Distortion of carbon nanotube array and its influence on carbon nanotube growth and termination

Well-aligned carbon nanotubes (CNTs) were produced by thermal chemical vapor deposition (CVD) of C2H4/H2/Ar on Fe/Al catalyst films. CNT growth kinetics and the array microstructure were investigated for the densely grown CNT films. A new CNT curling-controlled growth model is presented for the CNT growth kinetics. In this curling-controlled base-growth model, the initial CNT growth rate is relatively stable but the rate decreases dramatically after the initial period. It is found that, instead of the CNT film height, the curling of freshly grown CNTs is the essential cause of the CNT growth rate decrease and termination and this is in consistent with the Knudsen-diffusion theory.