Papers by Author: Sandro Santucci

Abstract: Multi-walled carbon nanotubes (MWCNTs) have been grown, simultaneously at different temperatures (600 °C, 700 °C, 725 °C, and 750 °C), by thermal chemical vapour deposition (CVD) of acetylene (C2H2) gas, in ammonia (NH3) atmosphere. The samples have been characterized morphologically by scanning electron microscopy (SEM) and a structurally by Raman spectroscopy. These analyses show that, when the temperature of substrate increases, the CNT average diameter and the density distribution decrease, and the CNTs are less defective. However there is a temperature limit (725 °C) for CNT growth. We have grown CNTs onto Si3N4/Si substrates with Pt electrodes, in order to realize the gas sensing devices. The CNTs grown at 725 °C, exhibit a fast response and a high sensitivity to NO2 gas.

Abstract: The microstructural characterization of r.f. magnetron sputtered ZnO thin films deposited on 6H-SiC is presented with a comprehensive investigation of their properties as a function of annealing temperature and film thickness. These structures, with some modifications, are utilised as Schottky diode hydrogen gas sensors and Surface Acoustic Wave (SAW) devices.