Chair News

Congratulations to Rishi on his new paper. "Alkyl Branching Position in Diketopyrrolopyrrole Polymers: Interplay between Fibrillar Morphology and Crystallinity and Their Effect on Photogeneration and Recombination in Bulk-Heterojunction Solar Cells" was published by "Chemistry of Materials"

To be found here.

From April to June 2017 I had the chance to work for 3 months with the Salleo Research Group at Stanford University. The research visit was financed in part by the cfaed INSPIRE grant and in part by the Graduate Academy through a travel grant for short-term research stays abroad. During my time in the group I was trying to shed light on the charge carrier transport in thin films of semiconducting polymers synthesized as part of the Organic/Polymer Path in collaboration with the Leibniz Institute for Polymer Research.  

The main reason for my visit of the group was the application of charge-modulation spectroscopy to our polymers. This technique has only been established in a few research groups around the world and gives information about the degree of freedom charge carriers have close to the semiconductor/dielectric interface based on the optical absorption of the carriers. The results will help us optimizing the device performance of field-effect transistors.

Furthermore, right next to Stanford University is the Stanford Synchrotron Radiation Lightsource, a Department of Energy user facility for very bright electromagnetic radiation. During my 3 months I was lucky enough to get multiple days and nights at the facility to investigate the film structure of our materials by x-ray scattering techniques. This allows us to correlate the structural and electronic properties of our semiconducting polymers.

One of our recent scientific pursuits included a visit of Prof. Stefan Mannsfeld, Postdoc Mike Hambsch and PhD student Rishi Shivare to the Synchrotron Light Source (ELETTRA) based in Trieste, Italy. The main motivation to visit such a research facility is the opportunity to work with intensely bright x-ray radiation.

In our case, we examined a wide range of organic semiconductors, using wide and small angle x-ray scattering. It lets us probe molecular and mesoscale structure of molecules and better understand how structural modifications affect device performance (for example in organic field effect transistors and solar cells). Doing experiments at a synchrotron is truly a unique experience, it is fascinating to see hundreds of scientists working round the clock.

© S. Geise
More images to be found here: TU Dresden-Absol(E)vent-Rückblick16

Organized by the network “Absol(E)vent’ the cfaed - Chair for Organic Devices hosted an event to present “Printable solar cells, OLEDs and transistors” to a group of 20 former members of TU Dresden. After a little introduction of Prof. Stefan Mannsfeld and Prof. Sebastian Reineke on the topic there was a tour through the laboratories at the historic “Bienert-Villa” to show printable electronic on flexible materials. It was a successful event with a lot of interesting questions and discussions and a good opportunity to show our scientific work.