InAs/GaAs(001) quantum dots grown by droplet epitaxy were investigated using electron microscopy. Misfit dislocations in relaxed InAs/GaAs(001) islands were found to be located approximately 2 nm above the crystalline sample surface, which provides an impression that the misfit dislocations did not form at the island/substrate interface. However, detailed microscopy data analysis indicates that the observation is in fact an artefact caused by the surface oxidation of the material that resulted in substrate surface moving down about 2 nm. As such, caution is needed in explaining the observed interfacial structure.
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http://dx.doi.org/10.1186/1556-276X-7-486 | DOI Listing |
ACS Appl Mater Interfaces
December 2024
National Renewable Energy Laboratory, Golden, Colorado 80401, United States.
The direct epitaxial growth of high-quality III-V semiconductors on Si is a challenging materials science problem with a number of applications in optoelectronic devices, such as solar cells and on-chip lasers. We report the reduction of dislocation density in GaAs solar cells grown directly on nanopatterned V-groove Si substrates by metal-organic vapor-phase epitaxy. Starting from a template of GaP on V-groove Si, we achieved a low threading dislocation density (TDD) of 3 × 10 cm in the GaAs by performing thermal cycle annealing of the GaAs followed by growth of InGaAs dislocation filter layers.
View Article and Find Full Text PDFNanotechnology
December 2024
School of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Nat Commun
December 2024
CAS Key Laboratory of Magnetic Materials and Devices, Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, China.
Soft-magnetic fibers (SMFs) play a crucial role in energy conversion, transmission, and storage within electronic devices. However, conventional SMFs have poor plasticity and are therefore difficult to withstand long-term tensile, torsional, and shear deformation. A high fraction of grain boundaries could improve plastic deformability of conventional SMFs, but deteriorates the coercivity.
View Article and Find Full Text PDFNano Lett
November 2024
Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India.
Van der Waals heteroepitaxy refers to the growth of strain- and misfit-dislocation-free epitaxial films on layered substrates or vice versa. Such heteroepitaxial technique can be utilized in developing flexible near-infrared transition metal nitride plasmonic materials to broaden their photonic and bioplasmonic applications, such as antifogging, smart windows, and bioimaging. Here, we show the first conclusive experimental demonstration of the van der Waals heteroepitaxy-enabled flexible semiconducting scandium nitride (ScN) thin films exhibiting near-infrared, low-loss epsilon-near-zero, and surface plasmon-polariton resonances.
View Article and Find Full Text PDFMaterials (Basel)
August 2024
School of Civil and Mechanical Engineering, Curtin University, Perth, WA 6845, Australia.
Ni/NiAl heterogeneous multilayer structures are widely used in aerospace manufacturing because of their unique coherent interfaces and excellent mechanical properties. Revealing the deformation mechanisms of interfacial structures is of great significance for microstructural design and their engineering applications. Thus, this work aims to establish the connection between the evolution of an interfacial misfit dislocation (IMD) network and tensile deformation mechanisms of Ni/NiAl multilayer structures.
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