Suppression of field screening in nematic liquid crystals by carbon nanotubes

Transient currents induced by the polarity reversal of an applied dc electric field have been measured in planar-aligned nematic liquid-crystal cells. Experimental results indicate that a minute addition of carbon nanotubes as a dopant leads to a reduction of the ion concentration and thus suppresses the undesired field-screening effect. Observed simultaneously is a higher charge mobility in the doped cells in the presence of a strong field. Such increase of mobility, in comparison with that of undoped counterparts, is attributed to the parallel alignment of both the long axis of carbon nanotubes and the nematic director along the electric field. (c) 2006 American Institute of Physics.