Growth of vertically aligned carbon nanotubes on glass substrate at 450 °C through the thermal chemical vapor deposition method

This work demonstrates the growth of vertically aligned carbon nanotubes (CNTs) on glass substrate at a low temperature of 450 °C. The Co/Ti films prepared by the sputtering method were adopted for growing CNTs in a rapid heating and cooling chemical vapor deposition (CVD) chamber. It was found that the presence of Ti layer played an important role for catalyzing the CNT growth, and CNTs can not grow on glass substrate without Ti layer. CNTs can be synthesized at 450 °C on glass substrates by using the bimetallic film with Ti fractions of 38 and 48%; on the other hand, no CNT can be obtained when Ti with a fraction of 77% was adopted. The results obtained in this work were compared with the predictions based on the Ti–Co binary phase diagram. Besides glass substrate, for comparison, this study also deposited the same bimetallic catalyst on Si substrate and performed the growing process at 500, 600, and 700 °C. According to the results obtained in this study, a two-step processing to prevent the catalyst from poisoning during CNT synthesis is proposed.