One-step fabrication and characterization of silica-sheathed ITO nanowires

Novel In_1.94Sn_0.06O₃ (ITO)/amorphous SiO_x coreshell structures were successfully synthesized by simple thermal evaporation. Studies indicated that the coreshell structures typically consisted of a core of crystalline, ITO nanowires surrounded by a shell of amorphous, SiO_x tubular structures. We proposed a gold-catalyzed, vaporliquidsolid process as the dominant mechanism for the growth of the core ITO nanowires, whereas SiO_x was grown in a tubular structure by a simultaneous and dynamic process. The possible reason for the preferential formation of the SiO_x shells on the outside of the coreshell structures, is discussed. In regard to the core/shell structures, three emission peaks of 2.73, 3.06, and 1.65 eV were observed in the room-temperature photoluminescence measurements, and were attributed to the SiO_x shell.