Tailoring Dispersion Property and Anisotropy of Second-Harmonic Generation by Strain Engineering in Monolayer GeSe

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: 128(31), P. 13353 - 13361

Published: July 31, 2024

Strain engineering on the dispersion property and anisotropy of second-harmonic generation (SHG) is crucial for advancing understanding development nonlinear optical materials devices with tailored light-matter interactions. Herein, we theoretically demonstrate intricate relationship between strain modulation SHG in ferroic monolayer GeSe. The bandgap tends to expand upon application strain, be it uniaxial or biaxial nature. It important note that neither nor strains induce emergence novel nonzero second-order susceptibility elements; they do exert a significant influence pre-existing elements. This alteration has consequential effect process. Additionally, characteristic peak coefficient element d11 undergoes shift increase attributed variation interband transition contributions induced by strain. imposition whether biaxial, can markedly alter anisotropic properties response. These modifications are observed contingent factors such as wavelength, azimuthal angle, polarization incidence angle. findings provide valuable insights into design optimization 2D optoelectronic applications, highlighting potential powerful tool tailoring properties.

Language: Английский

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Atomically-precise synthesis and simultaneous integration of 2D transition metal dichalcogenides enabled by nano-confinement

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 7, 2024

Two-dimensional (2D) materials, such as graphene and transition metal dichalcogenides (TMDs), possess intriguing properties imparted by their unique atomic-scale structures, greatly enriched various van der Waals (vdW) homo-/heterostructures. Therefore, the precise synthesis of 2D TMDs vdW integration with clean interfaces are highly desired, while still challenging. Here, we present a nano-confined chemical vapor deposition approach which enables atomically-precise simultaneous graphene. Within nano-confinement, (e.g., NbSe₂) that tend to form thick crystals precisely monolayered owing an unusual growth kinetics underneath A sub-monolayer architecture, Janus S-Mo-Se polar chalcogen arrangement, is further achieved nano-confinement effects. The TMD monolayer guarantees ultraclean interface gives rise emergent properties. Examples include conduction enhancement in graphene/NbSe₂ heterostructure photomemory effect graphene/Janus MoSSe heterostructure. Our results provide promising platform realize monolayers.

Language: Английский

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Novel exciton behavior in low-dimensional polarized MoSSe/GaN heterostructures: A first-principles study

Physical Review Materials, Journal Year: 2024, Volume and Issue: 8(12)

Published: Dec. 16, 2024

Excitonic effects are important in many low-dimensional materials due to a reduced dielectric screening which generally enhances exciton binding strengths. For the class of two-dimensional layered materials, we examine monolayers GaN, $\mathrm{Mo}{\mathrm{S}}_{2}$, and MoSSe as well heterojunctions composed two layers: GaN MoSSe. Employing many-body perturbation theory for quasiparticle band structure (GW theory) solving Bethe-Salpeter equation excitons, systematically study optical properties these systems. We also include spin-orbit coupling our analysis elucidate its influence on frontier orbitals. It is found that lowest four excitons appear at about 1.65 eV have energy 0.67 eV. These either red-shifted or blue-shifted when forming heterojunctions, depending polarization junction. properties, strength spatial localization (interlayer versus intralayer) correlated with system's strength, opening way tune such systems by varying strength.

Language: Английский

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Giant Ultrabroadband Bulk Photovoltaic Effect Engendered by Two‐Photon Absorption in α‐In₂Se₃ for Chiral Terahertz Wave Generation

Advanced Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 15, 2024

Bulk photovoltaic effect (BPVE) can break the Shockley-Queisser limit by leveraging inherent asymmetry of crystal lattice without a junction. However, this is mainly confined to UV-vis spectrum due wide-bandgap nature traditional ferroelectric materials, thereby limiting exploration infrared light-driven efficient BPVE. Herein, giant two-photon absorption (TPA) driven BPVE uncovered from visible in α-In

Language: Английский

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Inversion symmetry-broken tetralayer graphene probed by second harmonic generation

arXiv (Cornell University), Journal Year: 2023, Volume and Issue: unknown

Published: Jan. 1, 2023

Symmetry breaking governs most fascinating phenomena in crystals, such as ferroelectricity, nonlinear optics, piezoelectricity, ferromagnetism, and superconductivity. In two-dimensional materials, a wide variety of tuning knobs presents extraordinary opportunities for engineering symmetry breaking, leading to the emergence manipulation novel physical properties. Recently, tetralayer graphene with ABCB stacking order is predicted possess atypical elemental ferroelectricity arising from induced by its specific configuration. Experimentally unveiling stacking-order dependent crucial understand intricate properties emergent allotropes. Here, we observe pronounced optical second harmonic generation (SHG) ABCB-stacked graphene, but absent both ABAB- ABCA-stacked Our results provide direct evidence graphene. The remarkable contrast SHG spectra allows straightforward identification domains other two kinds facilitates characterization their crystalline orientation. employed technique serves convenient tool exploring intriguing physics optics where spontaneous polarization intrinsic gapped flat bands coexist. establish unique platform studying rare non-centrosymmetric structures.

Language: Английский

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