Charge carrier dynamics and coupling to the crystal lattice in Borophane

• Applicant: Professor Dr. Uwe Bovensiepen
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 572793540

Future technology will profit from novel materials with unprecedented properties. Borophane (HB) is one hot candidate since this material combines lightweight with abundantly available atoms, carries large electric current than, e.g., 100 times higher than graphene, and can store hydrogen. However, insights into its charge carrier dynamics and e-ph coupling which are essential for device development is widely lacking. Here we combine internationally leading expertise in Borophane synthesis and characterization with time-resolved spectroscopy and diffraction techniques. We propose to measure the charge carrier dynamics and coupling to phonons upon optical excitation in HB (honeycomb) in comparison to HB (5,7-membered) using soft x-ray spectroscopy at the B K-absorption edge and ultrafast electron diffraction. These pump-probe experiments will compare the dynamics for inter- and intraband optical pumping in order to associate elementary relaxation processes of the charge and lattice degrees of freedom with specific optical excitations. The resulting characteristic electronic and phononic relaxation times will serve as input for the development of large scale boron-based heterostructure systems and optoelectronic devices which we plan to demonstrate within this project as well.

• DFG Programme: Research Grants
• International Connection: Japan
• Partner Organisation: Japan Society for the Promotion of Science (JSPS)
• Cooperation Partner: Professor Dr. Iwao Matsuda