Short Reduction Layer Process Development for OLED Lighting Panels

Project Summary/Abstract: With many OLED lighting panel makers reporting reliability issues, the most common being sudden failure of a panel to emit light due to a short circuit between the anode and cathode, this project will develop new methods and technologies to elevate reliability from 1 failure in 1000 panels to 1 in 10,000, and beyond. OLED lighting is projected to grow to be a $5B industry worldwide by 2025, and be a significant part of the US energy savings due to Solid State Lighting, which is projected to be 217 TWhr in 2025. Poor reliability slowed market adoption of CFLs it is important not to repeat this with OLED lighting. Technology was developed at Kodak (US Patent 7183707) to deposit a thin inorganic layer with the correct resistivity properties over the anode before the organics, a step known as Short Reduction Layer (SRL). Initially deposited by sputtering, a superior method is by Atomic Layer Deposition (ALD) to create almost defect-free uniform layers. The first version of this technology is used in all of OLEDWorks current OLED lighting products. There is great opportunity to increase the performance of the SRL through the combined use of our understanding of the growth dynamics of shorts in OLED lighting panels, and resulting understanding of the key physical properties required for improved SRL films. New materials suitable for making ALD films will be introduced and used in single layer and multi layer structures, which will be tested in sufficiently large numbers of OLED lighting panels to determine their efficacy for preventing shorts. Phase 1 will be used to find the most effective SLR films within the scope of the material set, the processing constraints, and the performance requirements. A successful higher performing SRL layer would reduce shorts due to all manner of roughness, hence enabling multiple cost reduction possibilities in OLED lighting, most associated with the use of lower cost substrates, lower cost anodes and patterning methods, and lower cost bus metal auxiliary electrodes. These cost reductions could significantly accelerate the market adoption of OLED lighting, with the attendant energy savings to energy consumers. Keywords: OLED lighting, reliability, shorting, Short Reduction Layer Summary for Members of Congress: OLED lighting will be a very important part of Solid State Lighting in the US for saving energy. Good reliability is critical for rapid market adoption. This project will develop improved technology to increase reliability by reducing early failures due to shorting in future OLED lighting products.