Regensburg 2025 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 17: 2D Semiconductors and van der Waals Heterostructures III

HL 17.12: Talk

Tuesday, March 18, 2025, 12:30–12:45, H15

Surface acoustic wave-controlled photocurrent in few-layer TMDCs — •Benjamin Mayer, Felix Ehring, Matthias Weiß, Hubert Krenner, Ursula Wurstbauer, and Emeline Nysten — Institute of Physics, University of Münster, Germany

Surface acoustic waves (SAWs) provide a versatile platform for integrating GHz-frequency control and sensing schemes at micron-scale wavelengths on a chip. Combining the SAWs dynamic electric field, high-resolution optical spectroscopy, and electrical transport allows a deep insight in the optical properties and carrier transport processes in nanoscale materials, paving the way for innovative acousto-optoelectronic devices [1].

Here, we study the SAW-driven acousto-electric current (AEC) and the underlying charge carrier dynamics in mechanically exfoliated transition metal dichalcogenide (TMDC) 2D materials. To this aim, few-layered TMDCs are placed on top of two gold electrodes integrated in hybrid lithium niobate-based SAW-devices with design frequencies of 150-250MHz. The power and directional dependence of the induced AEC offer an initial understanding of the contact barriers forming at the Au-TMDC interface. By locally photodoping our samples, we establish a qualitative model for the formed Schottky and tunneling barriers, enabling the investigation of their influence on the wavelength-dependent SAW-driven charge carrier dynamics [2].

[1] J. Phys. D:Appl. Phys. 52(35):353001 (2019)

[2] Adv. Mater. 2402799 (2024)

Keywords: surface acoustic waves; acousto-electric effect