DISLOCATION ENERGY-BANDS IN GAAS - AN OPTICAL-ABSORPTION STUDY

Numerical expressions of the piezoelectric and deformation electric fields associated with dislocations in zinc-blende semiconductors are presented. They are used to calculate the optical absorption which they induce. These results are compared with the previously calculated charged-line field absorption. For GaAs, we find that the latter one is prevailing and that the deformation electric field can be always neglected. Application of this model to experimental results in GaAs lead us to propose a two dislocation energy band scheme. One dislocation energy band D1 is located above the valence band and the other D2 is near midgap.