Electrophoretic Deposition of Carbon Nanotubes on 3-Amino-Propyl-Triethoxysilane (APTES) Surface Functionalized Silicon Substrates

Fabrication of uniform thin coatings of multi-walled carbon nanotubes (MWCNTs) by electrophoretic deposition (EPD) on semiconductor (silicon) substrates with 3-aminopropyl-triethoxysilane (APTES) surface functionalization has been studied extensively in this report. The gradual deposition and eventual CNT film formation on the organosilane treated silicon substrates is greatly assisted by the Coulombic force of attraction existing between the positively charged -NH2 surface groups of APTES and the acid treated, -COOH- functionalized negatively charged nanotubes migrating towards the anode (silicon) surface. The superior CNT coatings produced by EPD in comparison to the dip/immersion coating and the influence of isopropyl (IPA) based EPD suspension in the fabricated film quality have also been revealed in this study. The effect of varying APTES concentration (5%-100%) on the Raman spectroscopy and thickness of the deposited CNT film has been discussed in details, as well. The organosilane assisted deposition approach has eliminated the need of metal deposition in the EPD technique and has established an economical, fast and entirely room temperature solution-based fabrication strategy of CNT thin films for a wide range of next generation electronic applications.