Eur. Phys. J. B 51, 195-208 (2006)
https://doi.org/10.1140/epjb/e2006-00215-9

Kinetic Monte Carlo and density functional study of hydrogen enhanced dislocation glide in silicon

¹ Department of Computer Sciences, University of Sheffield, Regent Court, 211 Portobello Road, Sheffield, S1 4DP, UK
² Institut des Matériaux Jean Rouxel, CNRS-Université de Nantes, UMR6502, B.P. 32229, 2 rue de la Houssinière, 44322 Nantes, France
³ Laboratoire de Physiques des Solides, Université Paris Sud, bâtiment 510, 91405 Orsay, France

Corresponding authors: ^a s.scarle@sheffield.ac.uk - ^b chris@ewels.info

Received: 22 November 2005
Revised: 28 February 2006
Published online: 2 June 2006

Abstract

We investigate Hydrogen Enhanced Dislocation Glide [HEDG], using n-fold way Kinetic Monte Carlo simulations of the interaction between hydrogen and 90° partial dislocations in silicon, and a range of new density functional calculations. We examine two different hydrogen arrival species, as well as hydrogen recombination at the dislocation. The Monte Carlo simulations use a line-wise description of the dislocation line parameterized using density functional calculations of migration and formation energies of various dislocation line defects and their complexes with hydrogen. From this we suggest that the rate of H₂ expulsion from the dislocation core increases as we approach HEDG, but that if the concentration of the hydrogen species goes beyond that required for HEDG it then slows dislocation motion by choking the line with defects comprised of two hydrogen atoms in a reconstruction bond. A `dislocation engine' model is proposed whereby hydrogen enters the dislocation line, catalyses motion, and is expelled along the core as H₂.