Near-field imaging spectroscopy of low density InAs/InP quantum dots

Low-density InAs quantum dots (QDs) on an InP(001) substrate were grown by solid source molecular beam epitaxy applying both ripening process and double-cap method. Near-field imaging spectroscopy of these diluted QDs were performed at 10 K. We show this technique has ability to reveal the photoluminescence properties of each single QD. Furthermore, formation of three-dimensional nanostructures between QDs can be predicted in the QDs sample from our results.