Sampling the diffusion paths of a neutral vacancy in Silicon with quantum mechanical calculations

Abstract

We report a first-principles study of vacancy-induced self-diffusion in crystalline silicon. Starting form a fully relaxed configuration with a neutral vacancy, we proceed to search for local diffusion paths. The diffusion of the vacancy proceeds by hops to first nearest neighbor with an energy barrier of 0.40 eV in agreement with experimental results. Competing mechanisms are identified, like the reorientation, and the recombination of dangling bonds by Wooten-Winer-Weaire process.