Home About us Contact
|
Home About us Contact | ||
|
|
||
Flexible Displays (flexible + display)
Selected AbstractsCharacteristics of Solution-Processed Small-Molecule Organic Films and Light-Emitting Diodes Compared with their Vacuum-Deposited CounterpartsADVANCED FUNCTIONAL MATERIALS, Issue 10 2009Tae-Woo Lee Abstract Although significant progress has been made in the development of vacuum-deposited small-molecule organic light-emitting diodes (OLEDs), one of the most desired research goals is still to produce flexible displays by low-cost solution processing. The development of solution-processed OLEDs based on small molecules could potentially be a good approach but no intensive studies on this topic have been conducted so far. To fabricate high-performance devices based on solution-processed small molecules, the underlying nature of the produced films and devices must be elucidated. Here, the distinctive characteristics of solution-processed small-molecule films and devices compared to their vacuum-deposited counterparts are reported. Solution-processed blue OLEDs show a very high luminous efficiency (of about 8.9,cd A,1) despite their simplified structure. A better hole-blocking and electron-transporting layer is essential for achieving high-efficiency solution-processed devices because the solution-processed emitting layer gives the devices a better hole-transporting capability and more electron traps than the vacuum-deposited layer. It is found that the lower density of the solution-processed films (compared to the vacuum-deposited films) can be a major cause for the short lifetimes observed for the corresponding devices. [source] Surface-Modified High- k Oxide Gate Dielectrics for Low-Voltage High-Performance Pentacene Thin-Film Transistors,ADVANCED FUNCTIONAL MATERIALS, Issue 6 2007S. Kim Abstract In this study, pentacene thin-film transistors (TFTs) operating at low voltages with high mobilities and low leakage currents are successfully fabricated by the surface modification of the CeO2,SiO2 gate dielectrics. The surface of the gate dielectric plays a crucial role in determining the performance and electrical reliability of the pentacene TFTs. Nearly hysteresis-free transistors are obtained by passivating the devices with appropriate polymeric dielectrics. After coating with poly(4-vinylphenol) (PVP), the reduced roughness of the surface induces the formation of uniform and large pentacene grains; moreover, ,OH groups on CeO2,SiO2 are terminated by C6H5, resulting in the formation of a more hydrophobic surface. Enhanced pentacene quality and reduced hysteresis is observed in current,voltage (I,V) measurements of the PVP-coated pentacene TFTs. Since grain boundaries and ,OH groups are believed to act as electron traps, an OH-free and smooth gate dielectric leads to a low trap density at the interface between the pentacene and the gate dielectric. The realization of electrically stable devices that can be operated at low voltages makes the OTFTs excellent candidates for future flexible displays and electronics applications. [source] Plastic Electronics: The Influence of Morphology on High-Performance Polymer Field-Effect Transistors (Adv. Mater.ADVANCED MATERIALS, Issue 2 20092/2009) On p. 209, Wojciech Pisula, Klaus Müllen, and co-workers report on directionally oriented, high-performance polymer field-effect transistors for plastic electronics. The cover shows the applied alignment from solution, resulting in pronounced macroscopic ordering of the copolymer chains and finally in excellent transistor behavior, which is promising for applications in, for example, flexible displays. [source] Application and New Developments in Polymer-Dispersed Liquid Crystal Simulation StudiesMACROMOLECULAR THEORY AND SIMULATIONS, Issue 7 2007Young Jae Jeon Abstract Polymer-dispersed liquid crystals (PDLCs) represent an important new class of materials with electro-optic applications such as flexible displays, large-area devices projection displays, electrically switchable windows, etc. On considering such applications of these materials, many studies have been performed on the experimental side. Similarly, research on the simulation side for the PDLCs is of the fundamental interest too. The present article contains a short review on the present and past simulation studies of PDLCs. Various molecular simulation approaches applied to PDLC systems by different groups are reviewed here. In addition some new findings of the bulk phases are also extensively described. [source] | ||||||||||