Self-aligned growth of single-walled carbon nanotubes using optical near-field effects

Abstract

Self-aligned growth of ultra-short single-walled carbon nanotubes (SWNTs) was realized by utilizing optical near-field effects in a laser-assisted chemical vapor deposition (LCVD) process. By introducing the optical near-field effects, bridge structures containing single suspended SWNT channels were successfully fabricated through the LCVD process at a relatively low substrate temperature. Raman spectroscopy and I-V analyses have been carried out to characterize the SWNT-bridge structures. Numerical simulations using a high-frequency structure simulator revealed that significant enhancement of local heating occurs at metallic electrode tips under laser irradiation; it is about one order of magnitude higher than that in the rest of the electrodes. This technique suggests a novel approach to in situ low-temperature fabrication of SWNT-based devices in a precisely controlled manner, based on the nanoscale heating enhancement induced by the optical near-field effects.

Laser-assisted nanofabrication of carbon nanostructures

“…To address the challenges, a series of laser-assisted techniques were developed in LANE, including optically controlled parallel integration of CNTs into predesigned micro/ nano-architectures in a single step, 55,56 selective removal of metallic CNTs (m-CNTs) through laser irradiation, 54 and growing diameter-modulated single-walled CNTs. 53 …”

“…5(a). 55,56 The CNT-integrated structures were fabricated on SiO 2 /Si substrates prepatterned with electrodes. The electrodes consisted of multiple layers, including a ruthenium (Ru) layer (200 nm), aluminum (Al) layer (5 nm), iron (Fe) layer (1 nm), and Al layer (20 nm) sequentially from the bottom to the top.…”

“…Telephone achieved, including (1) laser-assisted direct writing twodimensional graphene, 51,52 (2) controlled growth and integration of carbon nanotubes, [53][54][55][56] and (3) fast growth of zerodimensional carbon nanoonions. 57 …”

Strong photoluminescence from diameter-modulated single-walled carbon nanotubes

“…[27][28][29][30] Temperature dependence of the SWNT diameter has also been studied by a few groups. [31][32][33][34][35] However, no report has been done investigating the PL emission of diameter-modulated tubes due to difficulties in fabrication and scalability of the structures.…”

“…[35][36][37] Silicon substrates coated with 2-lm-thick oxide layers were used as the substrates. Catalyst was deposited on the substrates by sputtering 1 nm Fe film for the growth of free-standing SWNTs.…”