Photoconductive Properties of Smectic Liquid Crystalline Photoconductors

摘要

Recently it has been discovered that some types of liquid crystals exhibit very fast electronic conduction characterized by high mobility over 10~(-2) cm~2/Vs, which is 1000 to 10000 times higher than that of the amorphous organic semiconductors practically used. Now, the liquid crystals are being recognized as a new class of organic semiconductors, that is, Self-organizing molecular semiconductors. The liquid crystalline materials enjoy crystal-like self-organizing molecular alignment and liquid-like fluidity. These unique nature provide us with a good basis for their application to the photo-voltaics in terms of quality photo-electrical properties and feasibility of large-area application. The general aspects related to photoconductivity in liquid crystalline materials, especially charge carrier generation and carrier transport properties are reviewed on the basis of our experimental results on the smectic liquid crystals and discuss their high potential as a new type of photo-voltaic materials.