Tomorrow, Tuesday March 29, we start out with the first Session of our Symposium EP1 Organic Excitonic Systems and Devices. The session runs under the title Organic Light-Emitting Devices (OLEDs). So clearly, we are looking to a collection of recent progress on the OLED technology, where the optimization of efficiency is in the central focus. Here are some keywords that will represent the content of tomorrow:
Enhanced emission of OLEDs
Bright NIR OLEDs based on high mobility polymers
Intrinsic degradation mechanisms in UV and blue OLEDs
Increased stability of TADF OLEDs
100% triplet harvesting in fluorescent OLEDs
Blue phosphorescent OLEDs
Absence of triplet up-conversion in anthracene based emitters
Afterglow OLEDs (a demonstration of biluminescence in OLEDs)
Origin and control of emitter orientation in OLEDs
Our invited speakers for this session are: Mark Thompson, Stephen R. Forrest, and Jang-Joo Kim.
A couple of impressions from our tutorial connected to the MRS Spring 2016 Symposium EP1: Organic Excitonic Materials and Devices: In short, the room has been packed with more attendees than chairs in the room. Chihaya Adachi started out giving us a complete overview on a class of materials for organic light-emitting diodes, he pioneered, namely thermally activated delayed fluorescence (TADF)-type emitters. He reflected on his initial reports on TADF in 2009, when nobody in the community cared about this concept, lacking competitive efficiency values at the time. Nowadays, these materials are TADF on par with phosphorescence in respect to device efficiency. Listening between the lines, we learned that up to date, the Adachi Lab counts more than 200 TADF molecules made – impressive.
After very limited coffee supply during the break, Stéphane Kéna-Cohan switched gears and gave us a very insightful introduction to the world of organic based lasers. Beginning with the very basics needed for understanding the concepts of lasers in general, we ended up learning the very current developments connected with laser research based on organic materials. The key potential here is seen for its high degree of possible integration, which is for instance important for bio-applications. When discussing the challenges remaining towards the demonstration of an electrically pumped organic laser, Stéphane Kéna-Cohan motivated where the threshold for electrical pumping roughly is using a back-on-an-envelope calculation, which actually fits on an envelope, as the picture below proves.
With the tutorial done, we are looking forward to the upcoming four days of regular symposium program. The sessions will reconvene at a different room: PCC North, 200 Level, Room 227 A. See you tomorrow.
Finally, the first ever MRS Spring Meeting in Phoenix, Arizona, is here in 2016. It runs from March 28 to April 1. My colleagues Malte C. Gather, Marc A. Baldo, Chihaya Adachi and I are excited to participate in this event with the Symposium EP1: Organic Excitonic Materials and Devices. We are looking forward to a full week of a packed, interesting, and diverse program.
We are happy to have Chihaya Adachi (Kyushu University) and Stéphane Kéna-Cohen (Ècole Polytechnique de Montréal) as instructors for the tutorial on board. We will hear in-depth introductions to OLEDs and Lasers, respectively. Come and join us tomorrow to kick-off our Symposium EP1 early with this half-day tutorial session. Here are the details:
Part I: Chihaya Adachi
The first segment will discuss the key properties of organic molecules important for the use in electroluminescent devices, i.e., organic light-emitting diodes (OLEDs). The fact that about 75% of the excitons are formed in an energetically distinct, nonradiative triplet state urges materials designers to come up with innovative solutions. There will be a detailed discussion of a very recent excitonic scheme: thermally activated delayed fluorescence (TADF), which Professor Adachi and his research team recently pioneered.
Part II: Stéphane Kéna-Cohen
This segment will begin with a review of basic laser physics in the context of organic lasers, briefly surveying state-of-the-art organic lasers and their applications. Electrically pumped organic lasing remains one of the open challenges in the field of organic electronics and the main difficulties toward achieving this goal will be discussed. The second half will cover a new type of laser, dubbed a polariton laser, which has the potential to drastically lower organic laser thresholds. The physics behind such polaritons will be discussed and some of the fascinating physics that have been observed (ballistic propagation, spontaneous vortices, superfluidity) will be described.
Just a brief reminder: The deadline for the abstract submission of the MRS Spring 2016 Meeting in Phoenix is approaching. It will close on October 15, 2016 (11:59 p.m. ET). If you are interested in organics, excitonics, systems, devices, etc., we would be happy if you consider our Symposium EP1: Organic Excitonic Systems and Devices. Please find the Call for Papers here. We have a great line-up if invited speakers covering broadly many exciting topics.
Together with my colleagues Malte C. Gather, Chihaya Adachi and Marc A. Baldo, I am organizing a symposium for the first ever MRS Spring Meeting in Phoenix next year (2016). The conference will run from March 28 to April 1. The topic of our Symposium EP1 is: Organic Excitonic Systems and Devices. We hope that this symposium will bring together the broad range of research and development in the field of organic and soft matter sciences that make use of the excitonic properties found in these materials.
Excitonic = exciting, right?
We are excited to receive your submissions for oral presentations and posters. Click on the Call for Papers image, to get a larger view. We already have a great assembly of invited speakers for this meeting.
The abstract deadline is October 15th, 2015. Remember, no late submissions can be considered for acceptance, so don’t be late with your contribution.
We also highly appreciate, if you spread the word!
In a new review article (Recent advances in light outcoupling from white organic light-emitting diodes) in the Journal of Photonics for Energy, my colleague Malte C. Gather (University of St. Andrews) and I summarize the recent efforts on the development of concepts for light outcoupling in white organic light-emitting diodes (OLEDs). Especially with respect to the complementary inorganic LED technology, it is extremely important to unlock higher external quantum efficiencies in OLEDs to stay competitive. Here, improving the outcoupling efficiency by far offers the largest margin (standard structures are at 20-30% of the internal efficiency maximum). The current status reveals that a universal solution with satisfying enhancement still waits to be found.