Comparison of the Stability of Surface-Modified SWNTs and DWNTs Network Films

Abstract

We studied the stability of single-walled carbon nanotubes (SWNTs) and double-walled carbon nanotubes (DWNTs) films as a function of surface modification. Conductivity measurements disclosed that gold ion and HNO3 treatment of the nanotube network films increased the electrical conductivity by more than a factor of 2 with negligible loss of transmittance. However, the long-term stability of the films varied depending on nanotube type and post-treatment method, with gold ion-treated nanotubes exhibiting higher stability than HNO3-treated nanotubes. Moreover, DWNTs showed better stability than SWNTs when treated with gold ions. Work function and optical absorption spectral measurements suggested that the dedoping process and the contact resistance of the nanotube networks may be important for stability under ambient conditions. These results are important for the development of surface-modified SWNTs and DWNTs for potential applications in solar cells, light-emitting diodes, sensors, and field-effect transistors.