From compact point defects to extended structures in silicon
نویسنده
چکیده
First-principles studies of the formation and dynamics of silicon interstitial-clusters suggest a possible growth mechanism of silicon interstitial-chains as seen in macroscopic {311} planar defects. The relative populations of the three lowest-energy silicon tri-interstitials equilibrate within a few microseconds. Unfortunately, the tri-interstitial chain is unstable, quickly decaying to the ground-state interstitial. However, the four-interstitial chain with escape barriers of 0.54 eV is relatively stable and can be formed by exothermic capture of an interstitial by the ground-state tri-interstitial. This first successful step seems capable of growing longer chains. If one chain eases the formation of a second parallel chain, this may start the process of forming {311} planar defects. PACS. 61.72.Cc Kinetics of defect formation and annealing – 61.72.Ji Point defects (vacancies, interstitials) and defect clusters – 71.15.Mb Density functional theory, local density approximation, gradient and other corrections – 71.15.Pd Molecular dynamics calculations
منابع مشابه
Density Functional Theory Studies of Defects in the (5,5) Silicon Nanotube
We have performed density functional theory (DFT) calculations to investigate the properties of defect in arepresentative armchair model of silicon nanotubes (SiNTs). To this aim, the structures of pristine and defective(5,5) SiNTs have been optimized and the properties such as bond lengths, total energies, binding energies,.formation energies, gap energies, and dipole moments have been evaluat...
متن کاملComplexity of small silicon self-interstitial defects.
The combination of long-time, tight-binding molecular dynamics and real-time multiresolution analysis techniques reveals the complexity of small silicon interstitial defects. The stability of identified structures is confirmed by ab initio relaxations. The majority of structures were previously unknown, demonstrating the effectiveness of the approach. A new, spatially extended tri-interstitial ...
متن کاملSolutions of diffusion equation for point defects
An analytical solution of the equation describing diffusion of intrinsic point defects in semiconductor crystals has been obtained for a one-dimensional finite-length domain with the Robin-type boundary conditions. The distributions of point defects for different migration lengths of defects have been calculated. The exact analytical solution was used to verify the approximate numerical solutio...
متن کاملExtended RetroauricularTemporal Flap with Conchal Cartilage for Alar or Columellar Reconstruction
Abstract Background: The retroauricular-temporal or Washio flap has been introduced for reconstruction of partial nose and cheek defects, and has many advantages. We decided to evaluate the extended use of this technique in order to repair full thickness nasal defects. Methods: Superficial temporal and retroauricular arteries are identified with Doppler flowmetry. Selection points A, B, C and ...
متن کاملExtended Point Defect Structures at Intersections of Screw Dislocations in Si: A Molecular Dynamics Study
Molecular dynamics computer simulations have been employed with the Tersoff interatomic potential to examine the atomic structure of (a=2) h110i screw dislocations forming regular two-dimensional arrays in silicon. The main attention is focused on the atomic configurations of dislocation intersections. The dislocations are assumed to be undissociated, following HREM observations on the low-angl...
متن کامل