Dense arrays of site-controlled quantum dots with tailored emission wavelength: growth mechanisms and optical properties

We demonstrate the fabrication of arrayed, site-controlled pyramidal InGaAs/GaAs quantum dots (QDs) grown by metalorganic vapor phase epitaxy with tailored emission energy and periods as small as 200 nm, suitable for the integration with compact photonic structures. The observed variation of the QD emission energy with the geometric parameters of the array is attributed to adatom and precursor diffusion mechanisms during epitaxial growth. By adjusting the pattern geometry, the emission energy can be tuned over a wide range of ∼ 80 meV around 1.4 eV, with inhomogeneous broadening < 10 meV. Single photon emission of isolated QDs with g(2)X,X(0) = 0.11 is demonstrated, which attests to the suitability of these QDs for nanophotonic applications.