Taking OLEDs to Unexplored Frontiers

Conventional OLEDs are limited to thin transport layers and special electrode materials and/or pre-treatment due to the following restrictions: The conductivity of the charge carrier transport layers is low, leading to    ohmic losses. The injection of charge carriers from the electrodes into the transport layers    has a high barrier, leading again to an additional driving voltage increase. The organic stack of doped and undoped OLEDs is similar. In contrast to conventional OLED, Novaled PIN OLED® introduces an additional degree of freedom when it comes to product design. Hole and electron-transport as well as charge carrier injection are dramatically enhanced using Novaled PIN technology. As a result of doping, additional process steps, such as ITO treatment, are not needed. Additionally, a much wider range of materials used for the anode and cathode becomes available using p and n doping. In combination, this results in a very low driving voltage and high substrate compatibility of the Novaled PIN OLED®. Meanwhile the highest possible power efficiency and the longest possible life-time are maintained. Novaled has developed a number of doping and transport materials to be used in organic OLEDs to further enhance and support the already existing advantages. Furthermore Novaled uses a number of different interlayers and emitter materials, which can be easily integrated into Novaled's PIN structure. The principle architecture of a bottom emission OLED incorporating the intrinsic emission layers into the Novaled PIN OLED® technology by using doped transport layers: holes are injected from the anode and transported by p-hole transport layer (p-HTL) to the emitting layer (EML). Electrons are injected from the cathode and transported by the n-electron transport layer (n-ETL). Recombination of the charge carriers takes place in the EML and light is emitted.