TU Braunschweig (IHF)

The group of Prof. Wolfgang Kowalsky (Institute for High-Frequency Technology, TU Braunschweig and Kirchhoff-Institute, Heidelberg University) at InnovationLab is part of the Competence Center Analytics. As such, we cooperate with the groups from Heidelberg University and TU Darmstadt.

The main focus of our research is the correlation between structure and function in organic (opto)electronic devices. We investigate

  • fundamental properties of doped organic semiconductors,
  • organic solar cells, and
  • surface modifications for applications in Organic Electronics.

Our main experimental tools are advanced electron microscopy and scanning probe microscopy and combinations thereof. You can find details under methods.

Our homepage gives a short overview on our ongoing research. For more detailed information please take a look at our publications. In case you are interested in working in our team or collaborating with us, please contact us directly.

Doped organic semiconductors

How does the morphology of a host:dopant system effect its doping efficiency? We are working on answering this and related questions in close collaboration with our partners from Heidelberg University (Prof. Annemarie Pucci, Prof. Rasmus Schröder) and TU Darmstadt (Prof. Wolfram Jaegermann). We investigate in particular the model system CBP:MoO3.
Our activities in the field of doped organic semiconductors are funded by the Federal Ministry of Education and Research (BMBF) within the project InterPhase (FKZ 13N13656).

Interface modifications for organic electronics

Surfaces and interfaces have tremendous influence on the performance of electronic devices. That might be even more so for organic electronics than for silicon based technologies. Thus, the controlled modification of organic/inorganic and organic/organic interfaces is of high importance. One approach we are pursuing in this direction is making use of self assembled monolayers to control the barrier height and wettability of organic/inorganic interfaces.
Our activities in the field of interface modifications are funded by the BMBF within the project InterPhase (FKZ 13N13656).

 

Correlated electron and scanning probe microscopy

We have an integrated SEM-AFM system (BRR by Zeiss/DME) that combines a Crossbeam Auriga electron microscope (SEM and FIB, Zeiss) with a scanning probe microscope (DME). This combination enables us to perform experiments that would be impossible using the components separately.

 

Scanning probe microscopy (SPM)

Besides the SPM incorporated in the SEM, we have two further SPMs for measurements in UHV and ambient. All SPMs are equipped for a variety of scanning probe techniques (e.g. scanning Kelvin probe microscopy), giving us not only morphological, but also electronic information on our samples with high spatial resolution.

 

Analytical Transmission Electron Microscopy (TEM)

We use our TEM (Zeiss Kronos) in close collaboration with the group of Prof. Rasmus Schröder (Heidelberg University) to study the structure function relationship in organic and hybrid solar cells. By means of spectroscopic imaging, we are able to distinguish even different organic materials by their respective electron energy loss spectra.

Electrical and Optical Characterization

We use the following instruments that are accessible at iL for electrical and optical characterization of our sample:

  • UV/VIS ellipsometer and absorption spectrometer
  • solar simulator
  • Kelvin-Probe
  • Photo-CELIV
  • temperature dependent electrical transport measurements

Postdoctoral Researchers

Christian Müller, Dr.

Postdoctoral Researcher
contact via email
Room: E 4.06

Phone: +49 (0) 6221 54 19 136 (iL)

Jean-Nicolas Tisserant, Dr.

Postdoctoral Researcher
contact via email
Room: E 4.01

Phone: +49 (0) 6221 54 19 163 (iL)

PhD Students

Marc-Michael Barf

PhD student
contact via email
Room: E 4.06

Phone: +49 (0) 6221 54 19 123 (iL)

Paul Heimel

PhD student
contact via email
Room: F 4.15

Phone: +49 (0) 6221 54 19 139 (iL)

Sebastian Hietzschold

PhD student
contact via email
Room: E 4.06

Phone: +49 (0) 6221 54 19 136 (iL)

Lars Mueller

PhD student
contact via email
Room: E 4.06

Phone: +49 (0) 6221 54 19 136 (iL)

Master & Bachelor

Israr Ahmed

Master student, Heidelberg University
contact via email
Room: E 4.06

Phone: +49 (0) 6221 54 19 136 (iL)

Ramos Bwalya

Master student, Heidelberg University
contact via email
Room: E 4.03

Phone: +49 (0) 6221 54 19 150 (iL)

Christian Willig

Master student, Heidelberg University
contact via email
Room: E 4.06

Phone: +49 (0) 6221 54 19 136 (iL)

Alumni

  • Jakob Bombsch (Bachelor & Master theses, 2017)
  • Stefan Brackmann (Master thesis, 2016)
  • Dominik Daume (Master thesis, 2012)
  • Dr. Daniela Donhauser (PhD thesis, 2013)
  • Helge Eggers (Master thesis, 2017)
  • Bernd Epding (Bachelor & Master theses, 2016)
  • Florian Friedrich (Bachelor thesis, 2016)
  • Martin Gebhardt (Master thesis, 2016)
  • Markus Gölz (Master thesis, 2013)
  • Tim Helder (Bachelor thesis, 2016)
  • Tobias Jenne (Master thesis, 2014)
  • Dr. Michael Kröger
  • Carsten Leinweber (Master thesis, 2013)
  • Benjamin Martini (Master thesis, 2012)
  • Alexander Müller-Brandt (Master thesis, 2013)
  • Dr. Diana Nanova (Master & PhD theses, 2015)
  • Marcel Plogmeyer (Bachelor thesis, 2015)
  • Viola Rädle (Bachelor thesis, 2016)
  • Seon-Young Rhim (Master thesis, 2017)
  • Dr. Rebecca Saive (PhD thesis, 2014)
  • Felix Schell (Master thesis, 2014)
  • Dr. Michael Scherer (Master & PhD theses, 2016)
  • Dr. Janusz Schinke (PhD thesis, 2014)
  • Dr. Ilja Vladimirov (Master & PhD theses, 2016)
  • Dongxiang Wang (Master thesis, 2016)