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

TL;DR

This study uses high-resolution spectroscopy to analyze the optical transitions and charge states of individual InAs/GaAs quantum dots, revealing detailed insights into their energy levels and carrier interactions.

Contribution

It provides the first comprehensive analysis of single-carrier energy levels and interactions across different charge states in quantum dots using excitation spectroscopy.

Findings

Detailed understanding of energy levels for neutral and charged states

Identification of selection rules for optical transitions

Insights into carrier interactions within quantum dots

Abstract

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.