Our recent paper together with our colleagues at the Leibniz Institute of Polymer Research Dresden (IPF), is featured in Advanced Science News. This work discusses a novel way to achieve thermally activated delayed fluorescence in polymers through an extension of the HOMO conjugation, which ultimately leads to a smaller splitting between singlet and triplet excited charge transfer states. The paper can be found here: Conjugation-Induced Thermally Activated Delayed Fluorescence (TADF): From Conventional Non-TADF Units to TADF-Active Polymers.
In a recent collaboration with our colleagues at the Leibniz Institute of Polymer Research Dresden (IPF), we have developed polymers that show thermally activated delayed fluorescence (TADF) properties with high efficiency. This work has now been published in Advanced Functional Materials under the title: Conjugation-Induced Thermally Activated Delayed Fluorescence (TADF): From Conventional Non-TADF Units to TADF-Active Polymers. Interestingly, the monomer building block does not show TADF but rather only phosphorescence. Hence, the TADF property is induced as a consequence of increased conjugation during polymer formation. Ultimately, the singlet-triplet splitting is reduced in the polymer to allow for TADF. The emitter shows sky-blue emission with roughly 70% PLQY. This report includes the synthesis of the monomer and polymer materials, quantum chemical calculations and a detailed photo-physical characterization.
Published in the April 2014 issue of Nature Photonics, the group of Chihaya Adachi report on highly efficient blue OLEDs based on the novel thermally activated delayed fluorescence (TADF) concept (Efficient blue organic light-emitting diodes employing thermally activated delayed fluorescence). This is yet another important and equally impressive milestone in the OLED field, which puts these novel emitters on par with phosphorescence emitting molecules (at least with respect to their efficiency).
Along with the paper mentioned above, I express my thoughts about this development in a Nature Photonics News & Views feature. Read it here: Phosphorescence meets its match. I expect to see white TADF OLEDs coming in 2014.
Today will be our ‘device focus’ day. We are starting out in the morning with high performance OLEDs, both monochrome and white. Our first invited talk, given by Wolfgang Bruetting, will put the spotlight on emitter orientation and it’s impact to light outcoupling in OLEDs. Junji Kido will present their latest efforts on high performance white OLEDs for general lighting – it’s gonna be bright. After his talk, we switch gears a little with Russ Holmes’ talk on recombination in OLEDs, answering the question, which morphology and material composition is best.
After lunch break, Zheng-Hong Lu will put another focus on the impact of the device complexity on its overall performance (Is simpler also better? See yourself). Later this afternoon, Klaus Meerholz will talk about light-emitting organic memories – less of a mainstream topic, which makes it even more exciting to see the results.
So check the program, adjust your schedule and come along. We are looking forward to see you.
PS: Our today’s contributed candy is the presentation of Matthew S. White, where we will see the thinnest OLEDs ever made (they are flexible, stretchable, and deformable).