Second Harmonic Generation Control in 2D Layered Materials: Status and Outlook

Advanced Functional Materials, Год журнала: 2024, Номер 34(16)

Опубликована: Янв. 4, 2024

Abstract Second harmonic generation (SHG) as an essential nonlinear optical effect, has gradually shifted its research trend toward the integration and miniaturization of photonic optoelectronic on‐chip devices in recent years. 2D layered materials (2DLMs) open up a new paradigm optics due to their large second‐order susceptibility, atomically thin structure, perfect phase‐matching. However, 2DLMs are facing bottleneck weak SHG conversion efficiency limit caused by short light–matter interaction lengths at nanoscale. Moreover, advances integrated based on rely continuing development novel strategies with tunable efficient responses. Here, this review provides comprehensive overview progress exploring highly responses 2DLMs. Various modulation enhancement for response extensively studied systematically discussed, which can be classified into two categories: symmetry breaking light‐matter enhancement. remaining challenges outlooks further extending realizing practical applications characteristics discussed.

Язык: Английский

---

Anisotropic Strain-Tailoring Nonlinear Optical Response in van der Waals NbOI₂

Nano Letters, Год журнала: 2024, Номер 24(11), С. 3413 - 3420

Опубликована: Март 8, 2024

Two-dimensional (2D) NbOI2 demonstrates significant second-harmonic generation (SHG) with a high conversion efficiency. To unlock its full potential in practical applications, it is desirable to modulate the SHG behavior while utilizing intrinsic lattice anisotropy. Here, we demonstrate direction-specific modulation of response by applying anisotropic strain respect orientations, where more than 2-fold enhancement intensity achieved under along polar axis. The strain-driven evolution attributed strengthened built-in piezoelectric field (polar axis) and enlarged Peierls distortions (nonpolar axis). Moreover, provide quantifications correlation between terms susceptibility tensor. Our results effective coupling orientation-specific through order 2D nonlinear optical crystals, opening new paradigm toward development functional devices.

Язык: Английский

---

Highly Birefringent d⁰ Transition Metal Fluoroantimonite in the Mid Infrared Band: Order–Disorder Regulation by Cationic Size

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(44), С. 24416 - 24424

Опубликована: Окт. 26, 2023

An unusual O/F ordered d0 transition metal fluoroantimonite, namely, K2SbMoO2F7, has been created by the cationic size effect of alkali metals. It features largest birefringence 0.220@550 nm among inorganic antimonites with a halogen element, which is an order magnitude larger than disordered A2SbMoO2F7 (A = Rb, Cs). These three new compounds exhibit two different structures, although all structures were made [SbMoO2F7]2- chains formed SbF5 square pyramids and MoO2F4 octahedrons. A transparent single crystal K2SbMoO2F7 dimensions 7.0 × 5.0 1.0 mm3 successfully grown aqueous solution volatilization method. The UV-vis-MIR transmission spectrum showed that can display excellent transmittance in range 0.5-5.0 μm 6.0-9.8 μm, indicating its application potential as birefringent material mid infrared band. This work offers fresh approach to design synthesis materials.

Язык: Английский

---

Pressure-Modulated Anomalous Organic–Inorganic Interactions Enhance Structural Distortion and Second-Harmonic Generation in MHyPbBr₃ Perovskite

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(43), С. 23842 - 23848

Опубликована: Окт. 20, 2023

Organic-inorganic halide perovskites possess unique electronic configurations and high structural tunability, rendering them promising for photovoltaic optoelectronic applications. Despite significant progress in optimizing the characteristics of organic cations inorganic framework, role organic-inorganic interactions determining optical properties has long been underappreciated remains unclear. Here, by employing pressure tuning, we realize continuous regulation a lead perovskite, MHyPbBr3 (MHy+ = methylhydrazinium, CH3NH2NH2+). Compression enhances strengthening Pb-N coordinate bonding N-H···Br hydrogen bonding, which results higher distortion framework. Consequently, second-harmonic-generation (SHG) intensity experiences an 18-fold increase at 1.5 GPa, order-disorder phase transition temperature increases from 408 K under ambient to 454 industrially achievable level 0.5 GPa. Further compression triggers sudden non-centrosymmetric centrosymmetric transition, accompanied anomalous bandgap 0.44 eV, stands as largest boost all known perovskites. Our findings shed light on intricate correlations among interactions, octahedral distortion, SHG and, more broadly, provide valuable insights into design property optimization through cation engineering

Язык: Английский

---

Breaking Through the Trade‐Off Between Wide Band Gap and Large SHG Coefficient in Mercury‐Based Chalcogenides for IR Nonlinear Optical Application

Small, Год журнала: 2023, Номер 20(6)

Опубликована: Окт. 2, 2023

Abstract It is substantially challenging for non‐centrosymmetric (NCS) Hg‐based chalcogenides infrared nonlinear optical (IR‐NLO) applications to realize wide band gap ( E g > 3.0 eV) and sufficient phase‐matching (PM) second‐harmonic‐generation intensity d eff 1.0 × benchmark AgGaS 2 ) simultaneously due the inherent incompatibility. To address this issue, work presents a diagonal synergetic substitution strategy creating two new NCS quaternary chalcogenides, AEHgGeS 4 (AE = Sr Ba), based on centrosymmetric (CS) AEIn S . The derived displays excellent NLO properties such as (≈3.04–3.07 eV), large PM (≈2.2–3.0 ), ultra‐high laser‐induced damage threshold (≈14.8–15 suitable Δ n (≈0.19–0.24@2050 nm), making them highly promising candidates IR‐NLO applications. Importantly, second‐order are primarily attributed synergistic combination of tetrahedral [HgS ] [GeS functional primitives, supported by detailed theoretical calculations. This study reports first materials with well‐balanced comprehensive (i.e., eV puts forward design avenue construction more efficient candidates.

Язык: Английский

---

Phase and Composition Engineering of Self-Intercalated 2D Metallic Tantalum Sulfide for Second-Harmonic Generation

ACS Nano, Год журнала: 2024, Номер 18(8), С. 6256 - 6265

Опубликована: Фев. 14, 2024

Self-intercalation in two-dimensional (2D) materials is significant, as it offers a versatile approach to modify material properties, enabling the creation of interesting functional materials, which essential advancing applications across various fields. Here, we define ic-2D covalently bonded compounds that result from self-intercalation metal into layered 2D compounds. However, precisely growing with controllable phases and concentrations fully exploit family remains great challenge. Herein, demonstrated controlled synthesis self-intercalated H-phase T-phase Ta1+xS2 via temperature-driven chemical vapor deposition (CVD) viable intercalation concentration spanning 10% 58%. Atomic-resolution scanning transmission electron microscopy-annular dark field imaging Ta atoms occupy octahedral vacancies located at van der Waals gap. The nonperiodic break centrosymmetry structure Fermi surface properties intrinsic TaS2. Therefore, consistently exhibit spontaneous nonlinear optical (NLO) effect regardless sample thickness concentrations. Our results propose an activate NLO response centrosymmetric achieving modulation wide range optoelectronic family.

Язык: Английский

---

Near Ultraviolet‐Excitable Cyan‐Emissive Hybrid Copper(I) Halides Nonlinear Optical Crystals with Near‐Unity Photoluminescence Quantum Yield and High‐Efficiency X‐ray Scintillation

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Авг. 23, 2024

Designing and synthesizing multifunctional hybrid copper halides with near ultraviolet (NUV) light-excited high-energy emission (<500 nm) remains challenging. Here, a pair of broadband-excited emitting isomers, namely, α-/β-(MePh

Язык: Английский

---

Quantifying Structural Polarization by Continuous Regulation of Lone-Pair Electron Expression in Molecular Crystals

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(32), С. 22469 - 22475

Опубликована: Авг. 1, 2024

Rational design of structural polarization is vital for modern technologies, as it allows the physical properties functional materials to be tailored. An effective approach governing involves utilization stereochemical lone-pair electrons (LPEs). However, despite recognized significance LPEs in controlling polarization, there remains a lack understanding regarding quantitative relationship between their expression and extent polarization. Here, by using pressure continuously tune LPE expression, we achieve precise control quantification which brings enhanced second harmonic generation (SHG) molecular crystal SbI

Язык: Английский

---

Pressure treatment enables white-light emission in Zn-IPA MOF via asymmetrical metal-ligand chelate coordination

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Янв. 15, 2025

Metal-organic frameworks that feature hybrid fluorescence and phosphorescence offer unique advantages in white-emitting communities based on their multiple emission centers high exciton utilization. However, it poses a substantial challenge to realize superior white-light single-component metal-organic without encapsulating varying chromophores or integrating phosphor subunits. Here, we achieve high-performance with photoluminescence quantum yield of 81.3% via boosting triplet excitons distribution through pressure treatment Zn-IPA frameworks. A novel metal-ligand asymmetrical chelate coordination is successfully integrated into the after high-pressure over ~20.0 GPa. This modification unexpectedly endows targeted sample new emergent electronic state narrow singlet-triplet energy gap, which effectively accelerates spin-flipping process for boosted population. Time delay phosphor-converted light-emitting diodes are fabricated long time up ~7 s switching off, providing significant advancements time-delay lighting applications. Pressure-treatment can alter optical properties Here authors induce amorphization remains decompression enables efficient narrowing gap.

Язык: Английский

---

In-Plane Bulk Photovoltaic Effect in a MoSe₂/NbOI₂ Heterojunction for Efficient Polarization-Sensitive Self-Powered Photodetection

Nano Letters, Год журнала: 2025, Номер unknown

Опубликована: Янв. 15, 2025

Two-dimensional ferroelectric materials can generate a bulk photovoltaic effect, making them highly promising for self-powered photodetectors. However, their practical application is limited by weak photoresponse due to transition strength and wide band gap. In this study, we construct van der Waals heterojunction using NbOI2, which has significant in-plane polarization, with absorbing MoSe2 layer. We observe ultrafast hole transfer from NbOI2 within 0.4 ps electron in the opposite direction 3.8 ps, facilitating efficient charge dissociation extraction. Applying direct current electric field poling modulates domains enhancing effect. This results one of highest responsivities photodetectors (101.3 mA/W) at 0 V bias alongside excellent polarization sensitivity (∼7.58). work advances understanding self-powering mechanisms via effect proposes new strategies future devices.

Язык: Английский

---