In the last decade, molecular materials have emerged as a highly tunable class of materials with the potential to complement inorganic semiconductors for future electronic and light-harvesting applications. However, the implementation of molecular-based devices is still severely limited by our poor understanding of the transport and optical properties of these materials. To gain more insight into these material properties, static and time-resolved momentum-resolved photoemission has been established as a powerful tool. It allows us to study the band structure of molecular films and reveal the degree of localization of molecular valence orbitals through their characteristic emission pattern in momentum space. For example, this innovative approach gives us access to the momentum-space signatures of optically excited excitons, providing deep insights into their transient spatial distribution in molecular thin films. 

报告人简介：

Martin Aeschlimann is a professor of the physics department at the University of Kaiserslautern.  He received a Ph.D. from the ETH Zürich in 1985, focusing on the Magnetism at Surfaces and Ultrafast Magnetization Reversal with Spin-Polarized Photoemission. He was a postdoctor and a research associate at the National Institute of Standards and Technology (NIST) at the University of Rochester and ETH Zürich, before he became a professor at the University of Duisburg-Essen in 1998. He is currently a professor of the physics department at the University of Kaiserslautern.

Prof. Aeschlimann has been devoted to the investigation of ultrafast phenomena in solids, thin films and nanoparticles. This includes the combination of short pulsed laser systems with surface science technology in order to develop novel methods for measuring ultrafast relaxation processes in real time with high temporal and spatial resolution. He has made significant contributions to the ultrafast dynamics of nanostructures and magnetism. He served as the chair for the Condensed Matter Physics section of the Germany Physical Society (DPG) in 2015-2018, and he is the chair of the transregional collaborative research center “Spin+X”.