CHEMISTRY OF MATERIALS
·
2024
·
IF 7.2
Yan Guo,Wen-Fa Chen,Ming-Xin Li,Fan Wu,Qiupei Qin,Bin-Wen Liu,Xiao-Ming Jiang,Guo-Cong Guo
To address the challenge of nonphase matching in many infrared (IR) nonlinear optical (NLO) materials, despite having substantial NLO coefficients, we present a new strategy for realizing phase matching (PM) in IR NLO materials by manipulating the fractal dimension (FD) of covalent motifs. As a representative demonstration, we select a salt-inclusion chalcogenide system and validate its efficacy. Consequently, we successfully synthesized two new chalcogenides, denoted as K2[K4Cl][Ga5Sn7S24] (1) and [Na4I][Ga9S15] (2). The latter exhibits PM, while the former does not, primarily attributed to their markedly different FD values of the electron localization function map, resulting in distinct optical anisotropy. Compounds 1 and 2 demonstrate enhanced IR NLO efficiency, measuring 0.25 and 0.70 times that of AgGaS2 at 1910 nm, respectively. Notably, compound 2 features a wide band gap of 3.10 eV and a substantial-high laser-induced damage threshold (LIDT) of 93.15 MW cm–2@1064 nm (9.6 × AgGaS2). This work illuminates the exploration of new PM IR NLO materials derived from nonphase matching counterparts.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2017
·Vol. 4
·期 11
·1900-1908
·
IF 4.036
Hafiz Muhammad Asif,Ningning Qu,Yunshan Zhou,Lijuan Zhang,Farooq Khurrum Shehzad,Zonghai Shi,Yi Long,Sadaf Ul Hassan
Composite films with alternating layers (PAH/PSS)3(AB/POM)n (PAH = polyallylamine hydrochloride, PSS = polystyrene sulfonate) derived from Alcian Blue-tetrakis(methyl-pyridinium) chloride (abbreviated as AB) and Keggin type polyoxometalates (POM = H4SiW12O40, H3PW12O40, H3PMo12O40, H5PMo10V2O40) have been fabricated and characterized. Under laser irradiation at 532 nm with a pulse duration of 6–7 ns, a repetition rate of 10 Hz and the intensity of the light at focus E0 being 10 μJ, the composite films exhibit self-defocusing behavior and saturated absorption effects, and the nonlinear optical absorption coefficient β (m W−1) and refractive index n2 (m2 W−1) of the films are 4–5 times larger than those of pure AB solution in view of their magnitude. Interestingly, it is found that third-order NLO susceptibilities χ(3) of films are in the order of χ(3)(AB/PSS) < χ(3)(AB/SiW12) < χ(3)(AB/PW12) < χ(3)(AB/PMo12) < χ(3)(AB/PMo10V2), which is reversed to the order of ELUMO(SiW12) > ELUMO(PW12) > ELUMO(PMo12) > ELUMO(PMo10V2), affirming that the incorporation of different Keggin type POMs of a lower LUMO energy level with phthalocyanine molecules into multilayers could tune the NLO responses of phthalocyanine films. It is concluded that the lower LUMO level of POM than that of the phthalocyanine can stimulate the easier transformation of excited electrons from AB to the POM within the donor–acceptor system (phthalocyanine molecules acted as an electron donor while POMs as an electron acceptor in the composite films) when flashed with the laser, which is thought to be accountable for the profound third-order optical nonlinearity of the composite films.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 8
·期 4
·1380-1390
·
IF 6.641
Hui Zhang,Yanxin Tian,Shuhui Bo,Linghan Xiao,Yuhui Ao,Ji Zhang,Ming Li
In order to improve the first-order hyperpolarizability (β) of the chromophore and transform it into a high macroscopic electro-optic activity, a series of novel second-order nonlinear optical chromophores with different push–pull electron groups introduced on the thiophene π-conjugate bridge for tuning the shape and dipole moment (μ) of chromophores were designed and synthesized. These chromophores are based on the same thiophene π-conjugated bridge, where the donor (N,N-diethylaniline) and acceptor (2-(3-cyano-4,5,5-trimethylfuran-2(5H)-ylidene)malononitrile or malononitrile) are linked to positions 2 and 3 of thiophene, respectively, affording a boomerang-like shape instead of a rod-like shape. Besides, an electron-poor group, Br (bromine atom), or an electron-rich group, DEA (N,N-diethylaniline), as an auxiliary acceptor or donor are linked to position 5 of thiophene. In addition, all chromophores showed good thermal stability as per the results from the DSC and TGA analysis. Through UV-vis analysis and DFT calculation, it has been concluded that chromophores with additional electron-rich groups as auxiliary donors display better intermolecular charge-transfer (ICT) absorption and lower HOMO–LUMO energy gaps (ΔE). Furthermore, the boomerang-like chromophore with the same push–pull structure shows a smaller dipole moment (μ) and β value than the traditional FTC. The poling results of guest–host EO polymers FTC/APC, FTC-H/APC, FTC-Br/APC and FTC-DEA/APC with the same number density afford r33 values of 17 pm V−1, 11 pm V−1, 10 pm V−1 and 25 pm V−1, respectively. Although the β value of FTC-DEA is smaller than that of FTC, the r33 value of FTC-DEA (25 pm V−1) is 47% greater than that of FTC (17 pm V−1) under the same number density. Hence, the above-mentioned results indicated that regulating the conjugate position of chromophores can efficiently decrease the dipole moment of the chromophores, weakening the dipole–dipole interactions and thereby enhancing the macroscopic electro-optical activity of poled polymers. These results indicate the potential application of these novel chromophores in electro-optical devices.
研究领域:
材料科学
·
有机化学
✓ 已验证
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2024
·
IF 7.2
Yan Guo,Bin-Wen Liu,Chao-Hong Xie,Wen-Fa Chen,Ming-Xin Li,Xiao-Ming Jiang,Guo-Cong Guo
Rare-earth infrared nonlinear optical (IR NLO) compounds have garnered significant attention due to their abundant electronic structures. However, their NLO efficiency has been relatively modest, attributed to the localization of valence electron shells in rare-earth metals. Traditional design strategies for IR NLO materials have predominantly focused on MQ4 (M = metal, Q = S or Se) tetrahedra, with limited exploration of MQ6 octahedra. We introduce a novel approach to enhance NLO effects by incorporating distorted mixed anionic octahedral M(S/X)6 groups. To illustrate this strategy, we undertake structure modification and optimization of IR NLO performance using the Y–Ga–Ge–S system as an example. The synthesis of a new rare-earth chalcogenide, Y6Ga2GeS14 (1), serves as a foundation. Further halogen atom substitution yields Y6Ga4.2S13.6Cl3.4 (2), Y6Ga2.83Ge2S16.75Cl (3), and Y6Ga2.83Ge2S16.5Br1.5 (4). All compounds demonstrate remarkable NLO performance, including moderate NLO coefficients (0.17–0.70 × AgGaS2), large laser-induced damage thresholds (LIDTs) (3.78–6.19 × AgGaS2), and a broader transmission range (0.5–14.9 μm). The incremental enhancement of NLO efficiency in compounds 1–4 can be attributed to symmetry breaking induced by halogen atom substitution and increased distortion of the octahedral M(S/X)6 motifs in their structures, validating the effectiveness of our strategy. Notably, this strategy concurrently increases the band gap and LIDT, overcoming the NLO–LIDT incompatibility, being strikingly different from other reported approaches. This work provides new insights into optimizing the NLO performance of rare-earth IR NLO compounds through the modulation of octahedral motifs.
研究领域:
材料科学
·
光学
·
化学
·
物理学
✓ 已验证
DOI
高影响因子
Chemical Science
·
2023
·Vol. 14
·期 46
·13568-13573
·
IF 8.4
Zhi-Xin Qiu,Zhe-Xiong Zheng,Xiao-Ming Jiang,Bin-Wen Liu,Guo-Cong Guo
Crystallographically, noncentrosymmetricity (NCS) is an essential precondition and foundation of achieving nonlinear optical (NLO), pyroelectric, ferroelectric, and piezoelectric materials. Herein, structurally, octahedral [SmCl6]3− is substituted by the acentric tetrahedral polyanion [CdBr4]2−, which is employed as a templating agent to induce centrosymmetric (CS)-to-NCS transformation based on the new CS supramolecule [Cd5P2][SmCl6]Cl (1), thereby providing the NCS supramolecule [Cd4P2][CdBr4] (2). Meanwhile, this replacement further results in the host 2D ∞2[Cd5P2]4+ layers converting to yield the twisted 3D ∞3[Cd4P2]2+ framework, which promotes the growth of bulk crystals. Additionally, phase 2 possesses well-balanced NLO properties, enabling considerable second-harmonic generation (SHG) responses (0.8–2.7 × AgGaS2) in broadband spectra, the thermal expansion anisotropy (2.30) together with suitable band gap (2.37 eV) primarily leading to the favorable laser-induced damage threshold (3.33 × AgGaS2), broad transparent window, and sufficient calculated birefringence (0.0433) for phase-matching ability. Furthermore, the first polyanion substitution of the supramolecule plays the role of templating agent to realize the CS-to-NCS transformation, which offers an effective method to rationally design promising NCS-based functional materials.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）