Field induced alignment of carbon nanotubes directly grown on metal tips

It has been considered that a method that enables growth of carbon nanotubes (CNTs) directly onto a metal tip apex by chemical vapor deposition (CVD) is a promising method to fabricate CNT field emitter. However, this method requires appropriate method to control the alignment of CNTs. In this study, we have examined effect of electric field that was intentionally applied during the CVD on the alignment of CNTs on a tungsten (W) tips to fabricate the CNT field emitter with good CNT alignment. Our results imply that not only application of field induced stress of the order of 0.05 MPa but also control of growth mode of CNTs is required for the better alignment of CNTs on the W-tip.

► CNTs were grown directly on tungsten tips by a CVD method.
► Effect of electric field on alignment of the CNTs was examined.
► The result shows that field induced stress of the order of 0.05 MPa is required for the alignment of CNTs.
► Our results imply that the control of growth mode of CNTs is also required for the further alignment control of CNTs.