New approach to n-doping of polyacetylene: Ion implantation

High density polyacetylene film HD-(CH)x was ion-implanted in order to control the conductivity and semiconductor characteristics (i.e., p-type and n-type) as a new technique of doping. When the original (CH)x is p-type, the Na⁺ implanted film shows diode characteristics in the current-voltage curve, which suggests the formation of p-n junction. We found that the diode characteristics is quite stable in the open air for more than a week. The depth profile of implanted Na⁺ in the film and the electronic conduction mechanism were discussed.