Ionic influences on the formation and evolution of domains in ferroelectric liquid crystal cells

In this paper the large extent to which ionic impurities within a ferroelectric liquid crystal cell can influence the outcome of a partial switching sequence is discussed. Both memorisation and enhanced switching effects are observed and are a direct result of the redistribution of ions within the cell. Memorisation of the areas switched in a pixel occurs when the ions are allowed time to drift and compensate the field set up by the molecular dipoles in switched or unswitched areas. Enhanced switching occurs when large reset pulses are applied before an opposite polarity partial switching pulse. Both of these effects persist even though the elastic state of the cell prior to the switching pulse always appears the same.

Keywords:

• Ferroelectric liquid crystal
• domain switching
• ions
• grey scale