Ordering of nanoscale InP islands on strain-modulated InGaP buffer layers

We report on strong alignment of self-assembled InP islands along the crystallographic [011]-directions. The islands are deposited on compressively strained InGaP buffer layers on (100) GaAs substrate by molecular beam epitaxy. The dot density is more than two orders of magnitude higher near the line-ups than in the region in between the lines. The dot arrangement strongly depends on the magnitude of the plastic strain. We observe a small density of misfit dislocations at the InGaP/GaAs interface coexisting with the coherently strained InP islands.