Midinfrared intraband electroluminescence from AlInAs quantum dots

Abstract

Midinfrared electroluminescence from a cascade of coupled AlInAs quantum dots and GaAs quantum wells at low temperature (80 K) is demonstrated. At low injection currents, the spectra show a clear peak at 158 meV with a luminescence width of 15 meV which is associated with transitions from the s shells of a resonant subensemble of quantum dots. A Stark shift to 143 meV and spectral broadening is observed at higher injection currents which is associated with luminescence from the inhomogeneously broadened quantum-dot ensemble. The reported design is a possible solution to obtain population inversion in unipolar quantum-dot-cascade structures.