Stefano Tominetti

Getters for flat-panel displays

Getters play a crucial role in solution of the main technical issues on the way to commercial exploitation of new flat-panel technologies: packaging, reliability and lifetime. The production steps of flat-panel displays (FPDs) often include a long baking and exhaust process to minimize the impurity content prior to the final sealing, which dramatically increases the manufacturing costs up to a level that might be incompatible with mass production requirements. These problems can be tackled and solved by the introduction of a specific getter device that can permanently remove the undesirable species by the formation of irreversible chemical bonds. In this paper we will focus on long-studied FPD technologies such as vacuum-fluorescent displays, field-emission displays, and plasma display panels, showing how proper getter solutions based on special metal alloys can increase their lifetime and reliability and, in particular cases, also improve the manufacturing process conditions.

P-235L: Late-News Poster: Analysis of the Relationship Between OLED Performance and Dryer Characterization

The successful exploitation of OLED/PLED displays is dependent on the control and removal of moisture from the device. Pixel shrinkage and luminosity reduction during the operating conditions are the most relevant issues, related to the moisture concentration into the device. Results show a strong link with dryer absorbing speed more than total capacity, as forecasted by a suitable model.

Alkali metal sources for OLED devices

In OLED organic layers electron injection is improved by using alkali metals as cathodes, to lower work function or, as dopants of organic layer at cathode interface. The creation of an alkali metal layer can be accomplished through conventional physical vapor deposition from a heated dispenser. However alkali metals are very reactive and must be handled in inert atmosphere all through the entire process. If a contamination takes place, it reduces the lithium deposition rate and also the lithium total yield in a not controlled way. An innovative alkali metal dispensing technology has been developed to overcome these problems and ensure OLED alkali metal cathode reliability. The alkali Metal dispenser, called Alkamax, will be able to release up to a few grams of alkali metals (in particular Li and Cs) throughout the adoption of a very stable form of the alkali metal. Lithium, for example, can be evaporated “on demand”: the evaporation could be stopped and re-activated without losing alkali metal yield because the metal not yet consumed remains in its stable form. A full characterization of dispensing material, dispenser configuration and dispensing process has been carried out in order to optimize the evaporation and deposition dynamics of alkali metals layers. The study has been performed applying also inside developed simulations tools.

53.2: Alkali & Alkaline-Earth Metal Sources for OLED Devices

Electron injection in OLED organic layers is improved by using alkaline-earth or alkali metals as cathode layers or as dopants inside organic layers. An innovative metal dispensing technology has been developed to overcome handling problems and to ensure controlled and reliable metal layers deposition for OLEDs.