OLED-TV Display/Monitor Technology News

"Several aspects of ITO make it far from optimal for high-performance OLEDs" Dr. L. Jay Guo explains to Nanowerk. "It is known that the migration of indium and oxygen from ITO into organic semiconductors during OLED operation causes device degradation; the electrical properties of ITO greatly depend on the film preparation; the rough surface of the deposited ITO film and the work function of ITO limit the efficiency of the hole injection; moreover, the cost of ITO has escalated in recent years because of the jump in price of the element indium."
Guo, an associate professor of Electrical Engineering & Computer Science at the University of Michigan, has come up with semitransparent metal electrodes, fabricated by nanoimprint lithography (NIL), that, with further optimization, could replace today's use of conventional ITO electrodes in OLEDs. The core findings of this research is that a nanowire metal grid can provide sufficient optical transparency and electrical conductivity for it to be used as a transparent electrode for organic optoelectronic applications. These metal electrodes contain no expensive metallic elements and do not suffer from atomic diffusion but are nevertheless very efficient. Guo and his team demonstrated working OLED devices by using metal mesh electrodes made of different metals, including copper, which is very inexpensive.
"We believe this new electrode structure could also help solve another big problem in ITO-based OLED displays, which is the light trapping in the ITO layer due to its higher refractive index than the organic materials" says Guo. "This currently results in less than 25% of the generated photons to actually come out of the device and become useful."
read more at nanowerk