Preparation of Carbon Nanowall by Hot-Wire Chemical Vapor Deposition and Effects of Substrate Heating Temperature and Filament Temperature

The preparation of carbon nanowalls (CNWs) by hot-wire chemical vapor deposition (HWCVD) and the effects of substrate heating temperature T h and filament temperature T f in this method have been investigated. The CNWs can be prepared by HWCVD using CH 4 without H 2 dilution. The wall size obtained from the scanning electron microscope image and the Raman peak intensity ratio of the G peak to the D peak of the sample changed with T h and T f . However, both were maxima at a substrate surface temperature T s of 730–740 °C, which was not the same as T h , and this result was independent of T f . The CNWs did not grow at T f of 1850 °C, because the T f of 1850 °C was insufficient for the decomposition of CH 4 . On the basis of these results, we show that T h , i.e., T s is a more important parameter than T f in the preparation of CNWs by HWCVD.