35. Erfinderlabor: Scientific curiosity of the next Generation

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Hessen’s young MINT scientists conduct research on hydrogen and renewable energies within the SFB 1083 and Philipps University Marburg

The 35th Inventors’ Lab (Erfinderlabor) of the Center for Chemistry (Zentrum für Chemie, ZFC) has successfully entered its finale. This year’s event was once again organized by the ZFC in cooperation with the Philipps University of Marburg and Elkamet and supported by other renowned cooperation partners such as the SFB 1083 and LEA (Hesse State Energy Agency).

The practice-oriented workshop not only offers valuable career orientation on career opportunities in the MINT environment (mathematics, informatics, natural sciences and technology), but also always addresses a current topic of high socio-political and economic relevance. The focus of this year’s Inventors’ Lab was on renewable energies and hydrogen.

The participants were selected from 126 female and 111 male students from 99 Hessian schools, the German School Seoul International and the German Embassy School New Delhi. The sixteen students in four teams dealt with different issues in the context of the energy transition in different research groups, which are part of the SFB 1083. The topics were the use of TiO2 in photovoltaics, the hydrogen storage in organic molecules as well as the functioning of batteries and energy storage materials. Finally, the usage of raspberries in solar cells was investigated.

On May 17, the participants presented their research results on the topic of the energy transition to young people in the career orientation phase as well as representatives from research, business and politics at a virtual closing event. Armin Schwarz, Hessian Minister for Culture, Education and Opportunities, praised the “outstanding achievements” of the participants and described the content covered in the inventors’ lab as “directly relevant to the scientific and economic development of the state”.  Prof. Dr. Sabine Pankuweit also emphasized: “Renewable energies and hydrogen are topics that could not be more topical.” The Vice President for Equal Opportunities and Career Development at Philipps-Universität Marburg joined the virtual closing event directly from a research laboratory.

The experts were impressed by the technical curiosity and quick comprehension, but also by the motivation and team spirit of the young people. “The graphics were well designed and the results were presented scientifically correct,” said Dr. Johanna Heine from the SFB during the virtual closing event (https://www.youtube.com/watch?v=n1u0s7DYPmA).

The local project partner was the Chemikum Marburg represented by Dr. Christof Wegscheid-Gerlach. “The Inventors’ Lab exemplifies how scientific topics of the future can be communicated at the intersection of school and university, and thus how both levels of education can be interlinked.”

Contact

Dr. Christof Wegscheid-Gerlach
Philipps-Universität Marburg
SFB 1083 project Oe
Tel.: 06421 28-25843
EMAIL

 

Synthesis of 2D Gallium Sulfide with Ultraviolet Emission by MOCVD – Publication by A4 (Gottfried), A5 (Volz), A14 (Volz) and B2 (Chatterjee) in Small

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In a joint study of the projects A4, A5, A14 and B2, the two-dimensional growth of GaS on sapphire by MOCVD was successfully studied and the layers were characterized using a wide variety of techniques.

2D materials exhibit the potential to transform semiconductor technology. Their rich compositional and stacking varieties allow tailoring materials’ properties toward device applications. Monolayer to multilayer GaS, with its ultraviolet band gap, which can be tuned by varying the layer number, holds promise for solar‐blind photodiodes and light‐emitting diodes as applications.

In this cooperative study of different groups within the SFB 1083, the one‐step synthesis of 2D GaS is introduced via MOCVD (metal–organic chemical vapor deposition) on sapphire substrates. The pulsed‐mode deposition of industry‐standard precursors promotes 2D growth by inhibiting the vapor phase and on‐surface pre‐reactions. High resolution STEM imaging proves the ML nature of the GaS, but also shows a covalently bonded Ga adlayer on the sapphire, which plays an important role in mediating the epitaxial relationship of the GaS ML with respect to the sapphire substrate. The structural and chemical composition determined by electron microscopy related techniques are corroborated by XRR, XPS, Raman spectroscopy and PL and confirm a 2D nucleation of GaS on sapphire, which is an intricate balance between surface wetting, Ga droplet formation and strain-induced change of atomic spacing as well as van der Waals distances.

Growth model of the flow modulated GaS deposition.

The results highlight the adaptability of established growth facilities for producing atomically thin to multilayered 2D semiconductor materials, paving the way for practical applications.

Publication

O. Maßmeyer, R. Günkel, J. Glowatzki, P. Klement, B. Ojaghi Dogahe, S.R. Kachel, F. Gruber, M. Müller, M. Fey, J. Schörmann, J. Belz, A. Beyer, J.M. Gottfried, S. Chatterjee, K. Volz
Synthesis of 2D Gallium Sulfide with Ultraviolet Emission by MOCVD
Small (2024) 2402155 DOI:10.1002/smll.202402155

Contact

Prof. Dr. Kerstin Volz
Philipps-Universität Marburg
SFB 1083 project A5, A14, B13
Tel.: 06421 28-22297
EMAIL

Probing electron-hole Coulomb correlations in the exciton landscape of a twisted semiconductor heterostructure – Publication by B9 (Malic) in Science Advances

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In a joint study including the experimental group of Stefan Mathias from the University of Göttingen and the theoretical group of Ermin Malic the ultrafast charge transfer in twisted van der Waals heterostructures was studied.

Cover of Science Advances Volume 10 Issue 6. An ultrashort light pulse breaks apart an exciton, comprised of an electron bound to an electron hole.

In two-dimensional semiconductors, cooperative and correlated interactions determine the material’s excitonic properties and can even lead to the creation of correlated states of matter.

In a joint experiment theory study, the research groups of Stefan Mathias (Göttingen) and Ermin Malic (Marburg) have studied the ultrafast charge transfer in twisted van der Waals heterostructures.  The researchers found that the transfer of an excitons hole across a type II band-aligned heterostructure leads to an unexpected sub-200-femtosecond upshift of the single-particle energy of the electron being photoemitted from the two-particle exciton state. While energy relaxation usually leads to an energetic downshift of the spectroscopic signature, is was shown that this upshift is a clear fingerprint of the correlated interaction of the electron and hole parts of the exciton.

In this way, time-resolved photoelectron spectroscopy is straightforwardly established as a powerful method to access electron-hole correlations and cooperative behavior in quantum materials. The joint work highlights this capability and motivates the future study of optically inaccessible correlated excitonic and electronic states of matter.

Publication

J.P. Bange, D. Schmitt, W. Bennecke, G. Meneghini, A.A. Al Mutairi, K. Watanabe, T. Taniguchi, D. Steil, S. Steil, R.T. Weitz, G.S.M. Jansen, S. Hofmann, S. Brem, E. Malic, M. Reutzel, S. Mathias
Probing electron-hole Coulomb correlations in the exciton landscape of a twisted semiconductor heterostructure
Sci. Adv. 10 (2024) eadi1323 DOI:10.1126/sciadv.adi1323

Contact

Prof. Dr. Ermin Malic
Philipps-Universität Marburg
SFB 1083 project B9
Tel.: 06421 28-22640
EMAIL