Lattice-directed growth of single-walled carbon nanotubes with controlled geometries on surface

How to control the orientations of single-walled carbon nanotubes (SWCNTs) on surface is the key point to controlling their geometries. In this work, we chose quartz (0 0 1), MgO (0 0 1) and layered mica with 3-, 4- and 6-fold symmetry, respectively as substrates to grow SWCNTs using gas-flow and lattice-directed modes. The produced SWCNTs were aligned along the symmetrical directions and displayed the homologous angles of 120°, 90° and 60° during growth on quartz (0 0 1), MgO (0 0 1) and mica surfaces, respectively. The obtained SWCNTs with controlled geometries would have wide applications in nanoelectronic devices in the future.