Electro-plastic effect in semiconductors

The effects of passing a small current through a semiconductor on its indentation hardness, and the Dember effect at its surface, are reviewed. It is pointed out that these effects seem to be associated with charging of the surface states on the semiconductors. As these charged states decay, the current replenishes them. The charged surface states induce surface dipole layers, the electric fields of which modify the local energy band-gaps which in turn affects local dislocation mobilities; and hence, the indentation hardness.