OLED matrix-displays

The field of organic light emitting diodes (OLEDs) has matured considerably within recent years and first products are commercially available. After a brief review of the improvement of individual OLEDs we will focus on research topics for the preparation of passive matrix (PMOLED), active matrix (AMOLED) and full color displays. To date, the properties of organic matrix displays basically meet consumer product requirements. Anyhow an industrial cheap fabrication technology for reliable displays is not established yet. To meet the industrial demands for device fabrication a new horizontal in-line vacuum system for a mass-production compatible device manufacturing was installed. For material saving large area coatings the system accommodates up to 7" x 13" substrates. Different PMOLED-Displays based on vacuum deposited organic compounds have been prepared by various fabrication techniques. We demonstrate a 2 inch organic display with 24 x 32 single pixels and 0.9 x 0.9 mm(2) pitch whereby cathode texture was achieved using photoresist barriers featuring a distinct undercut. Due to the inherent limitations of multiplexing and in order to satisfy the need for large area, high resolution displays the basic concepts for an active matrix addressing scheme are dealt with. In this regard transparent and electrically inverted top-side emitting diodes (IOLEDs) will be demonstrated. The latter are advantageous for the incorporation of powerful n-channel thin film transistors in the AMOLED driver backplanes. An all-organic smart pixel device comprising a single Pentacene based organic field effect transistor (OFET) and a conventional OLED was successfully prepared. Furthermore a new flash-sublimation technique for the spatially selective deposition of small organic molecules will be presented. We prepared OLEDs comprising flash-deposited Tris-(-8-hydroxyquinoline) aluminium (Alq(3)) and Alq(3) doped with DCM2 which demonstrate the suitability of this technique for preparation of full-color displays based on small organic molecules.