Nonresonant electrical injection of excitons in an InGaAs quantum well

The authors report on electroluminescence measurements combined with photoluminescence excitation spectroscopy on a single InGaAs quantum well placed in the intrinsic region of a p-i-n photodiode. They show that at low current density, the spectra are dominated by the spectrally narrow excitonic emission. Moreover when increasing carrier injection, they observe the progressive transition from excitons into free electron-hole pairs. This structure meets all criteria to be integrated in a semiconductor microcavity and the present demonstration of exciton electroluminescence is the first step toward the achievement of the strong coupling regime under electrical injection.