Preview: Two sessions on Wednesday

Tomorrow, Wednesday March 30, we have two sessions at our Symposium EP1: Organic Excitonic Systems and Devices.

EP1.2: Organic Emitters

The morning focus will be on the emitters itself, where we will here recent progress on various molecular concepts for high performance luminescence. This will include the fundamental studies that excel our current understanding of these emitters. Some things that we will see:

  • Design rules for TADF emitters
  • Crystalline OLED emission layers for nearly perfect emitter alignment
  • Investigation of exciplex emission (electric field dependence and charge separation)
  • Nickel-Tetra-Mesityl-Porphoyrin photophysics
  • Platinum complexes for high efficiency, color pure blue OLEDs
  • Control of molecular orientation
  • TADF emitters for LECs and OLEDs
  • Biluminescence for optical sensing
  • Photophysics of H- and J-aggregates

Our invited speakers of the morning are: Andrew Monkman, Wolfgang Brütting, and Frank Würthner.

EP1.3: Organic Lasers

In the afternoon we switch gears – Its laser time. With the basis of the laser tutorial we had on Monday, we should be all set for some interesting contributions related to laser physics with organics. Important: Due to a serious illness of one of our speakers, the program of the first part of the EP1.3 session has been updated. We will start at 2:00pm rather than the originally planned time of 1:30pm. Please refer to the online program for the latest updates!

Here are some details to the post-lunch session:

  • Condensate physics with organic polaritons
  • Tunable, narrow line width solid-state lasers
  • LED-pumped organic lasers (planar integration) based on luminescent concentration
  • Self-assembled colloidal lasers
  • Low threshold up-converted laser
  • Strong coupling in organic microcavities
  • Solvent nano imprint lithography of polymer lasers
  • Photoluminescence enhancement in nano cavities

Our afternoon invited speakers are: Stéphane Kéna-Cohen and Alexander J. Kuehne.

Again, a lot of cool and interesting things to look forward to. See you tomorrow!

Packed tutorial on OLEDs and Lasers

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 Monday_Tutorial_SKC3and 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.

Monday_Tutorial_SKC2With 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.

MRS Spring Meeting 2016 in Phoenix: Starting out with a tutorial

Finally, the first ever MRS Spring Meeting in Phoenix, Arizona, is here in 2016. It runs from March 28 to April 1. MRS Spring 2016My 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.

But before the symposium even starts, we have a tutorial to offer: Tutorial EP1: Organic Excitonic Materials and Devices – OLEDs and Lasers. It will run tomorrow, Monday March 28 from 8:30 am to 12 pm. Location is PCC North, 100 Level, Room 125 B.

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.

See you tomorrow!