New Low Work Function, Transparent Electrodes for Robust Inverted-Design OLEDs

Organic Light Emitting Diodes ,OLEDs, currently suffer from materials stability and shortened device lifetimes when driven to the levels required for general illumination. Although much progress has been made to extend the life of these devices, their lifetimes are still not adequate when driven to the 850 candel per meter squared required for illumination. Many of the problems stem from the choice of tin-doped indium oxide as the transparent conducting anode for most OLEDs. The use of ITO drives the need for a low work function reactive-metal cathode, which, together with the ITO itself, leads to many degradative processes. Previous work discovered a low work function, transparent version of a conducting polymer that can be processed from solvent dispersion. In this project, this new conducting polymer will be used as an efficient electron-injecting layer in conjunction with a low work function, transparent conducting oxide. The new configuration can be used to produce an inverted OLED device structure that eliminates the need for ITO, along with the need for the reactive metal cathode that causes so many problems. Commercial Applications and other Benefits as described by the awardee: Once OLEDs are fully developed, they will require only 50 per cent of the energy consumed by current conventional light sources to produce the same amount of light. A complete changeover from incandescent and fluorescent lamps to LEDs and OLEDs would save 25 billion dollars per year of electrical energy. These savings would reduce the demand for energy, which would prevent emissions of 45 million tons of carbon gasses annually and encourage the construction of 133 new power stations ,1000 MW each,