Electroluminescence from coupled InGaAs∕GaAs quantum dots embedded in lateral p-i-n junctions

The authors report an observation of coupling in single quantum dot molecules embedded in lateral p-i-n junctions using electroluminescence spectra. With a graded dot density wafer, electroluminescence spectra from uncoupled and coupled stacked quantum dots have been observed. For coupled pairs of quantum dots, an anticrossing of direct and indirect recombinations is observed with a forward biased electric field where the two dots are in resonance.