Low cost printed electrodes for OLED lighting

Organic Light Emitting Diode (OLED) is a new emerging technology that is energy efficient and environment friendly lighting replacement for current lighting technologies such as incandescent bulbs and fluorescent tubes. As performance of OLEDs has improved over the last several years it has demonstrated the potential to reach parity with LED lighting. However cost remains a major obstacle for main stream adoption and commercialization. According to DOE SSL road map, 40% of material cost is the cost of integrated substrates which include glass, ITO with metal grids and light-out-coupling (LOC) layers. As panel size increases, conductivity of ITO will not be sufficient to ensure brightness uniformity and power efficiency. Current best commercially available ITO substrates have sheet resistance & gt; ~5 ohms/sq. This is insufficient for large area panel with pixel size & gt; ~ 3x3 cm. Metal grids are needed in order to reduce sheet resistance of anode and hence reduce power consumption and improve luminance uniformity of OLED. In this proposal we demonstrate large area OLED panels on low cost anode structure by using inkjet printed grids using a novel high conductivity reactive silver ink and integrate the grids with Plextronics hole-injection layer (HIL). In order to reduce both material cost as well as increase thru-put by minimizing number of photolithography steps, inkjet printing will be used to fabricate anode structure. Printing offers direct patterning as well as high material utilization and thus potential for significant cost reduction. By process development and process integration of grids and HIL we demonstrate low cost printed anode structure that enables large area OLED panel manufacturing. Our proposal supports the development of affordable, large OLED lighting required for commercial applications such as custom lighting used in retail displays.