“Research is four things: Brains with which to think, eyes with which to see, machines with which to measure and, fourth, money.”
Albert Szent-Györgyi, Nobel Laureate in Physiology and Medicine
Experiences of Supported Students
My research area is in interfacial electron dynamics at hybrid metal-organic heterostructures, which perfectly fits to the fundamental research topics of ICASEC. In this field, I did a PhD at the TU Kaiserslautern in 2014. After two parental leaves, I was searching for new opportunities: I wanted to quickly resume my research efforts in the field of energy studies, and also explore new possibilities to build-up a scientific career. Here, ICASEC did help me with fast, uncomplicated and straightforward funding of my position. Meanwhile, I was successful in achieving own funding through the Dorothea Schlözer Program at the University of Göttingen.
I am carrying out my experiments in the research group of Prof. Mathias from the I. Institute of Physics. We are combining new concepts in MHz repetition rate extreme ultraviolet generation with new concepts in spatially resolved time-of-flight momentum microscopy. This tabletop setup enables unprecedented momentum-, energy- and time-resolved studies of the electronic degrees of freedom of materials. Using these techniques, we want to study electron dynamics (time- and angle-resolved photoelectron spectroscopy), orbital dynamics (time-resolved orbital tomography) and structural dynamics (time-resolved photoelectron diffraction) of correlated systems.
Using the latter enables observing structural changes during and after an extrinsic excitation. As the structure of a molecule/material is directly relevant for its functionality due to the electron-lattice correlation, this method gives direct access, for instance, to energy transfer, phase transitions, as well as multistep chemical processes. During my Dorothea Schlözer postdoc we will focus at establishing time-resolved photoelectron diffraction as a tool to investigate the structural dynamics of correlated systems like molecule/metal interfaces or 2D transition-metal dichalcogenide materials.
To turn graphene into a true candidate material for future electronic device applications one important issue is controlling the Dirac point by doping. This will allow to tailor the charge carrier density, i.e. the electronic properties of a graphene sheet by lateral band structure engineering. Within this project we will explore the perspectives of ion beam implantation for controlled doping of graphene. This is a joint project in close collaboration with the group of Prof. Hans Hofsäss (University of Göttingen). Our common goal is to maximize the degree of doping while minimizing the magnitude of charge carrier scattering by lattice defects. More specific, we will explore the limits of low energy ion beam implantation by optimizing the preparation process as well as by searching for alternative dopant species. My task within this joint project is the characterization of these samples by room and low temperature scanning tunneling microscopy and spectroscopy. In order to additionally analyse defects on the nanoscopic scale, Kelvin probe force microscopy (KPFM) will be used to determine transport parameters on a mesoscopic scale.
I studied physics in Göttingen and finished my master’s thesis about structural and transport properties in graphene on the atomic scale in July 2017 in the group of Martin Wenderoth. Thanks to support by ICASEC I was able to directly pursue my research in the field of transport in graphene within a PhD thesis.
The development of the theoretical description and understanding of gas-surface interactions is of great interest for many important industrial processes. In particular, the dynamics of such interactions might play a crucial role in the processes. In this context, the validity of the commonly employed Born–Oppenheimer approximation (BOA) is an important issue, since although satisfactory agreement between electronically adiabatic simulations and experiments has been achieved in some cases, there is clear evidence of relevant amount of electron-hole (e–h) pair excitations being created when chemical compounds interact with metal surface.
During my joint PhD among the University of the Basque Country and the University of Bordeaux, we studied the effect of e–h pair excitations in non thermal recombination processes on metal surfaces (Eley-Rideal and Hot-Atom recombinations). Since June of 2017, thanks to the support of ICASEC to start a new project, I am in Prof. Alec Wodtke’s group “Dynamics at Surfaces” as a Postdoc. We are developing a new tool to describe theoretically thermal recombination processes on surfaces going beyond the BOA and accounting for electronic excitations. When it comes to surface reactions at or near thermal equilibrium that involve high reaction barriers, transition state theory (TST) is undoubtedly the most successful and widely employed theoretical approach. The main goal of this project is the development of TST introducing non-adiabaticity within the dynamic factor to a posteriori evaluate BOA’s validity in thermal desorption processes from metal surfaces.
I received my PhD degree (Supervisor: Prof. Rainer Beck) in chemical engineering in 2012 from École Polytechnique Fédérale de Lausanne (EPFL) in Lausanne, Switzerland. Afterwards I moved to Max-Planck Institute for Biophysical Chemistry in Göttingen to start my postdoctoral research in Prof. Alec M. Wodtke’s group. The research project is to develope an ultra-sensitive mid-infrared emission spectrometer using a new emerging single-photon detector technology ‒ superconducting nanowire single-photon detectors (SNSPDs) which opens a path to a wide range of applications where extremely high sensitivity and excellent temporal resolution is required for molecular spectroscopy. The goal of the research is to study dynamics of molecular vibrational energy flow at solid surfaces. In other words, to answer questions such as: “what is the fate of molecular vibration excitation at surfaces?”, “how long will the vibration survive?”, and “what are the vibrational energy flow paths?” With the support of ICASEC, I could extend my postdoc stay in Gottingen, which enabled me to finished two manuscripts and allowed an overlap with my successor for technology transfer.
My name is Jascha Lau and I have studied chemistry at the University of Göttingen. For my master’s thesis in 2016, I got the opportunity to work in the Surfaces, Microstructure and Fracture Group at the Cavendish Laboratory (University of Cambridge, UK) for six months.
I worked on a machine designed for quasi-elastic helium atom scattering with exceptional energy resolution, called helium-3 spin-echo spectroscopy, which I used to study the molecular diffusion of cyclooctatetraene adsorbates on a Cu(111) surface. It allowed me to get a profound understanding of various aspects important to surface science, e.g. surface diffusion and phonons, and I developed my experimental and technical skills necessary for working on such complex experiments. All that has proven very useful for my current PhD project in the group of Prof. Wodtke in Göttingen. It involves the study of vibrational energy transfer between molecules adsorbed at surfaces by means of time-resolved laser-induced infrared fluorescence.
With the support from the ICASEC, I was able to fully focus on my research. In addition, I got the chance to present the results of my Master’s thesis at the Third International Conference on Scattering of Atoms and Molecules from Surfaces in Bergen, Norway, which made it possible to share and discuss my results with other scientists working in this field.
John Henri Gaida
I am studying Physics in Göttingen and did my bachelor thesis in 2015 in the group of Claus Ropers on Ultrafast Hot Carrier Photoluminescence in Graphene. During my master studies I wanted to gain experience abroad and so I approached Prof. Ropers about it. He told me about ICASEC’s Boomerang program and also suggested some suitable groups for a short research visit before my master thesis. I decided to ask the group of Giulio Cerullo and Dario Polli if I could come for a three-month research stay at the Politecnico di Milano, Italy, which are well known in the area of ultrafast laser science.
Starting from April 2015 I had the chance to build an interferometer developed in their group which is based on birefringent crystals. We used it to give a standard time correlated single photon counting (TCPSC) setup for time-resolved fluorescence detection spectral resolution via a Fouriertransform approach. We successfully investigated test samples of fluorescent dyes and a biologically relevant photosynthetic light-harvesting complex. The results of my stay are summarized in a paper published in Optics Express – Time- and frequencyresolved fluorescence with a single TCSPC detector via a Fouriertransform approach.
Not only did I acquire new skills in the lab and got to know another Research group, but I also made good new contacts. Now I am finishing my master’s studies with a thesis in the group of Claus Ropers where I am working on an experiment to resolve ultrafast magnetic dynamics with an Ultrafast Transmission Electron Microscope (UTEM).
International Research Visits
My name is Jana Lücken and I am a PhD student in the group of Prof. Meyer in the Inorganic Chemistry Department at the University of Göttingen working on water oxidation catalysts. In 2016, ICASEC gave me the financial support to spend three months in the group of Prof. Llobet at the Institute of Chemical Research of Catalonia (ICIQ) in Tarragona, Spain, a world-leading institute in catalysis research and an ICASEC partner institute. The ICIQ provided an ideal environment to conduct the desired photocatalytic measurements and get a deeper insight into the electrocatalytic behavior of the ruthenium catalysts. Additionally, with the expertise of Prof. Llobet and his group members I was able to significantly improve my knowledge of the field of catalytic water oxidation. Currently, I am finishing off my ruthenium project and trying to focus more on water oxidation catalysts with cheap and earth-abundant 3d-metals.
International Conference Visits
Svenja M. Janke
When I attended the GRS and GRC “Dynamics at Surfaces” in Newport, Rhode Island, in 2015, I was a Ph.D. student in the research group of Prof. Dr. Alec Wodtke. Both the seminar and the conference provided me with opportunities to broaden my knowledge of the field, to obtain very helpful input to further my own research and to establish important contacts for my future career. Furthermore, I had the chance to present a poster about my own research to the community, for which I received one of the conference’s poster awards. After the conference I was able to visit two leading research groups, namely the group of Prof. Dr. John Tully at Yale and the group of Prof. Dr. Jens Nørskov at Stanford. An additional summer school followed the latter visit at the same place. Both visits were excellent opportunities to connect with scientists of high renown, to learn more about their research and to look for possibilities for postdoctoral research. All in all, I had many excellent opportunities to present my own research, to shape my scientific future, to learn about future research directions and to meet leading researchers in the field of surface Dynamics.
Now I am a postdoctoral researcher on a DFG postdoctoral fellowship in the group of Associate Professor Dr. Blum at Duke University. My work here is focused on the computational design and prediction of the structure and properties of new semiconducting organic-inorganic hybrid materials.
Attending the GRC “Dynamics at Surfaces” in Newport, Rhode Island gave me the opportunity to meet, and talk science with, the leading researchers in surface dynamics. This broadened my knowledge of the field and helped me make contacts that will be useful throughout my career.
I am currently an assistant professor at KTH – Royal Institute of Technology, in Stockholm, Sweden, where I am setting up my own group to do surface reaction dynamics with the goal of understanding how and why reactions happen on surfaces.
I’m a PhD student in Prof. Dr. Meyer’s working group and presented a poster at the EuCheMS Inorganic Chemistry Conference (EICC-4) 2017 in Copenhagen on “Iron Complexes of Macrocyclic Tetracarbenes: Robust Scaffolds for the Transformation of Small Molecules”. The ICASEC International Conference Visits program enabled me to participate in this event and discuss my results with experts in the field of energy-related research. Additionally, the EICC-4 presented valuable networking opportunities.
In July 2017, ICASEC gave me the financial support to attend the 2nd International Solar Fuels Conference including the preceding Young Conference in San Diego, USA. Here, I was able to present my collected results on ruthenium water oxidation catalysts in the form of a poster and get valuable feedback from experts in the field of artificial photosynthesis. Especially the young conference was very productive as it allowed me to discuss my research with other PhD students and postdocs with a similar scientific background as myself.
My PhD project in Prof. Alec Wodtke’s group “Dynamics at Surfaces” focuses on the interaction of highly vibrationally excited molecules with metal surfaces. When scattering a molecular beam of CO(v = 17) from an atomically clean Au(111) surface, we observe vibrational relaxation which is thought to proceed via an electron transfer from the metal to the molecule. The comparison of different molecule/surface systems indicates that the degree of this electronically non-adiabatic interaction scales with the work function of the metal and the vibrational state dependent electron binding energy of the molecule. At the Gordon Research Seminar on “Dynamics at Surfaces” in Newport, I had the chance to discuss these findings with young researchers from all over the world. Immediately after the Seminar, I took part in the Gordon Research Conference on “Dynamics at Surfaces”, where leading scientists of the field reported on their latest results. Intense and fruitful discussions with theoreticians and experimentalists at the poster sessions were very stimulating and promoted the understanding of mechanisms behind the phenomena that we observe in the laboratory. Thus, I gratefully acknowledge the financial support by ICASEC which allowed me participating in this conference.
The ICASEC International Conference Visits Program allowed me to attend the Gordon Research Conference “Dynamics at Surfaces” in Newport in 2015. The invited speakers and especially the poster sessions encouraged me to get an overview of the state-of-the art experiments and theory in my field. Combined with the superb scientific atmosphere this further increased and broadened my interest in the field and thus helped me prepare for the following experiments.