U.S. Department of Energy - Energy Efficiency and Renewable Energy
Building Technologies Office – R&D Projects
PPG Industries Develops a Low-Cost Integrated OLED Substrate
With the help of DOE funding, PPG Industries, Inc., has developed a low-cost OLED substrate, using inexpensive soda-lime "float" glass that the company manufactures at high volume for the architectural industry. Float glass is thin sheet glass and is much less expensive than the borosilicate or double-side-polished display glass that's currently being used as substrates by OLED device manufacturers.
PPG has demonstrated that through careful selection and the proper processing, float glass can be used as a substrate for OLED lighting, resulting in significant material cost reduction. Four different anodes were developed as low-cost alternatives to indium tin oxide, with comparable performance, and two deposition technologies were used: physical vapor deposition (magnetron sputtering) and chemical vapor deposition. The selection of materials and technologies was based on cost, scalability, and compatibility. PPG has also demonstrated scalable light-extraction technologies that increase the efficiency of the OLED lighting devices by more than 30 percent.
In a second DOE-funded project, PPG plans to scale up selected anode and light-extraction technologies, using soda-lime glass, to commercialize a low-cost, large-area, integrated substrate for use in the fabrication of rigid general-illumination OLEDs. Production costs will be further reduced by developing manufacturing processes that use real-time inspection and process-control systems to ascertain the quality and uniformity of the substrate, which is critical for device consistency and materials-waste minimization.
6"x6" white OLED devices on PPG's float-glass-based substrate. The device on the right has an internal extraction layer that improves the efficiency by 32 percent.