Properties of electrophoretically deposited single wall carbon nanotube films

Abstract

This paper describes techniques for rapidly producing a carbon nanotube thin film by electrophoretic deposition at room temperature and determines the film mass density and electrical/mechanical properties of such films. The mechanism of electrophoretic deposition of thin layers is explained with experimental data. Also, film thickness is measured as a function of time, electrical field and suspension concentration. We use Rutherford backscattering spectroscopy to determine the film mass density. Films created in this manner have a resistivity of 2.14×10−3Ω·cm, a mass density that varies with thickness from 0.12 to 0.54g/cm3, and a Young's modulus between 4.72 and 5.67GPa. The latter was found to be independent of thickness from 77 to 134nm. We also report on fabricating free-standing films by removing the metal seed layer under the CNT film, and selectively etching a sacrificial layer. This method could be extended to flexible photovoltaic devices or high frequency RF MEMS devices.