Liquid crystal displays, LC-materials and LPP photo-alignment

Abstract

The invention of the twisted nematic liquid crystal display (TN-LCD) by Schadt and Helfrich in 1970 started the development of field-effect LCDs. Today, LCDs are the dominant flat panel display technology. Milestones in the ongoing research and development are sub-millisecond responding nematic liquid crystal (LC) materials, integration of silicon-driving electronics into display substrates, complex optical thin-films enabling excellent image quality and, last but not least, high resolution, contact-free photo-alignment/pattering of monomeric liquid crystals in displays and surface-aligned liquid crystal polymer (LCP) optical films. Photo-alignment of liquid crystal molecules by the linear photo-polymerization (LPP) technology enables high resolution, fast responding multi-domain LCDs with broad fields of view and complex, ultra-thin liquid crystal polymer retarder films. LCD-applications range from reflective displays for digital watches with virtually zero power consumption to large-area flat television screens with photographic resolution as well as to optical security elements and integrated optics devices. The commercial impact of the global LCD technology is illustrated by its annual turnover above $140billion. The seminar gives a personal overview of the multidisciplinary efforts between applied physics, material sciences and engineering which have enabled nematic liquid crystals of becoming the dominant flat panel display technology since 1970.