Magneto-optical studies of ballistic electron transport in single barrier heterostructures

We report an investigation of ballistic electron transport in GaAs/AlGaAs p-i-n single barrier structures with magnetic fields of up to 14T applied parallel to the tunneling direction (B//z). The energy distribution and relaxation processes of the non-equilibrium electron population injected into the p-doped collector from the Landau levels of the emitter accumulation layer are studied by means of electroluminescence (EL) spectroscopy. The observation of emitter Landau level structure in the ballistic electron EL spectra shows that the 2D to 3D tunneling process is elastic. In addition to the ballistic electron EL, cross-barrier recombination between the electron and hole accumulation layers is observed. This allows a precise determination of the initial energy distribution of the injected electrons.