Carrier range on finite, isolated molecular wires in a monomer crystalline matrix: Example: polydiacetylene, 4BCMU Original Research Article

Photoconductive properties of isolated polydiacetylene 4BCMU chains in a diacetylene monomer matrix are studied using a charge collection technique after pulsed UV irradiation. These new results show that in partially polymerised diacetylene crystals, the carriers travel distances approximately proportional to the degree of polymerisation and substantially greater than the length of the individual, electronically isolated, chains. Mechanisms whereby this unusual property may come about are discussed including interchain tunnelling, Coulomb glass formation and non-random filamentary polymerisation resulting in an extended collection of chains growing preferentially end to end after some initially random chain initiation events.