We show that the electrical conductivity of single walled carbon nanotubes (SWCNT) networks is
affected by oxygen and air humidity under ambient conditions by more than a magnitude. Later, we
intentionally modified the electrical conductivity by functionalization with iodine and investigated the
changes in the band structure by optical absorption spectroscopy.
Measuring in parallel the tubes electrical conductivity and optical absorption spectra, we found that
conduction mechanism in SWCNT is comparable to that of intrinsically conducting polymers. We
identified, in analogy to conducting polymers, in the infrared spectra a new absorption band which is
responsible for the increased conductivity, leading to a closing gap in semiconducting SWCNT.
We could show that by different functionalizations of the same SWCNT starting material the properties
like conductivity can be dramatically changed, leading to different imaginable applications. We investigated
here, an ultraviolet sensor with weakly modified SWCNT.
© 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license