Anisotropic Enhancement of Second-Harmonic Generation in Monolayer and Bilayer MoS2 by Integrating with TiO2 Nanowires

Dawei Li, Chengyiran Wei, Jingfeng Song, Xi Huang, Fei Wang, Kun Liu, Wei Xiong, Xia Hong, Bai Cui, Aixin Feng, Lan Jiang, Yongfeng Lu

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

The ability to design and enhance the nonlinear optical responses in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) is both of fundamental interest and highly desirable for developing TMDC-based nonlinear optical applications, such as nonlinear convertors and optical modulators. Here, we report for the first time a strong anisotropic enhancement of optical second-harmonic generation (SHG) in monolayer molybdenum disulfide (MoS2) by integrating with one-dimensional (1D) titanium dioxide nanowires (NWs). The SHG signal from the MoS2/NW hybrid structures is over 2 orders of magnitude stronger than that in the bare monolayer MoS2. Polarized SHG measurements revealed a giant anisotropy in SHG response of the MoS2/NW hybrid. The pattern of the anisotropic SHG depends highly on the stacking angle between the nanowire direction and the MoS2 crystal orientation, which is attributed to the 1D NW-induced directional strain fields in the layered MoS2. A similar effect has also been observed in bilayer MoS2/NW hybrid structure, further proving the proposed scenario. This work provides an effective approach to selectively and directionally designing the nonlinear optical response of layered TMDCs, paving the way for developing high-performance, anisotropic nonlinear photonic nanodevices.

Original languageEnglish (US)
Pages (from-to)4195-4204
Number of pages10
JournalNano Letters
Volume19
Issue number6
DOIs
StatePublished - Jun 12 2019

Keywords

  • 2 D/1D hybrid
  • Second-harmonic generation
  • anisotropic enhancement
  • strain field
  • transition metal dichalcogenides

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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    Li, D., Wei, C., Song, J., Huang, X., Wang, F., Liu, K., Xiong, W., Hong, X., Cui, B., Feng, A., Jiang, L., & Lu, Y. (2019). Anisotropic Enhancement of Second-Harmonic Generation in Monolayer and Bilayer MoS2 by Integrating with TiO2 Nanowires. Nano Letters, 19(6), 4195-4204. https://doi.org/10.1021/acs.nanolett.9b01933