Research Center for Organic Electronics ＞ {Finished} The 54th ROEL Lecture Session

On February 22nd, the 54th ROEL Lecture Session was held in Seminar Room ("Hata" Hall) on the 3rd floor of International Bussiness Development Research Center.
We invited Dr. Matthew White from Johannes Kepler University of Linz as a guest speaker and he gave a presentation entitled "Current research topics from LIOS: “Hydrogen bonded organic semiconductors” and “Ultrathin organic electronics.""
More than 20 researchers and students attended to the lecture and it finished in success.

Seminar room during the lecture

Dr. Matthew White,
Johannes Kepler University of Linz

　　The first portion of this lecture will challenge some conventional wisdom regarding the design of both organic semiconductors and organic opto-electronic devices. Our recent work shows how small molecules that lack the high degree of intra-molecular conjugation typically associated with “good” organic semiconductors can give surprisingly good carrier transport and air stability. The π-overlap between these molecules is enhanced by the forced molecular orientation associated with hydrogen bonds. Thus, transport is anisotropic, but gives very reasonable mobility. The good molecular packing has strongly affects both the absorption and luminescence of the molecules. We further show, that hydrogen bonded organic semiconductors can be used in single-material solar cells, producing over 1 mA/cm2 in the absence of a heterojunction.
　　Changing topics, I will show our recent developments in the field of ultrathin organic electronics. Organic solar cells and LEDs are inherently thin, and it is frequently claimed that low-weight and flexibility are natural advantages of the technology. However, most substrate materials are much thicker and most flexible foils are 100 µm, whereas the active device is only 200 nm thick. Therefore, the mechanical properties of weight and flexibility are entirely determined by the substrate. We show a method for processing organic PV and LEDs directly onto foil substrates that are less than 2 µm thick. This allows continuous operation of devices under extreme deformation. We can crumple the films, bend them to radius of under 5 µm, and even stick them to elastomeric tape to form stretchable PLEDs and OPV cells. Their weight becomes negligible (only 4 g/m2), resulting in ultrathin OPV with the highest specific weight (W/kg) of any photovoltaic technology.

*We will also have a short presentation session given by students in the same room right after this lecture.

Time/Date	Feb. 22nd (Fri.) PM1:00 - PM2:30
Location	Seminar Room ("Hata" Hall) on the 3rd floor of International Bussiness Development Research Center
Lecturer	Dr. Matthew White, Johannes Kepler University of Linz
Subject	Current research topics from LIOS: “Hydrogen bonded organic semiconductors” and “Ultrathin organic electronics"