Stability and dynamics of frenkel pairs in Si

Extensive experiments and calculation have shown that interstitials in p-Si diffuse athermally, leading to the conclusion that vacancy-interstitial pairs, or Frenkel pairs (FPs), either rapidly recombine or dissociate, even at cryogenic temperatures. More recent experiments, however, suggest that FPs persist to 150 K. Here we report first-principles calculations of FP properties and resolve the apparent conflict between experiments by showing that athermal interstitial diffusion is suppressed in proximal FPs due to vacancy-interstitial interactions.