Related papers: Gallium interstitial contributions to diffusion in…
Diffusion mechanism of beryllium in gallium nitride was investigated by analyzing temperature-dependent diffusion profiles from an infinite source. Beryllium atoms were implanted into a high structural quality gallium nitride layer…
The semiconducting behaviour and optoelectronic response of gallium nitride is governed by point defect processes, which, despite many years of research, remain poorly understood. The key difficulty in the description of the dominant…
Convergence of density-functional supercell calculations for defect formation energies, charge transition levels, localized defect state properties, and defect atomic structure and relaxation is investigated using the arsenic split…
Using hybrid density functional theory, we address point defects susceptible to cause charge compensation upon Mg doping of GaN. We determine the free energy of formation of the nitrogen vacancy and of several Mg-related defects. The…
A roadblock in utilizing InGaAs for scaled-down electronic devices is its anomalous dopant diffusion behavior; specifically, existing models are not able to explain available experimental data on beryllium diffusion consistently. In this…
Irradiation of gallium arsenide (GaAs) produces immobile vacancies and mobile interstitials. However, after decades of experimental investigation, the immobile Ga vacancy eludes observation, raising the question: Where is the Ga vacancy?…
Ab initio molecular dynamics simulations are employed to investigate the dominant migration mechanism of the gallium vacancy in gaas as well as to assess its free energy of formation and the rate constant of gallium self-diffusion. our…
Ga interstitials in GaAs ($I_{Ga}$) are studied using the local-orbital {ab-initio} code SIESTA in a supercell of {216+1} atoms. Starting from eight different initial configurations, we find five metastable structures: the two tetrahedral…
Si-Ge interdiffusion with a high phosphorus doping level was investigated by both experiments and modeling. Ge/Si1-xGex/Ge multi-layer structures with 0.75<x_Ge<1 , a mid-10^18 to low-10^19 cm-3 P doping and a dislocation density of 10^8 to…
We calculate the diffusion barrier of fluorine adatoms on doped graphene in the diluted limit using Density Functional Theory. We found that the barrier $\Delta$ strongly depends on the magnitude and character of the graphene's doping…
Non-diffusive effects in charge transport become relevant as device sizes and features become comparable to the electronic mean free path. As a model system, we investigate the electric transport around mesoscopic defects in graphene with…
The mechanism underlying the long-range interstitial migration of nonequilibrium impurity interstitial species is used to simulate arsenic redistribution in ion implantation. An excellent agreement of the calculated arsenic concentration…
Crystallographic defects play a key role in determining the properties of crystalline materials. The new class of two-dimensional materials, foremost graphene, have enabled atomically resolved studies of defects, such as vacancies, grain…
Graphene supports strongly confined transverse-magnetic sheet plasmons whose spectral characteristics depend on the energetic distribution of Dirac particles. The question arises whether plasmons can become amplified when graphene is pumped…
We study the formation energies of native point defects in GaN through density-functional theory. In our first-principles scheme, the band edges are positioned in accord with hybrid density functional calculations, thus yielding a band-gap…
We report first-principles calculations that clarify the formation energies and charge transition levels of native point defects (Ga and O vacancies, interstitials, and a Ga vacancy-O vacancy pair) in corundum structured ${\alpha}$-Ga2O3.…
When in a pristine state, gallium and its alloys have the largest interfacial tensions of any liquid at room temperature. Nonetheless, applying as little as 0.8 V of electric potential across eutectic gallium indium (EGaIn) placed within…
The paper reports potassium diffusion measurements performed on gem-quality single-crystal alkali feldspar in the temperature range from $1169$ to $1021 \, \mbox{K}$. Natural sanidine from Volkesfeld, Germany was implanted with…
We find that Ag-interstitial ($Ag_I$) acts as an electron donor and plays an important role in Ag-excess doped polycrystalline PbTe thermoelectric materials. When Ag is heavily doped in PbTe, the neutral (Ag-Ag) dimer defect is formed at…
We have calculated formation energies and position of the defect levels for all native defects and for a variety of donor and acceptor impurities employing first-principles total-energy calculations. An analysis of the numerical results…