Symmetry breaking in 2D materials for optimizing second-harmonic generation
Journal
Journal of Physics D: Applied Physics
Journal Volume
57
Journal Issue
33
Start Page
333002
ISSN
00223727
13616463
Date Issued
2024
Author(s)
Abstract
Second-harmonic generation (SHG) is the generation of 2ω (or half wavelength) light from incident light with frequency ω as a nonlinear optical response of the material. Three-dimensional (3D) SHG materials are widely investigated for developing laser technology to obtain shorter wavelengths in photolithography fabrication of semiconductor devices and the medical sciences, such as for imaging techniques that do not use fluorescent materials. However, to obtain the optimized SHG intensity, the 3D material is required to have no spatial-inversion symmetry (or non-centrosymmetry) and special crystal structure (or so-called phase-matched condition). Recently, engineering symmetry breaking of thin two-dimensional (2D) materials whose 3D structure has the inversion symmetry can offer a breakthrough to enhance the SHG intensity without requiring the phase-matched condition. Over the past decade, many 2D SHG materials have been synthesized to have broken inversion symmetry by stacking heterostructures, twisted moire structures, dislocated nanoplates, spiral nanosheets, antiferromagnetic order, and strain. In this review, we focus on the recent progress in breaking inversion and rotational symmetries in out-of-plane and/or in-plane directions. The theoretical calculations and experimental setup are briefly introduced for the non-linear optical response of the 2D materials. We also present our perspectives on how these can optimize the SHG of the 2D materials.
Subjects
2d Materials
First-principles Calculations
Second-harmonic Generation
Stacking Order
Symmetry Breaking
Crystal Symmetry
Harmonic Analysis
Incident Light
Medical Imaging
Nonlinear Optics
Phase Matching
Semiconductor Lasers
2d Material
Condition
First Principle Calculations
Half Wavelength
Inversion Symmetry
Laser Technologies
Nonlinear Optical Response
Stacking Order
Symmetry Breakings
Harmonic Generation
Publisher
Institute of Physics
Type
review article