The features of moiré pattern on electron-microscope images of free-standing quantum dots containing dislocations

Simulation of moiré pattern arising on plan-view transmission electron-microscope image of nanoisland (quantum dot) containing dislocations was performed on the base of finite-element method. The presence of dislocations with a screw component of Burgers vector in the nanoisland is shown to be energetically unfavourable. On the contrary, edge dislocations allow relieving mismatch stress most effectively. The simulation results provide a means to determine the type of dislocation inside quantum dot by the specific features of the moiré pattern on transmission electron microscope image. (paper)