Highly Segmented OLEDs for Exterior Automotive Lighting and Safety Communication

We will develop exterior automotive lighting and safety communication product technology that reduces energy consumption compared to current LED products and adds safety communication functionality not possible with LED products. The technology developed will enable daytime visible safety communication using highly segmented OLED lighting panels that are significantly brighter than today’s OLED automotive lighting panels and significantly brighter and lower cost than OLED displays. The technology developed in this proposed project can also be applied to interior building lighting to add safety communication functionality to standard ceiling or wall mounted lighting fixtures. We will accomplish this advancement by combining a highly stacked OLED formulation with a unique cost-effective OLED substrate. Automotive manufacturers are currently using red OLED lighting panels for the exterior tail position function in the rear combination light (“RCL”) and OLED displays for some interior applications. Audi has reported in publications and presentations that OLED tail position lighting panels are more energy efficient than LED tail position lights of a similar uniformity as the OLED. This is because OLEDs are natural area light sources, while LEDs are point light sources that require optics to make them look uniform resulting in significant efficiency losses. The current red OLED automotive lighting panels consist of 1 stack or 2 stack OLED formulations on glass substrates consisting of 1 to 6 segments. The maximum brightness of these panels is about 1,000 to 2,000 cd/m2. With 1-6 segments the appearance of the tail position light can be modified easily by software, but with only a few large segments and only a maximum brightness of 2,000 cd/m2 these OLED panels cannot be used to communicate a variety of hazards, nor can they be easily seen in daylight conditions. More and smaller segments and higher brightness is needed. Alternatively, OLED displays can easily be used to create any number of hazardous symbols for safety communication, but with a typical maximum brightness of only 500 cd/m2 and the high cost of the active-matrix thin film transistor substrates, OLED displays are both too dim and too expensive to be used for exterior automotive lighting and safety communication. OLEDWorks has developed highly stacked OLEDs (6 stacks) for the white general lighting market and has demonstrated 2 stack red OLED panels with up to 60 segments for the exterior tail position function in the RCL for the automotive lighting market, but this project will develop technology that both increases brightness and increases segmentation to enable cost effective, daytime visible exterior automotive lights that can communicate a wide variety of safety related hazards symbols. The project will develop red OLED formulations of 3 to 6 stacks to increase brightness up to ~20,000 cd/m2 and will develop unique cost-effective substrates capable of up to ~1,000 segments per panel. In addition, a standard 6 stack white OLED formulation will be deposited on the highly segmented substrates to demonstrate the added feature of safety communication for interior building applications.