Far-infrared (λ=88 μm) electroluminescence in a quantum cascade structure

Abstract

Intersubband electroluminescence has been investigated in a quantum cascade structure based on vertical transition designed for far-infrared (λ=88 μm) emission. A narrow luminescence peak with a full width at half maximum of 0.7 meV is measured at low excitation currents (30 A/cm2) and low temperature (T=5 K). The electroluminescence efficiency exhibits a strong temperature and current dependence, consistent with an interplay between electron–electron and optical phonon scattering.