Wall-selective probing of double-walled carbon nanotubes using covalent functionalization
Delphine Bouilly1, Janie Cabana, François Meunier
1Département de Physique, Université de Montréal, C.P. 6128 Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada.
ACS Nano
|May 21, 2011
Summary
Functionalizing double-walled carbon nanotubes (DWNTs) selectively modifies the outer wall, enabling inner wall electrical transport studies. This method distinguishes metallic/semiconducting properties and enables new DWNT electronic device designs.
Area of Science:
- Materials Science
- Nanotechnology
- Chemistry
Background:
- Double-walled carbon nanotubes (DWNTs) possess a unique coaxial structure offering inherent protection to the inner wall.
- Investigating DWNT properties and developing functional devices requires methods that can selectively probe individual walls.
Purpose of the Study:
- To introduce a reversible covalent functionalization method for DWNTs.
- To demonstrate selective modification of the outer wall while preserving the inner wall.
- To enable detailed characterization of DWNT electronic properties and explore new device applications.
Main Methods:
- Utilized aryldiazonium salt for covalent functionalization of DWNTs.
- Employed thermal annealing for reversible functionalization.
- Conducted electrical transport measurements on functionalized DWNT transistors.
Main Results:
- Functionalization occurred exclusively on the outer wall, leaving the inner wall chemically intact.
- Electrical current was confirmed to be carried by the inner wall.
- Successfully identified the metallic or semiconducting nature of both inner and outer walls.
- Gained new insights into current saturation phenomena in DWNTs at high bias.
Conclusions:
- Wall-selective functionalization of DWNTs is an effective strategy for probing their properties.
- This method allows for the unambiguous determination of wall-specific electronic characteristics.
- The approach facilitates the design of novel DWNT-based electronic devices with tailored functionalities.
