QUANTUM-WELL LUMINESCENCE AT ACCEPTORS IN P-I-N RESONANT-TUNNELING DIODES

The electroluminescence (EL) spectra of forward biased p-i-n double-barrier heterostructures are investigated. Two EL lines, separated by about 20 meV, due to recombination in the quantum well are observed. Their intensities peak at bias voltages corresponding to electron and hole resonant tunnelling. By investigating a series of structures with different spacer layer thicknesses between the barriers and p-type contact layers and with intentional p-type delta-doping in the central plane of the quantum well, we are able to confirm that the lower-energy line corresponds to electron recombination with neutral acceptors in the quantum well.