Periodic Reporting for period 2 - LEO (Low-cost / energy Efficient Oleds for lighting)
Période du rapport: 2016-07-01 au 2017-12-31
The second remarkable output of LEO project deals with the processing in solution of noble metal-free OLED emitter materials to reduce the environmental footprint of OLED technology (Hybrid OLED demonstrator). A smart adaptation of the novel Cynora TADF materials to inkjet printing and their integration into a dry-wet hybrid process chain was conducted within LEO and enabled the collective manufacturing of R, G and B OLED stripes that exhibit noticeable characteristics with a pronounced green and blue colour saturation and efficiencies up to 20Cd/A. The devices were produced in a laboratory platform, they demonstrate however dimensions (25 cm2) consistent with future lighting market needs.
In the same manner, a conformable hard coat was developed with success that better protects mechanically the OLEDs while preserving their emission characteristics, lifetime and a certain conformability. This novel encapsulation technology uses a sol-gel formulation specifically developed by CEA in collaboration with a French company, making this product close to commercialization. Last but not least, advanced top-electrodes based on smarter optical stack designs were developed and tested. They show well enhanced light emission (up to +60%) and better colour saturation that should benefit to ambient lighting but also display applications.
The LEO partners are already busy exploiting the project’s results. OSRAM, for instance, is focusing on process integration for both hybrid systems and metal-based OLEDs in automotive applications and special applications in general illumination. ArcelorMittal keeps on developing new materials and coatings based on R2R process technologies, as implemented in LEO, to produce advanced steel foils for printed electronics applications. Cynora is providing state-of- the-art TADF materials to worldwide leading panel makers, and CEA notably aims to transfer its encapsulation knowledge to both OLED and photovoltaic device manufacturers. Unexpected applications are also emerging beyond lighting. These include conformable OLED panels for aeronautics (patent pending), as well as display applications requiring higher image contrast than the conventional glass cover approach.