Strain mapping at the atomic scale in highly mismatched heterointerfaces
Abstract
A complete characterization of dislocation network in a highly mismatched interface with high spatial resolution has been performed. The interface between InN quantum dots and a (0001) GaN substrate contains three noninteracting sets of regularly-spaced misfit dislocations lying along < 11 (2) over bar0 > directions. The network has a "Star of David" form, with each star bounding a hexagonal region which is pseudomorphic. These misfit dislocations form a threading dislocation network at the island edges due to free surface forces.