Display applications

State-of-the-art polymer LEDs now have operating lifetimes and luminous efficiencies suitable for a wide variety of commercial applications. Furthermore, it is clear that the fundamental limits of polymer LED performance have not yet been reached. With improvements in material synthesis, fabrication techniques, and device design, significant increases in LED performance are to be expected. These improvements should lead to the extensive use of polymer LEDs in future display applications. 

Five-membered sulfur-containing heterocycles are important synthetic intermediates and have found a variety of applications in medical, agricultural, and material chemistry. Looking for potential candidates for ferroelectric display applications. Seed s group investigated the preparation of liquid crystals... 

Questions similar to these are being researched by chemical engineers who are active in the broad field of colloid and interface science. Future contributions by chemical engineers may be the key to the success of the EPID concept in visual display applications. 

In simple single-site liquid crystal models, such as hard-ellipsoids or the Gay-Berne potential, a number of elegant techniques have been devised to calculate key bulk properties which are useful for display applications. These include elastic constants for nematic systems [87, 88]. However, these techniques are dependent on large systems and long runs, and (at the present time) limitations in computer time prevent the extension of these methods to fully atomistic models. 

Blue luminescence of zinc complexes of pyridyl-containing complexes is an area of current interest.277 Design of blue luminescent materials is of relevance to display applications, as blue-light-emitting diodes, and to this end Che examined solution luminescence of zinc pyridylamine complexes.73,278 Che and co-workers studied the complex Zn40(7-azaindoyl)6 which has a blue emission at 433 nm in the solid state.279,280 In an attempt to improve on stability Wang et al. examined compounds with neutral 7-azaindole and an A-functionalized pyridyl derivative.281 In contrast with other metal complexes of the neutral 7-azaindole (32), Zn(7-azaindole)2(OAc)2 is a blue luminescent compound and a A-(2-pyridyl) 2-azaindole (33) and its complexes were also... 

Iridium as an electrode material has received considerable attention in the last decade not only because of its excellent catalytic properties but also in relation to the electrochromic effect observed for anodic iridium oxide films (AIROF). Electrochromism of iridium was thought to be of technical relevance for display applications and triggered several studies of the electrochemical and optical properties of AlROFs [67, 85-88],... 

Lewis, J. Grego, S. Chalamala, B. Vick, E. Temple, D. 2004. Electromechanics of a highly flexible transparent conductor for display applications. Society of Vacuum Coaters 47th Annual Techn. Conf. Dig. 47 129-132. 

Liquid Crystal Displays (LCD). Liquid crystal displays, once limited to small devices such as calculators, are now displacing color CRT (cathode ray tube) displays in commercial quantities. The ability to fabricate these display devices at high quality and at low cost is partially due to the wider spread use of photopolymer-based materials. Photopolymer technology is being used for the alignment of liquid crystal (LC) elements (49), the orientation of ferroelectric materials (50), the synthesis of LC polymers (57) and the manufacture of color filters for liquid crystal display applications (52). 

M Leadbeater, N Patel, B Tierney, S O Connor, I Grizzi, and C Towns, Blue LEP-OLED with 30,000 hours lifetime for flat panel display applications, SID Digest Tech. Pap., 35 162-163, 2004. 

A bewildering array of materials has been used as emitters in SMOLEDs since this early work on Alq3. In the following sections, we will present a brief review of host-guest emitter materials and give a perspective description of all the current state-of-the-art small molecule materials for emission at the three primary colors needed for full-color display applications. 

A Montali, C Bastiaansen, P Smith, and C Weder, Polarizing energy transfer in photoluminescent materials for display applications, Nature, 392 261-264, 1998. 

B.H. Lee, I.G. Kim, S.W. Cho, and S.H. Lee, Effect of process parameters on the characteristics of indium tin oxide thin film for flat panel display application, Thin Solid Films, 302 25-30, 1997. 

In addition to display applications, researchers are also exploring the use of vapor-deposited organic materials in devices such as photovoltaics [11], organic lasers [12], and organic thin-film transistors (TFTs) [13]. 

Y Tung, T Ngo, M Hack, J Brown, N Koide, Y Nagara, Y Kato, and H Ito, High Efficiency Phosphorescent White OLED for LCD Backlight and Display Applications, Proceedings of the Society for Information Display, Digest of Technical Papers, Vol. 35, Seattle, 2004, pp. 48-51. 

One of the main tasks for display applications is the combination of materials of different colors to produce white light and full-color devices. For that reason, separate strategies aim at the development of blue-, green-, and red-emitting materials with suitable color coordinates. 

For data transfer applications the modulation speed of an emitter is a decisive parameter. Here the long lifetime of the excited state in PS becomes problematic. The fall time of the EL is usually in the ps regime, while somewhat shorter values are reported for the rise time. Only for devices based on OPS has a significantly shorter fall time (0.03 ps) been reported [WalO]. For small signal modulations of the EL from PS, frequencies in the order of 1 MHz are reported Ts4, Co5]. Such modulation frequencies are sufficient for display applications. For data transfer via optical interconnects, however, they are much too low. 

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