Electronic Energy Levels of Dislocations in Silicon Calculated in the Effective Mass Approximation

The observed electronic effects due to dislocations in semiconductors have traditionally been ascribed to dangling bonds (1) or imperfections such as kinks. The lack of quantitative success of this tradition has prompted us to examine the possibility that electrons can be bound to a dislocation, or one of the partials of a dissociated dislocation, by the deformation potential associated with the strain field around the dislocation. The potential for this problem (in cylindrical coordinates) is of the form Vocos0/r. We have found comparable values for the lowest bound state of the effective-mass Schrodinger equation by two different methods, one of which leads to an upper bound. We compare our results with the spectroscopy of dislocation-related photoluminescence in silicon.