Strong alignment of self-assembling InP quantum dots

We report on a mechanism for ordering of self-assembling InP quantum dots which are prepared by molecular-beam epitaxy on a strained ${\mathrm{In}}_{0.61}$ ${\mathrm{Ga}}_{0.39}$P buffer layer on (001) GaAs. A pronounced alignment of InP nanoscale clusters is observed along the 〈110〉 directions. This phenomenon is attributed to the diffusion of surface adatoms driven by the stress of misfit dislocations confined at the ${\mathrm{In}}_{0.61}$ ${\mathrm{Ga}}_{0.39}$P/GaAs interface. © 1996 The American Physical Society.