Enhanced second-harmonic generation from WS 2 /ReSe 2 heterostructure

Shaikh, Kanchan [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000335640000); Yoo, Taejun [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0009000742154787); Zhu, Zeyuan [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0009000204316347); Li, Qiuyang [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000281923960); Johnson, Amalya C. [Stanford Univ., CA (United States)] (ORCID:000000029604984X); Deng, Hui [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000306293230); Liu, Fang [Stanford Univ., CA (United States)] (ORCID:0000000214678328); Kobayashi, Yuki [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000243911328)

doi:10.1063/5.0313933

DOE OSTI · 3363458

Enhanced second-harmonic generation from WS 2 /ReSe 2 heterostructure

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Abstract

Van der Waals stacking presents new opportunities for nonlinear optics with its remarkable tunability and scalability. However, the fundamental role of interlayer interactions in modifying the overall nonlinear optical susceptibilities remains elusive. In this work, we report anisotropic enhancement of second-harmonic generation (SHG) from a WS 2 /ReSe 2 heterobilayer, where the individual composite layers possess distinctive crystal phases. We investigate polarization-resolved response and twist-angle dependence in SHG and reveal that band alignment alone is insufficient to explain the observed anisotropy in the modified SHG response. Spectral shifts in excitonic features highlight band renormalization, supporting the role of hybridization between the two layers. Furthermore, SHG enhancement is highly anisotropic and can even be suppressed in some orientations, suggesting possible intensity-borrowing mechanisms within the heterostructure. Our work demonstrates the ability to tune both the intensity and polarization dependence of nonlinear optical responses with van der Waals stacking of distinctive crystal phases.

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2D materials 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY Nonlinear optical properties

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Shaikh, Kanchan [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000335640000), Yoo, Taejun [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0009000742154787), Zhu, Zeyuan [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0009000204316347), Li, Qiuyang [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000281923960), Johnson, Amalya C. [Stanford Univ., CA (United States)] (ORCID:000000029604984X), Deng, Hui [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000306293230), Liu, Fang [Stanford Univ., CA (United States)] (ORCID:0000000214678328), Kobayashi, Yuki [Univ. of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000243911328). 2026-03-09. Enhanced second-harmonic generation from WS 2 /ReSe 2 heterostructure. https://doi.org/10.1063/5.0313933

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