Broadband Emission Origin in Metal Halide Perovskites: Are Self‐Trapped Excitons or Ions?

Advanced Materials, Год журнала: 2023, Номер 35(51)

Опубликована: Март 29, 2023

Abstract It has always been a goal to realize high efficiency and broadband emission in single‐component materials. The appearance of metal halide perovskites makes it possible. Their soft lattice characteristics significant electron–phonon coupling synergistically generate self‐trapped excitons (STEs), contributing with large Stokes shift. Meanwhile, their structural/compositional diversity provides suitable active sites coordination environments for doping ns 2 ions, allowing 3 P n ( =0,1,2) → 1 S 0 transitions toward emission. ions is phenomenologically similar that STE emission, hindering in‐depth understanding origin, leading failure meet the design requirements practical applications. In this scenario, herein, fundamentals development such two mechanisms are summarized establish clear comprehensive phenomenon, which may pave way an ideal customization broadband‐emission perovskites.

Язык: Английский

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Circular polarization-resolved ultraviolet photonic artificial synapse based on chiral perovskite

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Ноя. 7, 2023

Abstract Circularly polarized light (CPL) adds a unique dimension to optical information processing and communication. Integrating CPL sensitivity with learning memory in photonic artificial synapse (PAS) device holds significant value for advanced neuromorphic vision systems. However, the development of such systems has been impeded by scarcity suitable active optoelectronic materials. In this work, we employ helical chiral perovskite hybrid combined single-wall carbon nanotubes achieve circularly ultraviolet sensing imaging. The heterostructure demonstrates long-term charge storage as evidenced multiple-pulsed transient absorption measurements highly sensitive circular polarization-dependent photodetection, thereby enabling efficient CPL-resolved synaptic behaviors. Significantly, our PAS sensor arrays adeptly visualize, discriminate, memorize distinct images up 93% recognition accuracy spiking neural network simulations. These findings underscore pivotal role perovskites advancing technology polarization-enhanced

Язык: Английский

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Chiral Hybrid Germanium(II) Halide with Strong Nonlinear Chiroptical Properties

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(41)

Опубликована: Авг. 23, 2023

Due to the pronounced anisotropic response circularly polarized light, chiral hybrid organic-inorganic metal halides have been regarded as promising candidates for application in nonlinear chiroptics, especially second-harmonic generation circular dichroism (SHG-CD) effect. However, designing novel lead-free with large anisotropy factors and high laser-induced damage thresholds (LDT) of SHG-CD remains challenging. Herein, we develop first germanium halide, (R/S-NEA)3 Ge2 I7 ⋅H2 O (R/S-NGI), systematically investigated its linear chiroptical properties. S-NGI R-NGI exhibit (gSHG-CD ) 0.45 0.48, respectively, along a LDT 38.46 GW/cm2 ; these were highest values among reported halides. Moreover, effective second-order optical coefficient could reach up 0.86 pm/V, which was 2.9 times higher than that commercial Y-cut quartz. Our findings facilitate new avenue toward halides, their implementation applications.

Язык: Английский

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The first chiral cerium halide towards circularly-polarized luminescence in the UV region

Science China Chemistry, Год журнала: 2024, Номер 67(6), С. 1961 - 1968

Опубликована: Фев. 7, 2024

Язык: Английский

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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

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Free Halogen Substitution of Chiral Hybrid Metal Halides for Activating the Linear and Nonlinear Chiroptical Properties

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(49), С. 26833 - 26842

Опубликована: Дек. 1, 2023

Halogen substitution has been proven as an effective approach to the band gap engineering and optoelectronic modulation of organic–inorganic hybrid metal halide (OIHMH) materials. Various high-performance mixed OIHMH film materials have primarily obtained through coordinated halogens in their inorganic octahedra. Herein, we propose a new strategy free halogen outside octahedra for constructing single crystals with chiral structures, resulting boost linear nonlinear chiroptical properties. The from DMA4[InCl6]Cl (DMA = dimethylammonium) DMA4[InCl6]Br facile antisolvent vaporization method produces centimeter-scale high thermal stability along quantum yield photoluminescence, conspicuous circularly polarized luminescence, greatly enhanced second harmonic generation (SHG). In particular, crystal features intrinsic structure, exhibiting significant SHG circular dichroism (SHG-CD) response highest reported anisotropy factor (gSHG-CD) 1.56 among enhancements both properties are directly attributed octahedral distortion. by confine introduced within sites lattice, thereby ensuring compositions successful employment such may broaden horizon regulation structures

Язык: Английский

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Boosted Second Harmonic Generation of a Chiral Hybrid Lead Halide Resonant to Charge Transfer Exciton from Metal Halide Octahedra to Ligand

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(19)

Опубликована: Март 12, 2024

Abstract Chiral hybrid organic–inorganic metal halides (HOMHs) offer an ideal platform for the advancement of second‐order nonlinear optical (NLO) materials owing to their inherent noncentrosymmetric structures. The enhancement nonlinearity chiral HOMHs could be achieved by matching free exciton and/or self‐trapped energy levels with desired NLO frequencies. However, current scarcity resonance modes and low ratio hamper further improvements performance. Herein, we propose a new resonant channel charge transfer (CT) excited states from halide polyhedra organic ligand boost HOMHs. model lead (C 7 H 10 N)PbBr 3 N=1‐ethylpyridinium) exhibits drastically enhanced second harmonic generation in deep CT energy, intensity up 111.0 times that KDP 10.9 urea. effective coefficient has been determined as high ~40.2 pm V −1 , balanced large polarization laser damage threshold. This work highlights contribution ligands construction enhancing coefficients halides, thus provides guidelines designing advanced photonic applications.

Язык: Английский

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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

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1D Tin(II)‐Based Chiral Hybrid Perovskite Single Crystals with Extremely Distorted Inorganic Chains for Second Harmonic Generation

Advanced Optical Materials, Год журнала: 2024, Номер 12(17)

Опубликована: Фев. 17, 2024

Abstract The organic–inorganic hybrid metal halides with chiral structures have attracted great attentions in the field of optoelectronic functional materials, especially for nonlinear optics. To date, second harmonic generation (SHG) properties several classes different ions been reported. However, SHG‐active tin(II)‐based materials are rarely explored, hindering deep understandings relationship between their and SHG properties. Herein, Sn 2+ successfully introduced into perovskites, four new species perovskites ( R / S ‐α‐PEA)SnX 3 (X = Cl Br, PEA phenylethylammonium) obtained. as‐grown crystals P 2 1 space group, highly distorted [SnX 6 ] octahedral units forming 1D chain lattice, due to effect stereochemically active lone pair 5s electrons . Such an response ≈1.4× Y‐cut α‐quartz ‐α‐PEA)SnBr ≈0.9× ‐α‐PEA)SnCl at 1020 nm excitation, high polarization ratio signals as well wide bandgaps transparency windows meanwhile. This work opens up a platform discovering more novel superior optical future.

Язык: Английский

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Magneto‐chiral Nonlinear Optical Effect with Large Anisotropic Response in Two‐Dimensional Halide Perovskite

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(21)

Опубликована: Март 28, 2024

Abstract The chiral organic–inorganic halide perovskites (OIHPs) are vital candidates for superior nonlinear optical (NLO) effects associated with circularly polarized (CP) light. NLO in materials often couples magnetic dipole (MD) transition, as well the conventional electric (ED) transition. However, importance of MD transition process OIHPs has not yet been recognized. Here, circular probe analysis second harmonic generation dichroism (SHG‐CD) provides direct evidence that contribution leads to a large anisotropic response CP lights OIHPs, (R‐/S‐MBACl) 2 PbI 4 . thin films exhibit great sensitivity over wide wavelength range, and g‐value reaches up 1.57 at where is maximized. Furthermore, it also effective light generator, outputting CP‐SHG maximum g‐factor 1.76 upon stimulation linearly This study deepens understanding relation between chirality magneto‐optical effect, such an efficient discrimination signal highly applicable chirality‐based sensor communication devices.

Язык: Английский

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