Dresden 2026 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 26: Poster II

HL 26.55: Poster

Wednesday, March 11, 2026, 09:30–11:30, P1

Ultrafast dynamics of exciton–exciton interaction in monolayer MoS₂ investigated by high-order pump–probe micro-spectroscopy — •Ruidan Zhu, Patrick Grenzer, Simon Büttner, Matthias Hensen, Tobias Hertel, and Tobias Brixner — Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany

Exciton–exciton interaction (EEI), as a many-body effect, sets a fundamental limit to optimizing the photoluminescence efficiency of light-emitting devices based on 2D materials under high exciton densities [1]. A detailed understanding of the underlying EEI mechanisms provides crucial insight for the optimization of the device performance. However, EEI dynamics are challenging to probe directly as their signatures are mixed with the dominant single-exciton background in conventional ultrafast measurements. Here, we apply our recently developed high-order pump–probe spectroscopy [2] in a cryo-microscope to study exciton interaction in freestanding and supported MoS₂ monolayers. We aim to separate different EEI-related processes (fifth and higher orders of the system’s nonlinear response) from the single-exciton dynamics (third order) and further investigate how the dielectric environment influences EEI dynamics. We present our current progress toward isolating EEI dynamics.

[1] Y. Yu et al., Phys. Rev. B 2016, 93, 201111.

[2] P. Malý et al., Nature 2023, 616, 280.

Keywords: Pump–probe micro-spectroscopy; Exciton–exciton interaction; Monolayer MoS$_2$; Higher-order signals; Substrate