Carbon nanotubes growth by HFCVD: effect of the process parameters and catalyst preparation

Carbon nanotubes (CNTs) were grown on nickel catalysts by hot filament chemical vapour deposition (HFCVD) using H2 and CH4 as gas precursors. CNTs with different characteristics were observed varying some growth parameters, such as the substrate temperature, the total pressure and the methane concentration. These parameters were optimised in order to obtain untangled CNTs with high density and smooth walls. Catalyst nanoparticles were obtained through the clustering of Ni thin films deposited by sputtering techniques. CNTs grown on samples with the silicon native oxide or with a SiO2 coating between Si substrate and Ni film were compared. Catalytic layers and CNTs were characterised by SEM and XPS. [Copyright &y& Elsevier]