show how the radiative Auger process enables to determine the behaviour of a single-electron in the QD (energy quantization, relaxation and tunneling dynamics) using the precise, sensitive and fast tools of quantum optics. The radiative Auger process only requires significant Coulomb interactions within the trion, a very general feature. Therefore, this process should be observable for other quantum emitters in the solid-state.

Acknowledgments {#sec:acknowledgement}
===============

We would like to thank Philipp Treutlein for fruitful discussions. MCL, CS, and RJW acknowledge financial support from NCCR QSIT and from SNF Project No. 200020\_156637. LZ received funding from the European Union Horizon 2020 Research and Innovation programme under the Marie Skłodowska-Curie grant agreement No. 721394 (4PHOTON). JR, AL, and ADW gratefully acknowledge financial support from the grants DFH/UFA CDFA05-06, DFG TRR160, DFG project 383065199, and BMBF Q.Link.X 16KIS0867. LM and PL gratefully acknowledges financial support from the Danish National Research Foundation (Center of Excellence Hy-Q, grant number DNRF139) and the European Research Council (ERC Advanced Grant SCALE).

Author Contributions {#sec:contrib}
====================

MCL, CS, LZ, GNN, AJ performed the experiments. JR, ADW, and AL grew the samples. CS, MCL, LM fabricated the different samples. MCL, LZ, PL, AL designed the samples. MCL, CS, LZ, 