Hybrid semiconductor quantum dot-metal nanocrystal structures prepared by molecular beam epitaxy

We report the formation of In nanocrystals and their alignment near dilute InAs quantum dots (QDs) on GaAs (001) by molecular beam epitaxy. The In nanocrystals exhibit surface plasmon resonances in the near-infrared range, which can be matched with the emission wavelength of In(Ga)As QDs. The alignment of the In nanocrystals near the InAs QDs is due to the strain-driven migration yielding single isolated QD-metal nanocrystal pairs and isolated QD-metal nanocrystal dimer structures, representing the basic hybrid QD-metal nanocrystal plasmonic nanostructures.