With characteristics such as bendabilty, segmentation, transparency, and their nearly unlimited range of shapes, organic light-emitting diodes (OLEDs) facilitate diverse new design opportunities by virtue of their being efficient areal lighting sources fabricated on flexible substrates.
In 2015, scientists of the Fraunhofer FEP were successful for the first time in processing adjustable-color OLEDs on rigid substrates. This facilitated the extension of the application spectrum of OLEDs, such as for integration into vehicle interiors where the lighting levels should be controllable as a function of the time of day. Imagine employment as ambient or accent illumination, such as for lighting in museums and exhibitions, where the adjustability of color from just a single lighting component can present the works exhibited in different colors of light.
Just two years later, the next big development goal has now been reached: the Fraunhofer FEP now offers OLED emission systems featuring an adjustable color range integrated on flexible substrates. These types of OLED modules are able to switch the emitted color between two different color temperatures. In this way, a yellow-blue bi-color emission system can not only be switched between the pure emission colors of yellow and blue, but white light can also be generated through simultaneous activation of both colors.
The integration of adjustable-color OLEDs on flexible substrates brings their employment on curved surfaces in vehicle interiors such as roofs and curved fixtures into the realm of the tangible. In the meanwhile, the range of choice for substrates has also been broadened. Flexible OLEDs can be fabricated on metal and plastic films just as they can be on ultra-thin glass. The scientists will debut the new flexible variable-color OLED modules at the International Symposium on Automotive Lighting (ISAL). The symposium takes place directly after the International Motor Show Germany (IAA Pkw 2017) and addresses lighting applications in automobiles. The wide range of possibilities for OLED technology on flexible substrates for applications upon and in automobiles will be on display at the Fraunhofer FEP booth (No. 31) at ISAL.