Fabrication and implementation of large-area organic light-emitting-diode devices on direct patterned backplanes

In this paper, we report on a new cost-effective fabrication technology for large-area organic light-emitting diode (OLED) devices that we have developed. We fabricated OLED lighting devices on a directly patterned backplane using a dry process without employing conventional photolithography patterning technology. The indium–tin-oxide (ITO) anode, metal cathode, insulator, and emissive organic layer patterns were all formed directly on the substrates during the sputtering and evaporation steps by using a shadow mask without using etching or lift-off methods. We fabricated and characterized green phosphorescent emission OLED devices with an emission area of 30 × 120 mm2, based on backplanes formed by direct patterning technology. Application of direct patterning technology reduced the total number of processing steps to 4 from the 26 steps required by conventional photo-patterning technology, making it possible to reduce large-scale production cost. Although the process steps were reduced considerably, the typical characteristics were comparable to those of photo-patterned OLEDs. Furthermore, the lifetime of the OLEDs based on direct patterned backplane was observed to be 27,200 h, which is approximately 97% of the lifetime of conventionally patterned OLEDs.