Emma Jane Brown

Recent developments in materials for TFT/PDLC devices

Liquid crystal mixtures for use over an active matrix substrate must have a high resistivity and, to maintain high value during the lifetime of the display, the materials must be very stable. Many such liquid crystal mixtures are known and used in twisted nematic displays but they are of low birefringence; very few high birefringence liquid crystals of this type are known. Several classes of liquid crystal which fulfill these criteria have been developed and formulated into low melting point mixtures suitable for use with UV curing prepolymers. The properties of PDLC films containing these new mixtures show that the high birefringence values now possible can lead to substantially increased contrast ratios.

Laterally fluorinated tolanes of low melting point

Abstract Tolanes having a terminal polar group and a lateral fluoro substituent are reported with the desirable features of high birefringence, wide nematic range and low melting point.