相关论文: Strain evolution in GaN Nanowires: from free-surfa…
Stranski-Krastanov strained islands undergo a shape anisotropy transition as they grow in size, finally evolving toward nanowires. This effect has been explained until now via simple energetic models that neglect thermodynamics. We…
Heterostructures of wurtzite based devices have attracted great research interests since the tremendous success of GaN in light emitting diodes (LED) industry. Among the possible heterostructure material candidates, high quality GaN thin…
High-shear methods have long been used in experiments to refine grain structures in metals, yet the underlying mechanisms remain elusive. We demonstrate a refinement process using molecular dynamic simulations of iron, wherein…
Crystal growth of semiconductor nanowires from a liquid droplet depends on the stability of this droplet at the liquid-solid interface. By combining in-situ transmission electron microscopy with theoretical analysis of the surface energies…
The fascinating realm of strain engineering and wetting transitions in two-dimensional (2D) materials takes place when placed on a two-dimensional array of nanopillars or one-dimensional rectangular grated substrates. Our investigation…
Scanning precession electron diffraction (SPED) is a powerful technique for investigating strain. While extensive literature exists analysing strain under high convergence angle conditions there are few systematic studies describing work…
In twisted bilayer graphene (TBG) devices, local strains frequently coexist and intertwine with the twist-angle-dependent moir\'e superlattice, significantly influencing the electronic properties of TBG, yet their combined effects remain…
Photonic or electronic confinement effects in nanostructures become significant when one of their dimension is in the 5-300 nm range. Improving their development requires the ability to study their structure - shape, strain field,…
We used density-functional theory based first principles simulations to study the effects of uniaxial strain and quantum confinement on the electronic properties of germanium nanowires along the [110] direction, such as the energy gap and…
Nanocrystalline metals with average grain sizes of only a few nanometers have recently been observed to fail through the formation of shear bands. Here, we investigate this phenomenon in nanocrystalline Ni which has had its grain structure…
We present detailed Raman studies of graphene deposited on gallium nitride nanowires with different variations in height. Our results show that different density and height of nanowires being in contact with graphene impact graphene…
The present study elucidates the correlation between the structural and optical properties of GaN nanowires grown on Si(111) substrate by plasma assisted molecular beam epitaxy (PA-MBE) technique under various growth conditions. GaN NWs…
When a material is subjected to an applied stress, the material will experience recoverable elastic deformation followed by permanent plastic deformation at the point when the applied stress exceeds the yield stress of the material.…
The relaxation dynamics of the contact angle between a viscous liquid and a smooth substrate is studied at the nanoscale. Through atomic force microscopy measurements of polystyrene nanostripes we monitor simultaneously the temporal…
In this paper we show how to link the electronic structures of two III-V systems, one a direct gap material, GaAs, and the other an indirect gap material, GaP, from their bulks right down to the shape of thin nanowires. GaAs and GaP bulk…
Confocal Raman spectroscopy is a versatile, non-invasive investigation tool and a major workhorse for graphene characterization. Here we show that the experimentally observed Raman 2D line width is a measure of nanometer-scale strain…
Gallium nitride (GaN), as a promising alternative semiconductor to silicon, is of well-established use in photoelectronic and electronic technology. However, the vulnerable GaN surface has been a critical restriction that hinders the…
Detailed high pressure Resonance Raman ($RR$) Spectroscopy and X-ray diffraction ($XRD$) studies are carried out on 3-4 layered $MoSe_2$ obtained by liquid exfoliation. Analysis of ambient $XRD$ pattern and $RR$ spectra indicate the…
Ga(In, Al)N alloys are used as an active layer or cladding layer in light emitting diodes and laser diodes. x-ray diffraction is extensively used to evaluate the crystalline quality, the chemical composition and the residual strain in…
Growth of mono-dispersed AlGaN nanowires of ternary wurtzite phase is reported using chemical vapour deposition technique in the vapour-liquid-solid process. The role of distribution of Au catalyst nanoparticles on the size and the shape of…