Excitation spectroscopy of single quantum dots at tunable positive, neutral and negative charge states

Y. Benny, Y. Kodriano, E. Poem, T. A. Truong, P. M. Petroff, D. Gershoni

Published 2012-07-24Version 1

We present a comprehensive study of the optical transitions and selection rules of variably charged single self-assembled InAs/GaAs quantum dots. We apply high resolution polarization sensitive photoluminescence excitation spectroscopy to the same quantum dot for three different charge states: neutral and negatively or positively charged by one additional electron or hole. From the detailed analysis of the excitation spectra, a full understanding of the single-carrier energy levels and the interactions between carriers in these levels is extracted for the first time.