Doping and Dedoping in SWCNT Film by the Spontaneous Redox Process

Single-walled carbon nanotube (SWCNT) film was deposited with MnO(2) using a spontaneous redox reaction between MnO(4)(-) ions and the SWCNTs. Doping and dedoping had a significant effect on the sheet resistance of the resulting SWCNT film. The injection of holes in the SWCNT film bleached the van Hove singularity transitions (E(11)(s)) observed by optical absorption spectroscopy. The observed doping was not permanent, and spontaneous reduction under ambient conditions restored the efects and dedoped the SWCNT film. Dedoping increased the Fermi level and restored the van Hove singularity transitions (E(11)(s)). The doping and dedoping mechanism of these films was investigated. Transmission electron microscopy, X-ray photoelectron spectroscopy, and optical transmission spectroscopy were used to characterize the films.