Patterning of confined-state energies in site-controlled semiconductor quantum dots

We demonstrate control of the confined-state energies of semiconductor quantum dots (QDs) grown on prepatterned substrates. The InGaAsAlGaAs QDs self-order at the apex of self-limiting, inverted pyramids whose locations are fixed by lithography. The confinement energy in the dots is systematically varied across the substrate by changing the pattern of the pyramid array in their vicinity. The resulting energy- and site-controlled QDs show systematic and reproducible shifts of their emission wavelengths as well as antibunched photon emissions from confined single excitons. Such QDs should be useful for applications in quantum information processing and quantum communication devices, e.g., multiple-wavelength single-photon emitters.