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Related papers: Adatom Diffusion at GaN (0001) and (000bar1) Surfa…

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Microscopic surface diffusivity theory based on atomic ionization energy concept is developed to explain the variations of the atomic and displacement polarizations with respect to the surface diffusion activation energy of adatoms in the…

Strongly Correlated Electrons · Physics 2009-07-09 Andrew Das Arulsamy , Kostya "Ken" Ostrikov

We determine atomic and electronic structure, formation energy, stability and magnetic properties of native point defects, such as Gallium (Ga) and Nitrogen (N) vacancies in bulk and at non-polar (10$\overline{1}$0) surface of wurtzite…

Materials Science · Physics 2017-12-15 Sanjay Nayak , Mit H. Naik , Manish Jain , U. V. Waghmare , S. M. Shivaprasad

We have investigated the initial growth of Fe on GaAs(110) by means of density functional theory. In contrast to the conventionally used (001)-surface the (110)-surface does not reconstruct. Therefore, a flat interface and small diffusion…

Materials Science · Physics 2009-09-01 A. Grünebohm , H. C. Herper , P. Entel

When two or more atoms bind to a solid surface, the substrate can mediate an interaction between them. In this paper, we use density-functional theory to quantify the substrate-mediated pair interaction between two adatoms on a…

Materials Science · Physics 2007-05-23 Kristen A. Fichthorn , Matthias Scheffler

Motivated by recent research of Nikitin et al. (J.Phys.D vol. 49, 055301(2009)), we examine the effects of interatomic interactions on adatom surface diffusion. By using a mean-field approach in the random walk problem, we derive a…

Statistical Mechanics · Physics 2011-05-17 Yuri B. Gaididei , Vadim M. Loktev , Anton G. Naumovets , Anatoly G. Zagorodny

We present direct evidence of enhanced Ga interdiffusion in InAs free-standing nanowires grown at moderate temperatures by molecular beam epitaxy on GaAs (111)B. Scanning electron microscopy together with X-ray diffraction measurements in…

Using density-functional theory with the local-density approximation and the generalized gradient approximation we compute the energy barriers for surface diffusion for Ag on Pt(111), Ag on one monolayer of Ag on Pt(111), and Ag on Ag(111).…

Materials Science · Physics 2009-10-30 C. Ratsch , A. P. Seitsonen , M. Scheffler

We present results for collective diffusion of adatoms on a stepped substrate with a submonolayer coverage. We study the combined effect of the additional binding at step edge, the Schwoebel barrier, the enhanced diffusion along step edges,…

Condensed Matter · Physics 2009-10-28 Juha Merikoski , See-Chen Ying

We investigate, both theoretically and experimentally, the drift, diffusion, and recombination of excitons in the strain field of an edge threading dislocation intersecting the GaN{0001} surface. We calculate and measure hyperspectral…

We determine the diffusion length of excess carriers in GaN by spatially resolved cathodoluminescence spectroscopy utilizing a single quantum well as carrier collector or carrier sink. Monochromatic intensity profiles across the quantum…

Thermal decomposition of wurtzite (0001)-oriented GaN was analyzed: in vacuum, under active N exposure, and during growth by rf-plasma assisted molecular beam epitaxy. The GaN decomposition rate was determined by measurements of the Ga…

Materials Science · Physics 2024-02-01 S. Fernández-Garrido , G. Koblmüller , E. Calleja , J. S. Speck

Using density-functional theory we compute the energy barriers and attempt frequencies for surface diffusion of Ag on Ag(111) with different lattice constants, and on an Ag adsorbate monolayer on Pt(111). We find that the attempt frequency…

Condensed Matter · Physics 2009-10-31 C. Ratsch , M. Scheffler

We present a first-principles analysis of the strain renormalization of the cation diffusivity on the GaAs(001) surface. For the example of In/GaAs(001)-c(4x4) it is shown that the binding of In is increased when the substrate lattice is…

Materials Science · Physics 2009-11-07 Evgeni Penev , Peter Kratzer , Matthias Scheffler

In a combined experimental and theoretical study, we investigate the influence of the material source arrangement in a molecular beam epitaxy (MBE) system on the growth of nanowire (NW) core-shell structures. In particular, we study the…

Applied Physics · Physics 2020-02-05 David van Treeck , Sergio Fernández-Garrido , Lutz Geelhaar

GaN based high electron mobility transistors show promise in numerous device applications which elicits the need for accurate models of bulk, surface, and interface electronic properties. We detail here a hybrid density functional theory…

Materials Science · Physics 2021-10-20 Eric Welch , Luisa Scolfaro

We study the growth of the Fe films on GaAs(100) at a low temperature, 140 K, by $in$-$situ$ UHV x-ray reflectivity using synchrotron radiation. We find rough surface with the growth exponent, $\beta_S$ = 0.51$\pm$0.04. This indicates that…

Materials Science · Physics 2007-05-23 T. C. Kim , J. -M. Lee , Y. Kim , D. Y. Noh , S. -J. OH , J. -S. Kim

This study is an optimization of GaAs and Al$_{0.55}$Ga$_{0.45}$As growth on GaAs (111)B substrates with a surface misorientation of 2{\deg} towards [$\bar{2}$11], aiming to enhance surface morphology. For quantum optical metasurfaces…

Materials Science · Physics 2025-03-04 T. Blaikie , M. C. Tam , S. Stich , M. Belkin , Z. R. Wasilewski

The minimum energy paths for the migration of interstitial Mg in wurtzite GaN are studied through density functional calculations. The study also comprises Li, Na, and Be dopants to examine the dependence on size and charge of the dopant…

Materials Science · Physics 2017-10-11 Giacomo Miceli , Alfredo Pasquarello

With the aim of investigating the possible integration of opto-electronic devices, epitaxial GaN layers have been grown on Si(111) SOI and on Si/CoSi2/Si(111) using metalorganic chemical vapor deposition. The samples are found to possess a…

Materials Science · Physics 2009-11-11 Shengqiang Zhou , A. Vantomme , B. S. Zhang , H. Yang , M. F. Wu

The determination of the carrier diffusion length of semiconductors such as GaN and GaAs by cathodoluminescence imaging requires accurate knowledge about the spatial distribution of generated carriers. To obtain the lateral distribution of…