Abstract
Photogeneration and carrier transport in a liquid crystalline photoconductor, 2-(4'-octylphenyl)-6-dodecyloxy-naphthalene (8-PNP-O12) doped with a small amount of C70 was investigated. C70 sensitized its photoconductivity not only in spectrum ranged from 400 nm to 700 nm but also in efficiency. It was found that the photogeneration for holes and electrons took place in the same efficiency when C70 was photoexcited, and that the photogeneration efficiency was increased with the increasing of electric field and doping concentration, which depended on its mesophases. The highest efficiency of 10-2 was obtained at the C70 concentration of 0.5mol% in the SmB phase. Interestingly, no doping effect on the carrier transport for electrons and holes was observed in that phase. These results indicate a possible application of liquid crystalline photoconductors to high-speed photosensors.
