Delocalized electron states in quantum dot molecules

We demonstrate 2-dimensional coupling of the electron states in lateral quantum dot molecules by excitation density and temperature dependent micro-photolumitiescence (PL) spectroscopy. The 2-dimensional coupling manifests itself in a quasi-continuous density of states due to delocalized electron states. It accounts for broad PL bands observed in excitation density dependent micro-PL and provides low-energy carrier redistribution channels between localized states, as evident from the temperature dependent micro-PL measurements.