Controlling the Crystalline Quality and the Purity of Single-walled Carbon Nanotubes Grown by Catalytic Chemical Vapor Deposition

Hugo Navas (1) , Matthieu Picher (1, 2) , Raul Arenal (3, 4) , Etienne Quesnel (5) , Eric Anglaret (1) , Vincent Jourdain (1)

1 L2C - Laboratoire Charles Coulomb
2 LPN - Laboratoire de photonique et de nanostructures
3 University of Zaragoza - Universidad de Zaragoza [Zaragoza]
4 LEM - ONERA - CNRS - Laboratoire d'étude des microstructures [Châtillon]
5 LITEN - Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux

It is frequently observed that as-grown single-walled carbon nanotubes (SWCNTs) contain defects. Controlling the defect density is a key issue for the control of nanotube properties. However, little is known about the influence of the growth conditions on the formation of nanotube defects. In addition, SWCNT samples frequently contain carbonaceous by-products which affect their ensemble properties. Raman spectroscopy is commonly used to characterize both features from the measurement of the defect-induced D band. However, the contribution of each carbonaceous species to the D band is usually not known making it difficult to separately extract the defect density and relative abundance of each. Here, we report on the correlated evolution of the D and G' bands of SWCNT samples with increasing growth temperature. In the general case, three to four Lorentzian components are required to fit them. Coupled with HRTEM characterization, the low frequency components of the D and G' can be attributed to the contribution of SWCNTs while high frequency components are associated with defective carbonaceous by-products. The nature of these defective by-products varies with the type of catalysts and with the growth conditions.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Hugo Navas, Matthieu Picher, Raul Arenal, Etienne Quesnel, Eric Anglaret, et al.. Controlling the Crystalline Quality and the Purity of Single-walled Carbon Nanotubes Grown by Catalytic Chemical Vapor Deposition. 2012. ⟨hal-00802071⟩