We have examined the regrowth rate of single implants of electrically active elements in silicon in terms of a model of crystallization that considers the diffusion of charged dangling bonds. An asymmetry in the regrowth velocity as a function of dopant concentration is explained in terms of differences in the shifts of the Fermi level on the amorphous (a‐) and crystalline (c‐) sides of thea‐cinterface. This effect is consistent with an increased shift in the Fermi level in thea‐ layer at thea‐cinterface. The increased shift is in turn suggested to be produced by an increased concentration of charged dangling bonds resulting from the dopant concentration gradient.