Lateral self-arrangement of self-assembled InAs quantum dots by an intentional-induced dislocation network

Abstract

We study the ordering of self-assembled InAs quantum dots (SAQD) along [1 1 0] and [ 1 ¯ 1 0 ] direction induced by a misfit dislocation network (MDN). The strained InGaAs buffer layer in which the MDN arises was adjusted in thickness and In content resulting in a high density of intentional misfit dislocations at a low surface roughness. Furthermore, we optimized the amount of InAs deposited for SAQD growth. AFM measurements testified an enhancement of SAQD generation at the misfit dislocation lines, leading to an alignment of quantum dots as chains with a length of at least 100 μm. By careful adjustment of the growth parameters of the SAQD, their formation between the chains is suppressed. Photoluminescence (PL) measurements reveal red shifted PL maxima of the aligned SAQD in comparison to the unordered ones.