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Excitons are realizations of a correlated many-body wavefunction, consisting of a Coulomb-bound electron-hole pair. They are the dominant excitations in organic and two-dimensional semiconductors. Thus, to exploit the full optoelectronic potential of these materials, a complete microscopic understanding of excitons is crucial. This ultimately relies on the access to the correlated exciton wavefunction, which has hardly been realized in experiments. In this presentation, I will introduce the concepts of time-resolved photoemission orbital tomography and how it can be used to directly probe correlated exciton wavefunctions. [mehr]

With the elucidation of the importance of local structure in heterogeneous catalysis and the development of single-molecule electronics, there has been a strong desire to measure electrochemical interfaces with high spatial resolution. The electrochemical scanning tunneling microscope (EC-STM) allows direct observation of these interfaces at the nanoscale by measuring tunneling current between a metal tip and the electrode surface in solution. This talk will focus on my work measuring the redox reaction of a single ferrocene molecule using EC-STM using tripod-shaped molecules [1]. I will alsoshare a new method for fabricating EC-STM tips, which addresses a long-standing technical challenge in the field [2]. Finally, I will touch on the development of electrochemical tip-enhanced Raman spectroscopy (EC-TERS), which opens new possibilities for nanoscale spectroscopy on electrochemical interface [3].[1] Y. Kobayashi et al., J. Phys. Chem. C, 127, 746 (2023).[2] Y. Kobayashi et al., J. Phys. Chem. C, 127, 13929 (2023).[3] Y. Yokota et al., J. Phys. Chem. C 123, 2953 (2019). [mehr]