A comparative study on preparation of conductive and transparent carbon nanotube thin films

In this study we evaluated the optoelectronic performance of transparent conductive films of carbon nanotubes from the various commercial carbon nanotube materials and the different preparation methods. The sheet resistance and the optical transmittance can have a significant difference for the different carbon nanotubes. According to the thermogravimetric analysis and Raman spectra, we found that the optoelectronic performance of commercial carbon nanotubes mainly depends on the ratio of G-band intensity to D-band intensity, less on impurity, defects and length. It was also found that the optoelectronic properties of carbon nanotube thin films also depended on the preparation method. The sheet resistance of the thin films prepared by the various methods decreases in the sequence: airbrushing > filtration > clip coating. Observing in the TEM images and mechanical strength of the thin films, the fact that dip coating method shows the best performance might result from the closer contact of carbon nanotubes and the alignment structure. (C) 2011 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.