The organic light-emitting diode (OLED) is one of the most intriguing and most promising new technologies for electronic displays and lighting out there. OLEDs are like traditional light-emitting diodes, but they incorporate organic electroluminescent compounds that emit light when introduced to an electric current. Originally developed in the 1950s in France, OLEDs are used today in advanced high-contrast displays. Their low energy consumption makes them particularly attractive with today’s proliferation of electronic devices.
Although OLEDs are superior to more-conventional technologies such as liquid-crystal displays (LCDs) in terms of contrast ratio and material efficiency, they are typically manufactured by an expensive process involving glass doped with heavy metals. They are fragile and rigid as a result. To solve this problem, researchers from the Department of Materials Science and Engineering at the University of Toronto have developed a new plastic-based manufacturing method for OLEDs. The result is a more cost-effective, efficient, and flexible material.
“For years, the biggest excitement behind OLED technologies has been the potential to effectively produce them on flexible plastic,” says University of Toronto professor Zheng-Hong Lu. “This discovery unlocks the full potential of OLEDs, leading the way to energy-efficient, flexible, and impact-resistant displays.”
The applicability of OLEDs to large-area panels also makes them well-suited for lighting; several manufacturers have developed OLED light fixtures that emit evenly distributed planes of light without hot spots. And a multilayered configuration of OLEDs can deliver surprising results in multifunctional technologies. One such application is a switchable OLED panel that doubles as a transparent window. Recently developed by BASF and Philips for use in automobile roofs, the new skylight module allows clear views until illuminated—at which point it emits a homogeneous plane of light. The OLED panel is also a highly energy-efficient light source, as well as one that is less than 2 millimeters thick.
According to Felix Görth, head of Organic Light-Emitting Diodes and Organic Photovoltaics at BASF Future Business, “This combination allows the driver to enjoy a unique open-space feeling during the day and pleasantly suffuses the interior with the warm light of the transparent, highly efficient OLEDs at night.” Philips sees potential for OLEDs beyond the automobile application. “This project provides impressive evidence of new possibilities with OLEDs, and illustrates the potential of Philips’s Lumiblade OLED technology to help create innovative lighting applications that enhance people’s lives,” says Dietrich Bertram, Philips’s general manager of OLED Lighting.
If this venture is successful, architectural applications are bound to follow. Low-energy illuminating skylights, windows, and doors could be highly practical in some applications, especially given OLEDs’ potential long life. Moreover, OLED technology will facilitate a merger of the currently distinct worlds of lighting and electronic displays—enabling future physical environments that are illuminated by information.