Observation of crystal dislocations in GaAs

Scanning tunneling microscopy was used to study the penetration of bulk dislocations on a {110} n-GaAs cleavage plane under ultrahigh vacuum conditions. Perfect and partial dislocations were imaged with atomic resolution for the As sublattice. From the atomically resolved images the Burgers vector and the slip plane of the dislocations can be directly determined. During the experiment the dislocations were found to be mobile over nanometer distances. No band bending was found around the dislocation cores, indicating that they are essentially electrically neutral in n-GaAs.