In a bilateral resarch project on "Electron Spins as Probes for Understanding Energy Storage Materials based on Nitroxyl-containing Polymers", which is funded by the Deutsche Forschungsgemeinschaft and the Russian Science Foundation , we will develop a comprehensive understanding of the redox processes occurring at the electrodes in Organic Radical Batteries upon charging and discharging. For this purpose we are planning to develop and apply tailor-made techniques based on Electron Paramagnetic Resonance as well as Electrically Detected Magnetic Resonance spectroscopy. We are very much looking forward to intensifying our collaboration with Prof. Oleg Levin and his colleagues at the Saint Petersburg State University.
Oct 19, 2021
We are looking for a PhD student who will be participating in a bilateral German/French network project ( MARS ) on the development of magnetic resonance techniques for studying energy materials. The PhD project involves the investigation of Singlet Fission in organic semiconductors using spin-sensitive techniques. The job advertisement including details on how to apply can be found here (application deadline: 27.09.2021).
Sep 06, 2021
In collaboration with collegues from the Cavendish Laboratory at the University of Cambridge as well as from the University of Heidelberg we have published an article on singlet fission observed in novel, particularly stable organic semiconductors in Nature Communications . Among other techniques we have used Optically Detected Magnetic Resonance (ODMR) spectroscopy to study these materials, which hold promise for next-generation devices for optoelectronic applications.
Mar 09, 2021
Together with scientists from the Saint Petersburg State University we have recently published an article in the journal Batteries & Supercaps . In this paper we describe our joint work regarding the development and characterisation of novel electrode materials for organic radical batteries.
Nov 17, 2020
In a bilateral resarch project on "Magnetic Resonance Tools for Solar Materials" (MARS), which is funded by the Deutsche Forschungsgemeinschaft and the Agence Nationale de la Recherche , we will investigate the influence of electron spins on the photo-physical properties of organic semiconductors and thin perovskite films. For this purpose we are going to develop new spin-sensitive techniques. These will allow us to probe the properties of photo-excited states that appear in exciton fission systems and novel materials with broad impact on fundamental optoelectronics and its applications. The MARS project is a calloborative effort involving scientists from Paris ( Université Paris-Sud ), Versailles ( Université Versailles Saint-Quentin ), Grenoble ( Institut Néel ), Bayreuth ( Universität Bayreuth ) and Berlin ( Freie Universität Berlin ).
Sep 28, 2020
Claudia Tait's illustration describing the doping mechanisms in polythiophene was chosen as cover image for the September issue of the Journal of Physical Chemistry B .
Sep 03, 2020
As a result of an interdisciplinary collaboration with researchers from Humboldt-Universität zu Berlin , Helmholtz-Zentrum Berlin , Tokyo Institute of Technology , Soochow University and Bergische Universität Wuppertal we have recently published a joint article in the journal Advanced Science . In this paper we report on a detailed study regarding the increase in charge-carrier concentration in conjugated polymers using a novel dopant molecule.
Jul 06, 2020
An article on the detection and coherent manipulation of photoexcited quintet states in organic semiconductors was recently published in Physical Review X . This work is based on a collaboration with colleagues from the University of Cambridge as well as the University of Kentucky .
Jun 29, 2020
Together with scientists from the University of Potsdam , Humboldt-Universität zu Berlin , Carl von Ossietzky Universität Oldenburg and Georgia Institute of Technology we have recently published an article in the Journal of Physical Chemistry B . In this paper we describe our joint work regarding the doping mechanism in polythiophene in solution on a molecular level.
Jun 23, 2020
Ula Yasin received a prize for her poster on "Bias Dependence of Transient EDMR Signals from Organic Solar Cells" at the Spin Chemistry Meeting 2017 in Schluchsee. Congratulations!
Sep 21, 2017
An article on measuring the delocalisation of charge carriers in organic semiconductors was recently published in Physical Chemistry Chemical Physics . In this paper we describe measurements for determining the spatial extent of charge carrier wave functions in small organic molecules and conjugated polymers which can be used as absorber materials in organic solar cells. The experiments are based on Electron Nuclear Double Resonance (ENDOR) spectroscopy, a combination of EPR and NMR techniques. This work was realised in collaboration with colleagues from the King Abdullah University of Science & Technology in Saudi Arabia and the University of Massachusetts in Amherst.
Jan 18, 2017
In collaboration with collegues from the Cavendish Laboratory at the University of Cambridge as well as from the University of Kentucky we have published an article on singlet fission in organic semiconductors in Nature Physics . In this paper we report the observation of weakly and strongly coupled pairs of triplet excitons involved in the singlet fission process. We could identify these excitations by means of time-resolved Electron Paramagnetic Resonance (EPR) spectroscopy. Our work is highlighted by a "News and Views"-Article by Prof. Wasielewski published in the same issue of Nature Physics.
Oct 17, 2016
In collaboration with colleagues from the Light Technology Institute of the Karlsruhe Institute of Technology we have published an article on n-type doping of organic semiconductors in the Journal of Materials Chemistry A . In this paper we describe the use of sodium-doped contact layers for the efficient extraction of charge carriers in organic solar cells.
Sep 13, 2016
Felix and Jan will present our recent results on charge separation in organic solar cells at the Rocky Mountain Conference on Magnetic Resonance in Breckenridge in July.
Jul 14, 2016
An article on spin-dependent transport in thin-film silicon solar cells was published in Physical Review B . In this paper we describe how triplet excitons influence the photocurrent and can provide information about structural defects in solar cell materials.
Jul 07, 2016
Felix Kraffert received a prize for the best talk at the Young Researcher's Workshop in the framework of the DFG Priority Programme 1601 in Konstanz for his presentation on "Transient EDMR – A Novel Tool to Study Charge Transport in Organic Solar Cells". Congratulations!
Apr 15, 2016
Sebastian Linke starts his Master's Project on the Analysis of the Charge Carrier Dynamics in Organic Semiconductors.
Oct 10, 2015
Adrià Gràcia starts his Master's Project on Organic Solar Cells.
Oct 01, 2015
An article on transient electrically detected magnetic resonance (trEDMR) spectroscopy was published in Applied Physics Letters . In this letter we describe this new technique and its application to organic solar cells. In particular, we use trEDMR spectroscopy to study the influence of paramagnetic states on the photocurrent generated in polymer:fullerene solar cells.
Jul 27, 2015
The Berlin Joint EPR Laboratory (BeJEL) operated by HZB and Freie Universität Berlin has pulled in six of 27 subprojects within a DFG priority program to address “New Frontiers in Sensitivity for EPR Spectroscopy – from Biological Cells to Nano Materials” ( press release ).
May 27, 2015