Dopant-Enhanced Vertical Alignment Of Negative Liquid Crystals

A simple method for achieving high-contrast vertical alignment of high birefringence (Δn 0.28) negative dielectric anisotropic liquid crystal mixture using buffed polyimide substrates is demonstrated. By doping a positive, or non-polar dielectric anisotropic compound or mixture to the laterally difluorinated tolane liquid crystal host, an excellent vertical alignment was obtained. This alignment is stable throughout the entire nematic range. Its application for large screen liquid crystal televisions is considered