Supercapacitive behavior of CVD carbon nanotubes grown on Ti coated Si wafer

Microwave plasma enhanced chemical vapor deposition (MPECVD) is used to grow carbon nanotubes (CNTs) on Ti coated n(+) Si wafers to fabricate supercapacitor electrodes. The thickness of the Ni catalyst and plasma pretreatment parameters determine the morphology and subsequent capacitor behavior of the as-grown CNT films. CNT electrodes fabricated by this simple, low cost approach have demonstrated stable and consistent capacitor behavior for a wide range of scan rates. A high capacitance similar to 4 mF/cm(2) is observed at the scan rate of 200 mV/s, using a less corrosive 0.1 M KCl aqueous solution as the electrolyte. Moreover, vertically aligned CNTs fabricated by this method give rise to better electrode platform configuration for further integration with transitional metal oxide, via simple sputtering technique, to enhance the supercapacitive performance. (C) 2008 Elsevier B.V. All rights reserved.