ATOMIC-STRUCTURE AND LUMINESCENCE EXCITATION OF GAAS (ALAS)N(GAAS)M QUANTUM WIRES WITH THE SCANNING TUNNELING MICROSCOPE/

We report on the imaging of a molecular beam epitaxially grown GaAs/(A lAs)n(GaAs)m quantum well-wire array by means of cross-sectional scann ing tunneling microscopy (XSTM) and scanning tunneling-induced lumines cence (STL). XSTM provides atomically resolved cross-sectional images of sets of quantum well wires with chemical sensitivity within the gro up III species and electrical sensitivity to single dopant atoms. This permits the precise observation of growth mechanisms and the identifi cation of defects responsible for inhomogeneities in the growth morpho logy, as well as the determination of dopant incorporation throughout the structure. STL permits the relative quantum efficiency of individu al quantum wires to be quantified.