Preparation and DC conductivity of an amorphous organic semiconducting system

TLDR: A series of semiconducting samples with non-crystalline structure was prepared by the thermal degradation of phenol formaldehyde resin at different heat treatment temperatures as discussed by the authors, and DC measurements on these organic materials yield an interesting extension of the existing knowledge about the amorphous state.

Abstract: A series of semiconducting samples with noncrystalline structure was prepared by the thermal degradation of phenol formaldehyde resin at different heat treatment temperatures. DC measurements on these organic materials yield an interesting extension of the existing knowledge about the amorphous state. The most important result is the fact that pyrolyzed phenol formaldehyde resins show a temperature dependence on conductivity which is characteristic for the Mott hopping mechanism and identical with that of layers made by evaporating Ge, Si, GaAs or carbon. Hence it does not seem to be the chemical composition that is determining the mechanism of electrical conduction in amorphous solids but only the physical structure.