Configuration of the misfit dislocation networks in uncapped and capped InN quantum dots

Abstract

A transmission electron microscopy study of the misfit dislocation (MD) networks between InN quantum dots (QDs) and GaN substrate/capping layer is presented. Applying the geometric phase algorithm in planar-view orientation, a complete characterization of the first interface shows a set of three families of 60° MDs lying along the three ⟨112¯0⟩ directions without node formation. The growth of a GaN capping layer decreases the plastic relaxation degree of the InN QDs by a rearrangement of the MDs. The full relaxation of the capping layer suggest that no changes will occur in the QD strain state during later growths.