Rainer H. Fink

Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), , 91058 ERLANGEN, GERMANY
E-mail: rainer.fink@fau.de  

Fresnel-zone plate (FZP) based microspectroscopy in the soft x-ray regime has become a widely used technique in thin film studies. The spectroscopic fingerprint in NEXAFS is combined with spatial resolutions on the order of 35 nm. We have suc-cessfully employed scanning transmission x-ray microspectroscopy (STXM) on vari-ous organic thin film systems to evaluate structure-property relationships in ultrathin organic films. For instance, we studied organic photovoltaic films prepared by alcoholic polymer:fullerene nanoparticle inks [1]. In-operando studies were employed to inves-tigate the electronic structure within the active channel of organic field-effect transistors (OFETs). The gate effect shows small variations in the unoccupied density of states (UDOS) thus opening the channel for charge transport. Most recently, we could suc-cessfully demonstrate that STXM can reach resolutions below 10 nm. Breakthrough came from ultimate resolutions in FZP fabrication using ALD and the zone-doubling technique yielding structure sizes on the order of 7 nm [2].    

References
[1]C. Xie, et. al, Nat. Comm. 9 (2018) 5335; C. Xie, et. Al., , ACS Applied Mat. & Interfaces 10 (2018) 23225.
[2]B. Rösner, F. Koch, F. Döring, J. Boesgra, et al., Microel. Eng. 191 (2018) 91.  

Biography
Rainer Fink studied Physics at the University of Konstanz/Germany. He was research assistant at Uppsala University/Sweden and the University of Würzburg/Germany. Since 2002 he is full professor for Physical Chemistry at the FAU Erlangen-Nürnberg/Germany. He has a strong expertise in the development and use of ultimately resolving x-ray based microscopies. The applications range from organic hybrid materials and polymer films to ultrathin organic films prepared from functionalized molecules. Besides, he coordinates students exchange pro-grammes between FAU and Chinese universities  

Location: Conference Room 103, Office Building
Time: 3:45 pm, April 15, 2019