Like-sign asymmetric dislocations in zinc-blende structure

Abstract

Symmetry considerations reveal that an asymmetry exists relative to orthogonal 60° dislocations of the same sign in zinc-blende structure. The effect of this asymmetry has been observed in compositionally graded crystals of In1−xGaxP and GaAs1−xPx grown from vapor phase. It is observed that the spatial arrangement of the two sets of misfit dislocations in an orthogonal array is different. In one 〈110〉 direction, the misfit dislocations tend to be uniformly distributed, while in the other 〈110〉 direction there is a marked tendency for periodic banding of the dislocations.