In 2018 the Fraunhofer FEP institute announced it is starting to offer a design kit that includes several flexible and transparent OLED lighting panels. The Monarch Kit includes several colored butterflies samples, and the researchers were kind enough to send us one such kit for a short review.
So first of all, these OLEDs look beautiful. They shine a beautiful uniform colored light and are very nicely done. There's not much functionality, but it shows the potential of flexible OLED lighting quite nicely.
Let's start with the technical details. To create these OLEDs, the Fraunhofer uses small molecule OLEDs deposited using an evaporation process in vacuum. These are segmented displays and the shapes (are defined with shadow masking - this is true for both the electrodes and the organic layers. Both the substrate and the barrier are made from PET. The organic materials are sandwiched between the two PET layers.
The Monarch OLEDs are made from commercially available OLED stack materials - and achieve a brightness of 500 - 1000 nits, and a transparency of 40-50%.
These OLED lighting panels are not mass produced by Fraunhofer - who is a research institute and not a commercial producer. The goal of the kit is to showcase the technology and the potential of segmented flexible and transparent lighting devices. The Fraunhofer, as part of the German "OLED Lichtforum", is working together with partners to bring these to series production, and is on the lookout for more companies to test the OLEDs and find commercial applications.
These OLEDs can be produced in the European LYTEUS PI-SCALE flexible OLED pilot line which can serve customers in their initial production volumes. In fact the view of the Fraunhofer FEP is that OLED lighting panels may be produced in standard formats and large volumes in the future - but there is also room for individual designs produced in small volumes - and the LYTEUS roll-to-roll processes may be key to enable such projects at controlled costs.
An interesting point is that the Fraunhofer uses Shadow masking - which can be seen as a limitation in terms of design freedom - but in fact the rich design experience and technologies enable the realization of unconventional designs, and the Fraunhofer is also developing advanced patterning techniques.
For more information on the Monarch Project and the Fraunhofer's OLED lighting capabilities and services, check out this brochure.