Polarization Anisotropies in Strain-Free, Asymmetric, and Symmetric Quantum Dots Grown by Droplet Epitaxy

We provide an extensive and systematic investigation of exciton dynamics in droplet epitaxial quantum dots comparing the cases (311)A, (001), (111)A surfaces. Despite a similar s-shell structure common to three cases, absence wetting layer for (311)A samples leads larger carrier confinement compared where is present. This more pronounced dependence binding energies excitons on dot size strong anti-binding character positive-charged smaller dots. In-plane geometrical anisotropies (001) lead large electron-hole fine interaction (fine splitting (FSS) ∼100 μeV), whereas three-fold symmetric counterpart, this figure merit reduced by about one order magnitude. In all these we do not observe any splitting. Heavy-hole/light-hole mixing present studied leading broad spread linear polarization anisotropy (from 0 up 50%) irrespective surface orientation (symmetry confinement), splitting, nanostructure size. These results are important further development ideal single entangled photon sources based semiconductor