Three-photon cascade from single self-assembled InP quantum dots

Abstract

We present photon correlation measurements performed on single self-assembled InP quantum dots in a GaInP barrier. Correlation measurements done under continuous excitation reveal a pronounced antibunching dip for the emission from the single exciton, the bi-exciton, and the tri-exciton. Cross-correlations between the different emission lines are used for line identification. We have correlated the photon emission from the exciton and the bi-exciton, as well as the emission from the bi-exciton and the tri-exciton. The asymmetric results of these cross-correlations clearly demonstrate a three-photon cascade as the tri-exciton recombines to the ground-state via the bi-exciton and the exciton. A rate-equation model was used to fit the measurements in support of the experimental conclusions.