The impact of materials on liquid crystal display technologies

Today, and for the foreseeable future, the leading flat panel display products are those based on supertwisted nematic (STN) and active matrix LCDs. Worldwide sales of these products are presently $3.5 billion and $6 billion respectively and are predicted to reach $4.2 billion and $9 billion by the end of the decade. Since coming to prominence in the mid-1980s, both technologies have obviously experienced explosive growth. This remarkable achievement has been underpinned by the introduction of new materials and techniques. Of particular importance are amorphous silicon, which is used as the semiconductor in the thin film transistors used in active matrix LCDs, and anisotropically conducting adhesives which have indirectly enabled improvements in the visual performance of supertwist LCDs. The future challenge for LCD and material scientists is the development of reflective colour displays. The most promising approach appears to be based on active matrix-addressed dye phase change LCDs with internal colour reflectors. This approach will require the development of stable, ionically pure dyes and highly efficient thin film reflectors of red, green and blue Light.