Illumination-induced nonequilibrium charge states in self-assembled quantum dots

Valentin, S.R. and Schwinger, J. and Eickelmann, P. and Labud, P.A. and Wieck, A.D. and Sothmann, B. and Ludwig, Ar.

Volume: 97 Pages:
DOI: 10.1103/PhysRevB.97.045416
Published: 2018

We report on capacitance-voltage spectroscopy of self-assembled InAs quantum dots under constant illumination. Besides the electronic and excitonic charging peaks in the spectrum reported earlier, we find additional resonances associated with nonequilibrium state tunneling unseen in C(V) measurements before. We derive a master-equation-based model to assign the corresponding quantum state tunneling to the observed peaks. C(V) spectroscopy in a magnetic field is used to verify the model-assigned nonequilibrium peaks. The model is able to quantitatively address various experimental findings in C(V) spectroscopy of quantum dots such as the frequency- and illumination-dependent peak height, a thermal shift of the tunneling resonances and the occurrence of the additional nonequilibrium peaks. © 2018 American Physical Society.

« back