Prof. Dr. Frank Stienkemeyer
Physikalisches Institut, Uni Freiburg
gives a talk on the subject:
Nanocluster Isolation: Advancing Spectroscopic Techniques for Photodynamics in Optoelectronics
Understanding the fundamental processes triggered by photon absorption in photovoltaic and optoelectronic materials requires experimental techniques that combine ultrahigh spectral resolution with ultrafast temporal sensitivity. While laser-based methods excel in either domain, many condensed-phase samples pose intrinsic limitations: thermal broadening, structural disorder, and complex, coupled
environments often obscure quantum-state–specific dynamics.
Superfluid helium nanodroplets and rare-gas clusters offer a powerful alternative.
Providing an ultracold, weakly perturbing matrix at temperatures down to the millikelvin regime, they enable the controlled assembly of molecular complexes and nanostructures ideally suited for disentangling elementary excitation and charge-transfer pathways.
Our approach combines fluorescence detection with photoionization and photoelectron spectroscopy, complemented by femtosecond pump–probe techniques for real-time tracking of light-induced dynamics. In particular, time-resolved photoelectron spectroscopy provides direct access to ultrafast relaxation cascades following electronic excitation. I will discuss recent results, the opportunities and limitations associated with different matrix environments, and how they shape the accessible
observables.
Finally, examples will be presented, demonstrating how coherent multidimensional spectroscopy can further enhance spectro‑temporal resolution and overcome the limitations of conventional methods, opening new avenues for resolving photodynamic processes.
Interested parties are cordially invited.
Prof. Dr. Szameit