Acetylene flow rate effect on morphology and structure of carbon nanotube thick films by low pressure chemical vapor deposition

Carbon nanotube (CNT) films were prepared on nickel foil substrates by low pressure chemical vapor deposition (LPCVD) with acetylene and hydrogen as the precursors. The effect of acetylene flow rate on the morphology and structure of CNT films was investigated. The morphology and structure of CNTs depending on the acetylene flow rate were characterized by scanning electron microscope, transmission electron microscope and Raman spectroscope, respectively. With increasing the acetylene flow rate from 10 sccm to 90 sccm, the growth rate of CNT films increases and the thickness increases from 400 μm to 1000 μm, while the diameter of the CNTs increases from 10 nm to 300 nm. Also, the defects and amorphous phase in the CNT films increase with increasing the acetylene flow rate.