Aligned van der Waals Coupled Growth of Carbon Nanotubes to Hexagonal Boron Nitride

1D carbon nanotubes (CNTs) are grown on hexagonal boron nitride (hBN) surfaces. The nanotubes show clear preference to align to specific crystal directions of the hBN substrate. Raman spectra confirm that the nanotubes consist of sp² carbon, while nanomanipulation shows that they are van der Waals coupled to the underlying hBN substrate. Scanning conductance and electric force microscopy show that the CNTs have significantly greater electrical conductance compared to the hBN. This integrated aligned growth of materials with similar lattices, yet having dissimilar dimensionality and electrical conducting properties, provides a promising route to achieving intricate nanoscale electrical circuits on high-quality insulating substrates.