Probing Noncentrosymmetric 2D Materials by Fourier Space Second Harmonic Imaging
arXiv:2409.02071 · doi:10.1021/acsphotonics.4c01724
Abstract
The controlled assembly of twisted 2D structures requires precise determination of the crystal orientation of their component layers. In the established procedure, the second-harmonic generation (SHG) intensity of a noncentrosymmetric layer is recorded while rotating the polarization of both the incident laser field and detected SHG, which can be time-consuming and tedious. Here, we demonstrate that the crystal orientation of transition metal dichalcogenides and hexagonal boron nitride can be directly determined by recording SHG images generated by tightly focused laser beams in Fourier space. Using an azimuthally polarized laser beam, the SHG image distinctly reflects the hexagonal structure of the crystal lattice, revealing its orientation quickly and accurately. This technique could significantly impact the field of twistronics, which studies the effects of the relative angle between the layers of a stacked 2D structure, as well as advances the nanofabrication of 2D materials.
22 (35) pages, 6 (12) figures (including Supplementary Information)
References in corpus (14)
- Electric Field Effect in Atomically Thin Carbon Films
- Excitons in atomically thin transition metal dichalcogenides
- Tightly bound excitons in monolayer WSe2
- Probing Excitonic Dark States in Single-layer Tungsten Disulfide
- Exciton physics and device application of two-dimensional transition metal dichalcogenide semiconductors
- Observation of Intense Second Harmonic Generation from MoS Atomic Crystals
- Second harmonic microscopy of monolayer MoS2
- Electrical Control of Second-Harmonic Generation in a WSe2 Monolayer Transistor
- Comparative analysis of imaging configurations and objectives for Fourier microscopy
- Programming moiré patterns in 2D materials by bending
- Ultra-clean assembly of van der Waals heterostructures
- Nonlinear dark-field imaging of 1D defects in monolayer dichalcogenides
- Second- and third-order optical susceptibilities in bidimensional semiconductors near excitons states
- Fourier plane optical microscopy and spectroscopy