Enlightening the atomistic mechanisms driving self-diffusion of amorphous Si during annealing

TL;DR

This study investigates the atomic mechanisms of self-diffusion in amorphous silicon during annealing using molecular dynamics simulations, revealing different rearrangement mechanisms and migration energies influenced by structural defects.

Contribution

It provides new insights into the atomistic mechanisms and migration energies of self-diffusion in amorphous Si, considering different structural defect configurations.

Findings

Effective migration energy around 1 eV.

Higher diffusivities in samples with more coordination defects.

Similar migration energies across different structural types.

Abstract

We have analyzed the atomic rearrangements underlying self-diffusion in amorphous Si during annealing using tight-binding molecular dynamics simulations. Two types of amorphous samples with different structural features were used to analyze the influence of coordination defects. We have identified several types of atomic rearrangement mechanisms, and we have obtained an effective migration energy of around 1 eV. We found similar migration energies for both types of samples, but higher diffusivities in the one with a higher initial percentage of coordination defects.