Exciton complexes in individual quantum dots as a single-photon source

We investigate the photon emission statistics of recombination processes of different exciton complexes confined in a single photo-excited semiconductor quantum dot. The complexes are identified by the photoluminescence spectrum of the dot, which shows a rich line structure due to the various combinations of electrons and holes that can be confined in the dot. We demonstrate single-photon emission from each of these exciton complexes, revealing the biexciton state to produce single photons with significantly less jitter in their emission time than the single exciton.