Abstract: The photo-hole generation process in the smectic phases of a liquid crystalline photoconductor, 2-(4'-octylpheny)-6- dodecyoxylnaphthalene (8-PNP-012) was investigated by using steady-state and transient photocurrent measurements. It was revealed that the photo-generation of holes was governed by two different processes: Onsager type of photo-carrier generation in the bulk and electrode-enhanced hole injection induced by the charge transfer from photo-excited 8-PNP-012 molecules to the electrode interface. In the former process, for fairly high light intensity, the collected photo- generation charge was found to be approximately proportional to the square of the light intensity irrespective of the phase, suggesting the contribution of exciton-exciton interactions. And in the latter process, the photogeneration quantum yield can be one order of magnitude larger than that in the bulk generation process. We will discuss totally the photo-carrier generation process in mesophases of 8-PNP-012, in terms of exciton-exciton and exciton-electrode interactions including the effect of electrode materials and the disorder of molecular arrangement. !23
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