Electroluminescence of a quantum dot cascade structure

Abstract

We present electroluminescence and photocurrent measurements on InAs quantum dots that are embedded into a cascaded GaAs/AlAs structure. Compared to a quantum cascade laser, population inversion in a quantum dot cascade laser should potentially occur at a lower threshold. The electroluminescence spectra of our device peak in the midinfrared at about 150 meV. From the polarization behavior of the electroluminescence, we conclude that quantum dots are the origin of the optical transition.