Charge transport in mesomorphic derivatives of perylene

Charge carrier mobilities have been measured in the solid and liquid crystalline phases of peripherally alkyl-chain substituted perylene derivatives using the pulse-radiolysis time-resolved microwave conductivity technique, PR-TRMC. By varying the alkyl substituents, the structure of the materials can be changed from a two-dimensional layered arrangement of the perylene units to one-dimensional, hexagonally packed columnar stacks. In all cases the pseudo-isotropic mobility within organised domains, σμTRMC, is found to lie within the range 0.01 to 0.1 cm2/V/s and is only slightly dependent on temperature. In contrast to other discotic materials previously studied, no pronounced sharp decrease in σμTRMC is found at the crystalline solid to liquid crystal phase transition.