The diffusion (nt, mobility and lifetime of minority carriers in germanium containing parallel arrays of dislocations

Abstract

Abstract The presence of a high density of parallel edge dislocations in N-type germanium is found to significantly enhance the diffusion of holes in a direction parallel to the dislocations. The apparent diffusion constant is therefore anisotropic. In P-type germanium on the other hand the diffusion constant is isotropic and the carrier lifetime anisotropic. At high electric fields the drift mobility of boles in N-type germanium is found to be anisotropic with respect to the dislocation array, no comparable effect occurring in P-type material. These results can be explained by a model which assumes that dislocations introduce an additional acceptor level approximately intermediate in energy between the conduction and valence energy bands.