Formation of carbon nanowalls by pulsed filtered cathodic vacuum arc deposition

Abstract

In the present study, Carbon Nanowalls (CNWs) were produced by Pulsed Filtered Cathodic Vacuum Arc Deposition (PFCVAD) on glass substrates. A high purity graphite rod was used as a cathode target. Growth was performed by varying the distance between the target and substrate, namely 1 cm (1A250), 2 cm (2A250) and 3 cm (3A250). No CNW formation has been observed on the substrate, when the target and substrate distance is 3 cm. Amorphous nature of carbon structures has been shown with the Raman measurements. Raman mapping has been also performed to show the vertical wall structures of the CNWs. Surface morphology of the CNWs was investigated by Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) measurements. It has been found that the wall widths are roughly 1.8 mu m and 1.0 mu m for the samples 1A250 and 2A250, respectively. It has also shown that curvier vertical wall structures have formed for samples 2A250 compared to that of 1A250. X-ray Photoelectron Spectroscopy measurements have shown that 40% sp3 C-C bonding and C-O bonding which indicates the amorphous nature of the structure. Optical studies have shown that CNWs have low reflectance in visible region when the substrate to target distance is 1 cm which makes this thin coating very suitable for dark coating applications.