Growth condition mediated catalyst effects on the density and length of horizontally aligned single-walled carbon nanotube arrays

Horizontally aligned carbon nanotubes (CNTs) with tunable length and density on flat substrates promise great opportunities for next-generation nanoelectronics. We utilized chemical vapor deposition (CVD) method to grow ultralong CNT arrays on Si/SiO₂ substrate under various growth conditions. We found that growth parameters, such as catalyst solution concentration, pretreatment time, and growth temperature, could provide a mediated platform to control the morphology of the CNTs by means of modifying the catalyst properties. The catalytic behaviors of the nanoparticles affected by the growth parameters were elaborately discussed. With the emphasis of growth condition in the CVD growth methodology, controllable synthesis of CNTs will reach a new level and enlighten the achievement of high-performance CNT-based nanodevices.