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arXiv · 1701.02249

Photostrictive two-dimensional materials in the monochalcogenide family

Raad Haleoot·Charles Paillard·Mehrshad Mehboudi·Bin Xu·L. Bellaiche·Salvador Barraza-Lopez
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Abstract

Photostriction is predicted for SnS and SnSe monolayers, two-dimensional ferroelectrics with rectangular unit cells (the lattice vector $\mathbf{a}_1$ is larger than $\mathbf{a}_2$) and an intrinsic dipole moment parallel to $\mathbf{a}_1$. Photostriction in these two-dimensional materials is found to be induced by a screened electric polarization in the photoexcited electronic state (i.e., a converse piezoelectric effect) that leads to a compression of $a_1$ and a comparatively smaller increase of $a_2$ for a reduced unit cell area. The structural change documented here is ten times larger than that observed in BiFeO$_3$, making monochalcogenide monolayers an ultimate platform for this effect. This structural modification should be observable under experimentally feasible densities of photexcited carriers on samples that have been grown already, having a potential usefulness for light-induced, remote mechano-opto-electronic applications.

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Raad Haleoot, Charles Paillard, Mehrshad Mehboudi, Bin Xu, L. Bellaiche, Salvador Barraza-Lopez. 2017-01-09. Photostrictive two-dimensional materials in the monochalcogenide family. https://doi.org/10.1103/physrevlett.118.227401

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