Ultrafast Optomechanical Strain in Layered GeS

Luo, Duan; Zhang, Baiyu; Sie, Edbert J.; Nyby, Clara M.; Fan, Qingyuan; Shen, Xiaozhe; Reid, Alexander H.; Hoffmann, Matthias C.; Weathersby, Stephen; Wen, Jianguo; Qian, Xiaofeng; Wang, Xijie; Lindenberg, Aaron M.

doi:10.1021/acs.nanolett.2c05048

DOE OSTI · 1991154

Ultrafast Optomechanical Strain in Layered GeS

Luo, Duan·Zhang, Baiyu·Sie, Edbert J.·Nyby, Clara M.·Fan, Qingyuan·Shen, Xiaozhe·Reid, Alexander H.·Hoffmann, Matthias C.·Weathersby, Stephen·Wen, Jianguo·Qian, Xiaofeng·Wang, Xijie·Lindenberg, Aaron M.

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Abstract

Strong coupling between light and mechanical strain forms the foundation for next-generation optical micro- and nano-electromechanical systems. Such optomechanical responses in two-dimensional materials present novel types of functionalities arising from the weak van der Waals bond between atomic layers. In this paper, by using structure-sensitive megaelectronvolt ultrafast electron diffraction, we report the experimental observation of optically driven ultrafast in-plane strain in the layered group IV monochalcogenide germanium sulfide (GeS). Surprisingly, the photoinduced structural deformation exhibits strain amplitudes of order 0.1% with a 10 ps fast response time and a significant in-plane anisotropy between zigzag and armchair crystallographic directions. Rather than arising due to heating, experimental and theoretical investigations suggest deformation potentials caused by electronic density redistribution and converse piezoelectric effects generated by photoinduced electric fields are the dominant contributors to the observed dynamic anisotropic strains. Our observations define new avenues for ultrafast optomechanical control and strain engineering within functional devices.

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2D materials 77 NANOSCIENCE AND NANOTECHNOLOGY band structure deformation lattices optomechanical coupling photoexcitation photostrictive effect polarization strain engineering ultrafast electron diffraction

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Luo, Duan, Zhang, Baiyu, Sie, Edbert J., Nyby, Clara M., Fan, Qingyuan, Shen, Xiaozhe, Reid, Alexander H., Hoffmann, Matthias C., Weathersby, Stephen, Wen, Jianguo, Qian, Xiaofeng, Wang, Xijie, Lindenberg, Aaron M.. 2023-03-10. Ultrafast Optomechanical Strain in Layered GeS. https://doi.org/10.1021/acs.nanolett.2c05048

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