Hole recapture limited single photon generation from a single n -type charge-tunable quantum dot

The complete control of the electron occupation of a single InGaAs dot is shown to produce highly antibunched single photon emission with nonresonant optical excitation. Intensity correlation measurements show g(2) (0) values of 3% (50%) at low (high) excitation power. A distinct double peak structure is shown at time zero, demonstrating that although two photons may be emitted per excitation pulse, they are not simultaneously emitted. We interpret this feature as a hole recapture process from the wetting layer into the dot after initial recombination. The recapture dynamics is shown to be adjustable through engineering the valence potential. © 2008 American Institute of Physics.