The tutorial introduced attendees to organic light-emitting diodes (OLEDs) and organic laser systems, both with high relevance to Symposium EP1. While both concepts make use of organic materials, the toolboxes to understand all the details are very different.
Part I: Chihaya Adachi
The first segment discussed 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 was 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 began 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 were discussed.
The second half covered a new type of laser, dubbed a polariton laser, which has the potential to drastically lower organic laser thresholds. The physics behind such polaritons were discussed and some of the fascinating physics that have been observed (ballistic propagation, spontaneous vortices, superfluidity) were described.
- Chihaya Adachi, Kyushu University
- Stéphane Kéna-Cohen, École Polytechnique de Montréal