Abstract
We have measured the doping induced optical absorption in segmented polyacetylene, [CDHy]x, in which either 15% or approximately 27% sp3-bonded CDH units. These sp3 defects, which can be called “conjugation-interrupting” defects have an average spacing considerably less than the length of a soliton. In order to introduce the charged soliton excitation, all samples were doped with iodine by in-situ vapor doping technique with various dopant levels. For a sample with 27% sp3 hybridization, we have found a new broad band around 1.12 eV with relatively lower intensity for lower sp3. We assigned this band as an absorption due to the neutral solitons. The optical properties of deuterated polyacetylene with sp3 defects including the comparison with ordinary polyacetylene, (CH)x, will be discussed.