Highly efficient vertical growth of wall-number-selected, N-doped carbon nanotube arrays

We demonstrate a straightforward approach for rapid growth of wall-number selected, N-doped CNT arrays. Highly uniform nanopatterned iron catalyst arrays were prepared by tilted deposition through block copolymer nanotemplates. PECVD growth of CNTs from the nanopatterned catalysts in an NH(3) environment generated vertical N-doped CNTs with a fine-tunability of their carbon wall numbers. The optimized growth conditions produced 52 microm long N-doped CNTs within 1 min. Owing to N-doping, the wall-number selected CNTs including DWNTs and TWNTs demonstrated enhanced electro-conductivity and chemical functionality. This remarkably fast growth of highly uniform N-doped CNTs, whose material properties and chemical functionalizability are reinforced by N-doping, offers a new area of large-scale nanofabrication, potentially useful for diverse nanodevices.