Structure and Photoluminescence of Metal Oxide Core-Shell Nanowire Arrays

Abstract

Metal oxide core-shell nanowire arrays composed of electrodeposited ZnO nanowires and atomic layer deposited Al2O3, ZnO, and TiO2 shells were fabricated at low process temperatures. The structural and photoluminescence (PL) properties of the core-shell structures were investigated and distinctive features were induced by the shell coatings. Due in part to their low temperature deposition, the effects of annealing on the core-shell nanowires were also studied in detail. The room temperature and low temperature PL of the nanowire cores are affected by the annealing treatments and the shell layers, with diverse effects observed depending on the shell material. Evidence for solid state reactions between the ZnO core and metal-oxide shell at increased annealing temperatures was also observed, leading to further changes in their optical properties.