Electroluminescent liquid crystals

High-resolution circuitry and active devices employing Langmuir-Blodgett film techniques or polymer-based transistors are being considered for the sophisticated electronics required in future vehicles. Temperature or energy balance in the vehicle could be controlled through conductive polymers or semiconductor deposits on electrochromic windows. Electroluminescent liquid crystals and fluorescent and electrochromic materials used for visual displays show promise for future development. 

Keuker-Baumann, S., Bock, H., Sala, F.D., Benning, S.A., Hassheider, T., Frauenheim, T., Kitzerow, H.S. Absorption and luminescence spectra of electroluminescent liquid crystals with triphenylene, pyrene and perylene units. Liq. Cryst. 28, 1105-1113 (2001)... 

Contoret, A.E.A., et al. The photopolymerization and cross-linking of electroluminescent liquid crystals containing methacrylate and diene photopolymerizable end groups for multilayer organic light-emitting diodes. Chem. Mater. 14(4), 1477-1487 (2002)... 

Monomers of die type Aa B. are used in step-growth polymerization to produce a variety of polymer architectures, including stars, dendrimers, and hyperbranched polymers.26 28 The unique architecture imparts properties distinctly different from linear polymers of similar compositions. These materials are finding applications in areas such as resin modification, micelles and encapsulation, liquid crystals, pharmaceuticals, catalysis, electroluminescent devices, and analytical chemistry. 

M. Grell, D.D.C. Bradley, M. Inbasekaran, and E.P. Woo, A glass-forming conjugated main-chain liquid crystal polymer for polarized electroluminescence applications, Adv. Mater., 9 798-802, 1997. 

Cathode ray tubes (CRTs) are almost universally used in colour televisions and still dominate in the display monitors of desktop computers. They are obviously not suitable for laptop PCs, because of bulk and weight, where currently liquid crystal displays are the systems of choice. Neither are they the most suitable technology for very large area displays, where other display techniques such as plasma panels and electroluminescent devices offer advantages. 

The crosslinkable COCs have been suggested for the use as alternatives for a glass substrate of a liquid crystal display devices and an electroluminescence (EL) display devices. Moreover, a crosslinkable COC can be used as a polarizing film, surface protective film, retardation film, transparent conductive film, light diffusion film, film for EL display devices, transparent conductive composite material, anti-reflection film, etc. Methods how to prepare these types of films have been described in detail (47). 

Other glass-ceramics may find potential use in liquid crystal and electroluminescent displays. 

Electronic Displays Large area capability of l.B films is an advantage, the monolayers can either be the active electroluminescent layer or used to enhance cihcicncy of an inorganic diode passive application to align liquid crystal displays. Deposition of liquid-crystal type molecules also possible. 

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