Electron and hole storage in self-assembled InAs quantum dots

Abstract

We present results on optically induced storage of electrons or holes in self-assembled InAs quantum dots (QDs). The measurements demonstrate that, following resonant photo-excitation of the QDs, excitons can be ionised selectively leaving either electrons or holes stored. The stored charge is sensed via resistivity changes in a remote 2D carrier system. The induced photo-effect is persistent over time scales of >8h at a temperature of 145K. A series of resonances are observed in the spectral characteristics of the photo-effect. The charging probability was derived from the analysis of the temporal behavior of this charge storage effect.