相关论文: Mobility of dislocations in semiconductors
We investigate the physics of the core reconstruction and associated structural excitations (reconstruction defects and kinks) of dislocations in silicon, using a linear-scaling density-matrix technique. The two predominant dislocations…
Analysis is given of the changes of dislocation motion modes with stress and temperature variation. Different regimes of dislocation kink pair formation and spreading (motion in the random potential, in the field of random forces, the…
Theoretical calculations of the structure, formation and migration of kinks on a non-dissociated screw dislocation in silicon have been carried out using density functional theory calculations as well as calculations based on interatomic…
Kink defects in the 90-degree partial dislocation in silicon are studied using a linear-scaling density-matrix technique. The asymmetric core reconstruction plays a crucial role, generating at least four distinct kink species as well as…
The ability of a body-centered cubic metal to deform plastically is limited by the thermally activated glide motion of screw dislocations, which are line defects with a mobility exhibiting complex dependence on temperature, stress, and…
We compare the models that have been proposed in the literature for the atomic structure of the 90-degree partial dislocation in the homopolar semiconductors, silicon, diamond, and germanium. In particular, we examine the traditional…
We report an unexpected characteristic of dislocation cores in silicon. Using first-principles calculations, we show that all the stable core configurations for a non-dissociated 60$^\circ$ dislocation are sessile. The only glissile…
I present a theory of electron dynamics in semiconductors with slowly varying composition. I show that the frequency-dependent conductivity, required for the description of transport and optical properties, can be obtained from a knowledge…
The suitability of molecular statics (MS) simulations to model the structure of 90{\deg} glide set partial dislocation cores in GaAs is analyzed. In the MS simulations the atomic positions are iteratively relaxed by energy minimization, for…
In this work we study, theoretically, electronic mobility of the silicon carbide semiconductor in the 3C phase, named 3C-SiC. 3C-SiC has shown great potential for applications in extreme conditions. Thus, the study of the electronic…
In this paper the Boltzmann equation describing the carrier transport in a semiconductor is considered. A modified Chapman-Enskog method is used, in order to find approximate solutions in the weakly non-homogeneous case. These solutions…
Isolated kinks on thermally fluctuating (1/2)<111> screw, <100> edge and (1/2)<111> edge dislocations in bcc iron are simulated under zero stress conditions using molecular dynamics (MD). Kinks are seen to perform stochastic motion in a…
Plasticity in hexagonal close-packed zirconium is mainly controlled by the glide of dislocations with 1/3<1-210> Burgers vectors. As these dislocations cannot accommodate deformation in the [0001] direction , twinning or glide of <c+a>…
In this thesis a new model for calculating the total energy of atomic and solid systems is presented. The model is used to study the properties of the Si(100) surface and dislocation dynamics in the diamond structure. For the Si(100)…
Global optimization of transition paths in complex atomic scale systems is addressed in the context of misfit dislocation formation in a strained Ge film on Si(001). Such paths contain multiple intermediate minima connected by minimum…
Dislocations, line defects in crystalline materials, play an essential role in the mechanical[1,2], electrical[3], optical[4], thermal[5], and phase transition[6] properties of these materials. Dislocation motion, an important mechanism…
Point defects such as interstitial atoms are known to be attracted to screw dislocations. Understanding these interaction mechanisms is key to predicting the plasticity of real materials. Using a new machine learning interatomic potential…
The interplay of screw dislocations with carbon atoms is investigated in tungsten at high temperature using in situ straining experiments in a transmission electron microscope (TEM) and through ab initio calculations. When the temperature…
A multiscale approach based on molecular dynamics (MD) and kinetic Monte Carlo (kMC) methods is developed to simulate the dynamics of an $\langle \mathbf{a} \rangle$ screw dislocation in $\alpha$-Ti. The free energy barriers for the core…
We have combined the Boltzmann transport equation with an {\it ab initio} approach to compute the thermoelectric coefficients of semiconductors. Electron-phonon, ionized impurity, and electron-plasmon scattering rates have been taken into…