary: The study investigates the formation of grain boundaries during coarsening of nanoporous gold, with a focus on particle detachment and reattachment processes. The development of new grain boundaries is found to be highly dependent on the volume fraction and homogeneity of the nanostructure.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Engineering, Electrical & Electronic
Lars Liebermeister, Simon Nellen, Robert B. Kohlhaas, Sebastian Lauck, Milan Deumer, Steffen Breuer, Martin Schell, Bjorn Globisch
Summary: This study compared the performance of a state-of-the-art terahertz time domain spectroscopy (TDS) system and a novel optoelectronic frequency domain spectroscopy (FDS) system in layer thickness measurements, showing a factor of approximately two difference in accuracy between the two systems. While the TDS system achieved higher accuracy, the FDS system can be a competitive alternative due to its simpler architecture and potentially lower price.
JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
(2021)
Article
Optics
Milan Deumer, Steffen Breuer, Robert Kohlhaas, Simon Nellen, Lars Liebermeister, Sebastian Lauck, Martin Schell, Bjoern Globisch
Summary: The study presents photomixers made of iron doped indium gallium arsenide (InGaAs:Fe) as broadband receivers, demonstrating improved frequency response and lower noise levels. Record high values for cw THz spectroscopy were achieved along with increased dynamic range for frequencies above 1 THz. These improvements enable faster and more precise spectroscopy, benefiting industrial non-destructive testing.
Article
Polymer Science
Mathias K. Huss-Hansen, Erik G. Hedlund, Anton Davydok, Marie Hansteen, Jildert Overdijk, Gert de Cremer, Maarten Roeffaers, Matti Knaapila, Luigi Balzano
Summary: This study investigates the structural and morphological uniformity of high-performance gel-spun ultrahigh-molecular-weight polyethylene (UHMWPE) fibers using spatial resolutions of less than 2 μm. The findings reveal increased orientation of PE crystallites near the fiber surface, with the degree of orientation influenced by the draw down ratio and quench temperature. Polarized Raman spectroscopy and small-angle X-ray scattering computed tomography confirm the presence of a skin-core structure in the samples.
Article
Nanoscience & Nanotechnology
Tao Zhou, Gabriel Spartacus, Alexander Dahlstrom, R. Prasath Babu, Anton Davydok, Peter Hedstrom
Summary: To improve the mechanical properties of a high-performance tool steel, the alloy composition and heat treatment were redesigned using computational thermodynamics and kinetics in order to achieve fine dispersions of nanoscale precipitates. The designed chemistry and heat treatment were successfully implemented, resulting in a high number density of (V, Mo)C precipitates with an average diameter of about 5 nm after tempering the martensite at 600 degrees C for 2 h, as confirmed by advanced microstructural characterization and mechanical testing.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Olof Backe, Sebastian Kalbfleisch, Dirk Stiens, Thorsten Manns, Anton Davydok, Mats Halvarsson, Magnus Hornqvist Colliander
Summary: Recent progress in CVD technology has enabled the synthesis of metastable cubic Ti1-xAlxN coatings with high Al content. These coatings have unique micro-and nano-structures and exhibit exceptional hardness and resistance to wear and oxidation. The thermal stability and decomposition behavior of nano-lamellar CVD Ti0.2Al0.8N have been investigated, revealing the formation of hexagonal AlN (h-AlN) in the grain boundaries and a bulk transformation of the nano-lamellar structure at higher temperatures. The results provide insights into the complex decomposition processes in these metastable cubic coatings.
Article
Chemistry, Physical
Kritika Singh, Surya Snata Rout, Christina Krywka, Anton Davydok
Summary: This study analyzed lattice distortion and ion implantation in metallic micropillars prepared using plasma focus ion beam (PFIB) milling. Higher Xe ion energy led to higher density of implanted ions within the redeposited and milled material. Mixing of ions significantly influenced lattice structure, causing deformation in regions with higher ion concentrations.
Proceedings Paper
Engineering, Electrical & Electronic
Milan Deumer, Robert B. Kohlhaas, Steffen Breuer, Simon Nellen, Lauri Schwenson, Lars Liebermeister, Sebastian Lauck, Martin Schell, Bjoern Globisch
Summary: The study introduces continuous-wave terahertz (cw THz) detectors utilizing iron doped InGaAs as photoconductive material, showing improved properties over low-temperature grown InGaAs commonly used in modern cw THz detectors. Fabrication of photoconductive antennas on Fe-doped InGaAs achieved a bandwidth of 4.5 THz with a peak dynamic range of 112 dB in a coherent setup for the first time.
2021 46TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Robert B. Kohlhaas, Steffen Breuer, Sven Mutschall, Mathias Kehrt, Simon Nellen, Lars Liebermeister, Martin Schell, Bjoern Globisch
Summary: Improving photoconductive antennas and reducing absorption in InP:Fe substrate enabled a record bandwidth of 10 THz for a fiber-coupled THz time-domain spectrometer, showing a promising path towards ultrabroadband systems.
2021 46TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ)
(2021)
