Lars Klemeyer

Lars Klemeyer joined our lab in 2018 for his bachelor thesis in nanoscience on the nucleation and growth of ferroelectric thin films, studied by total X-ray scattering, in cooperation with DESY. During his master‘s, he joined the lab of Jiaxing Huang at Northwestern University (in 2019) and the Group of Serena de Beer at MPI for chemical energy conversion (in 2020). After finishing his master thesis on the investigation of nanostructured transition metal sulfides by means of X-ray spectroscopy in 2021, he continued his research as a PhD student in our lab.

In his research, he resolved the emergence of electronic- and atomic structure during the solvothermal synthesis of ZnS nanomaterials by combining X-ray absorption and emission spectroscopy and X-ray scattering analysis, and complementary DFT calculations. Here, he discovered the formation of an [Zn(oleylthioamide)4]2+ complex by dissolution of Zn(Ac)2 and elemental sulfur in oleylamine, already at room temperature, and mapped the transition of HOMO/LUMO gap to a band structure during the synthesis. The results were published in the Journal of the American Chemical Society (JACS)1 and highlighted in a research spotlight on the ESRF webpage. (https://www.esrf.fr/sites/www/home/news/spotlight/content-news/spotlight/x-ray-spectroscopy-reveals-the-electronic-structure-of-wide-bandgap-semiconductors.html)

He also worked on investigating the synthesis of ZnS nanoparticles at the water-toluene interface, using a nano-focused beam for spatially resolved X-ray absorption spectroscopy, with complementary analysis using X-ray total scattering methods. Here, he monitored the diffusion of Zn2+ species through the water-toluene interface and revealed the formation of amorphous ZnS nuclei prior to the crystallization of ZnS nanoparticles.2

During his PhD studies, he taught students in exercise groups in solid-state physics. He won the department’s teaching prize for the best supervision of an exercise group in the Summer Semester 2021. Congratulations!

In 2025, he successfully defended his PhD thesis and joined the lab of Tobias Beck as a postdoc. We wish you all the best for your future!

Selection of representative publications:

(1) Klemeyer, L.; Gröne, T. L. R.; Zito, C. d. A.; Vasylieva, O.; Gumus Akcaalan, M.; Harouna-Mayer, S. Y.; Caddeo, F.; Steenbock, T.; Hussak, S.-A.; Kesavan, J. K.; et al. Utilizing High X-ray Energy Photon-In Photon-Out Spectroscopies and X-ray Scattering to Experimentally Assess the Emergence of Electronic and Atomic Structure of ZnS Nanorods. Journal of the American Chemical Society 2024, 146 (49), 33475-33484. DOI: 10.1021/jacs.4c10257.

(2) Klemeyer, L.; Caddeo, F.; Gröne, T. L.; Harouna-Mayer, S. Y.; Jessen, B.; Zito, C. A.; Kesavan, J. K.; Dippel, A.-C.; Saldaña, F. I.; Mathon, O. Spatially Resolved In Situ HERFD-XANES studies of ZnS Nanoparticle Synthesis at the Water-Toluene Interface. 2025.