Showing papers by "Jiang-Gao Mao published in 2021"
TL;DR: In this article, the authors presented four facile and rational molecular design strategies: (1) traditional BO33-based crystals feature short absorption edges but usually suffer from relatively weak SHG performance (<5 × KDP).
Abstract: ConspectusSecond-harmonic-generation (SHG) causes the frequency doubling of light, which is very useful for generating high-energy lasers with specific wavelengths. Noncentrosymmetry (NCS) is the first requirement for an SHG process because the SHG coefficient is zero (χ2 = 0) in all centrosymmetric structures. At this stage, developing novel NCS crystals is a crucial scientific topic. Assembling polar units in an addictive fashion can facilely form NCS crystals with outstanding SHG performance. In this way, our group has obtained many different NCS crystals with extremely large SHG intensities (>5 × KDP or 1 × KTP). In this Account, we first provide a brief review of the development of SHG materials and concisely highlight the features of the excellent SHG materials. Then, we present four facile and rational molecular design strategies: (1) Traditional BO33--based crystals feature short absorption edges but usually suffer from relatively weak SHG performance (<5 × KDP). The combination of two types of pure π-conjugated anions (BO33- and NO3-) in a parallel fashion in the same compound has afforded a metal borate nitrate with a strong SHG effect. (2) To overcome the problems of the weak SHG effect and small birefringence in the less anisotropic QO4-based compounds, highly polarizable cations such as Hg2+ and Bi3+ are introduced into these systems, which greatly enhances both SHG effects and birefringence. (3) Iodate anions can be condensed into polynuclear iodate anions with a higher density of I5+ per unit cell, hence polyiodate anions can serve as excellent SHG-active groups. We developed a novel synthesis method for hydrothermal reactions under a phosphoric acid medium and obtained a series of metal polyiodates with strong SHG effects. In addition, as the number of iodate groups increases, the structural configuration of the polyiodate anion changes from linear to bent. (4) We introduce the concept of aliovalent substitution which features site-to-site atomic displacement at the structural level. Such aliovalent substitution led to new materials that have the same chemical stoichiometries or structural features as their parent compounds. Thus, aliovalent substitution can provide more experimental opportunities and afford new high-performance SHG materials. The introduction of a fluoride anion and the replacement of metal cations in the MO6 octahedron can result in new metal iodates with balanced properties including a large SHG effect, a wide band gap, and a high laser-induced damage threshold (LIDT) value. Finally, we briefly discuss several problems associated with the studies of SHG materials and give some prospects for SHG materials in the future.
103 citations
28 citations
TL;DR: In this article, two new potassium lead(II) hydroisocyanurates, namely, K2Pb(H2C3N3O3)4 (H2O)4 and K3PbO11(H 2O)6]17− anionic layers, were reported, which achieved moderate SHG response of approximately 2.6 × KDP with a type I phase-matching behavior under 1064 nm laser radiation.
Abstract: Cyanurate motifs are emerging functional basic blocks (FBBs) for nonlinear optical (NLO) materials and birefringent materials. Herein, we report two new potassium lead(II) hydroisocyanurates, namely, K2Pb(H2C3N3O3)4(H2O)4 (I) and K3Pb(H2C3N3O3)5(H2O)6 (II). I and II belong to acentric Cm and centric C2/m, respectively. Compound I features a novel 3D network formed by 2D [K2PbO8(H2O)4]12− anionic layers interconnected by (H2C3N3O3)− anions. The 2D [K2PbO8(H2O)4]12− anionic layer is composed of 1D chains of edge-sharing K(1)O6 and K(2)O8 being further interconnected by 8-coordinated Pb2+ ions. Compound II exhibits a characteristic 3D framework based on 2D [K3PbO11(H2O)6]17− anionic layers interlinked through (H2C3N3O3)− groups, and the 2D [K3PbO11(H2O)6]17− anionic layer is based on K–O/H2O chains bridged by Pb2+ ions. Powder second harmonic generation (SHG) measurements of I revealed a moderate SHG response of approximately 2.6 × KDP with a type I phase-matching behavior under 1064 nm laser radiation. Theoretical calculations of I and II revealed their birefringence to be 0.325 and 0.193@532 nm, respectively. Their impressive optical properties mainly stem from stereochemically active lone pair (SCALP) Pb2+ cations and the planar π-conjugated (H2C3N3O3)− groups.
21 citations
TL;DR: In this paper, Ba3Sb2(PO4)2]3-chain structure separated by Ba2+ cations with Cd2+ located at the interlayer space.
Abstract: Two new antimonous phosphates, namely Ba3Sb2(PO4)4 and Cd3Sb2(PO4)4(H2O)2, have been successfully prepared through mild hydrothermal reactions. Ba3Sb2(PO4)4 features a 1D [Sb(PO4)2]3- chain structure separated by Ba2+ cations while Cd3Sb2(PO4)4(H2O)2 presents a 2D [Sb(PO4)2]3- layered structure with Cd2+ located at the interlayer space. The [Sb(PO4)2]3- chain in Ba3Sb2(PO4)4 is the first example of 1D antimonous phosphate structure, and Cd3Sb2(PO4)4(H2O)2 represents the first d10 transition metal antimonous phosphate. Based on UV-vis-NIR spectra, both Ba3Sb2(PO4)4 and Cd3Sb2(PO4)4(H2O)2 can display large optical band gaps (4.30 and 4.36 eV, respectively). But their transparent ranges are quite different because of the coordination water of Cd3Sb2(PO4)4(H2O)2 (500-2000 and 500-1300 nm for Ba and Cd compounds). The anhydrous Ba3Sb2(PO4)4 shows high thermal stability in the nitrogen atmosphere (900 °C). Because of the incorporation of the lone pair cation of Sb(III), the birefringence of Ba3Sb2(PO4)4 and Cd3Sb2(PO4)4(H2O)2 has been enhanced to 0.086 and 0.053 at 532 nm, respectively.
21 citations
TL;DR: Results signify that [GaF(H2O)][IO3F] is a promising nonlinear optical (NLO) crystal and proposes that anisotropic polycation substitution is an effective approach to optimize the SHG effect and develop excellent NLO materials.
Abstract: A novel salt-inclusion fluoroiodate [GaF(H2O)][IO3F] derived from CsIO2F2 was ingeniously obtained through anisotropic polycation substitution. Because the catenulate [GaF(H2O)]2+ framework serves as a template for the favorable assembly of the polar [IO3F]2− groups and contributes to the nonlinear coefficient, [GaF(H2O)][IO3F] exhibits a greatly improved second-harmonic generation (SHG) effect of 10 times that of KH2PO4 (KDP) and a considerable band gap of 4.34 eV compared to the parent compound CsIO2F2 (3 × KDP, 4.5 eV). Particularly, to the best of our knowledge, [GaF(H2O)][IO3F] has the largest laser-induced damage threshold (LDT) of 140 × AgGgS2 of the reported iodates. All these results signify that [GaF(H2O)][IO3F] is a promising nonlinear optical (NLO) crystal. This work also proposes that anisotropic polycation substitution is an effective approach to optimize the SHG effect and develop excellent NLO materials.
20 citations
TL;DR: LiGaF2(IO3)2 as discussed by the authors is a mixed alkali-metal gallium iodate-fluoride, which was successfully obtained under hydrothermal conditions.
Abstract: The first mixed alkali-metal gallium iodate-fluoride, namely, LiGaF2(IO3)2, was successfully obtained under hydrothermal conditions. The structure of LiGaF2(IO3)2 features a novel two-dimensional (2D) [GaF2(IO3)2] layer composed of [Ga2F4(IO3)6]4 dimers further bridged by (IO3) groups. LiGaF2(IO3)2 exhibits a wide band gap of 4.33 eV, corresponding to the ultraviolet (UV) absorption edge of 230 nm. Calculations of linear optical property revealed that LiGaF2(IO3)2 has a remarkably large birefringence of 0.181 @1064 nm and 0.206@532 nm, indicating that it is a potential birefringent material that could be used from visible to UV region. This study provides a new method for the future discovery of promising optical crystals.
19 citations
TL;DR: A new bismuth-containing boroselenite, Bi2[B2(SeO3)6], has been obtained through high-te... as mentioned in this paper.
Abstract: Explorations of new types of borates are important because of their promising application in diverse fields. A new bismuth-containing boroselenite, Bi2[B2(SeO3)6], has been obtained through high-te...
19 citations
TL;DR: A new anhydrous rare-earth metal iodate fluoride, Ce(IO3)2F2, was rationally designed and synthesized as mentioned in this paper, which features unique zigzag ∞[CeF2]2+ chains that are bridged by IO3 groups.
Abstract: A new anhydrous rare-earth metal iodate fluoride, Ce(IO3)2F2, was rationally designed and synthesized. Ce(IO3)2F2 features unique zigzag ∞[CeF2]2+ chains that are bridged by IO3– groups, creating a...
16 citations
TL;DR: In this paper, two new yttrium sulfate tellurites, namely, Y3(TeO3)2(SO4)2 (OH)(H2O) and Y2(Te4O10)(SO4), were achieved in exploration of new sulfate tellsurites.
Abstract: Two new yttrium sulfate tellurites, namely, Y3(TeO3)2(SO4)2(OH)(H2O) and Y2(Te4O10)(SO4), were achieved in our exploration of new sulfate tellurites, with a large birefringence in the Y3+–Te4+–SO42− system. The two compounds exhibit two new three dimensional (3D) frameworks composed of different yttrium tellurite layers bridged by sulfate tetrahedra. The tellurite groups in Y2(Te4O10)(SO4) polymerized together into a unique (Te4O10)4− 1D double-strand with an eight-member polyhedral ring tunnel along the a-axis. Optical diffuse reflectance spectra showed that the two compounds present a wide energy band gap with Eg values of 4.4 and 4.1 eV respectively. The birefringence values of Y3(TeO3)2(SO4)2(OH)(H2O) and Y2(Te4O10)(SO4) were calculated to be 0.092 and 0.149 at 532 nm respectively. Furthermore, the anhydrous Y2(Te4O10)(SO4) features a large birefringence, wide energy band gap and high thermal stability. In addition, the IR spectrum, TG-DSC curve and theoretical calculations of the title compound were recorded in this paper.
15 citations
TL;DR: In this article, the authors introduce the recent developments in fluoride selenite and tellurite SHG materials together with highlighting their contributions, including Se(IV and Te(IV) compounds with (i) d0 transition metal oxyfluoride octahedron, (ii) IIIA metal oxy fluoride octanet, and (iii) other fluoride polyhedron.
12 citations
TL;DR: In this article, a new SHG material, Ba3[Al(PO4)3], has been designed by expanding the anionic condensation design strategy from atom-sharing to anionic-group sharing.
Abstract: A new SHG material, Ba3[Al(PO4)3], has been rationally designed by expanding the anionic condensation design strategy from atom-sharing to anionic-group-sharing. As the first Ba3[B(PO4)3]-type acentric phosphate, Ba3[Al(PO4)3] is characterized by moderate second-order optical nonlinearity, beneficial type I phase-matching behavior, deep-UV transparency and high thermal stability, favourable for practical applications.
TL;DR: In this article, the authors explore inorganic solids with large birefringence in the d10 Metal-Te4+−SO42− system and obtain four new sulfate tellurites.
TL;DR: In this paper, two alkali tin(II) phosphates, namely, Rb[SnF(HPO4)] and Rb(Sn3O)2(PO4)3, were synthesized through mild hydrothermal methods.
Abstract: Two alkali tin(II) phosphates, namely, Rb[SnF(HPO4)] and Rb(Sn3O)2(PO4)3, were synthesized through mild hydrothermal methods. They belong to the orthorhombic Pnma and Pbcn space groups, respectively. Rb[SnF(HPO4)] features a layered structure based on 1D [SnF(HPO4)]∞ chains interconnected by hydrogen bonds, with Rb+ cations located at the interlayer space. For Rb(Sn3O)2(PO4)3, each pair of [Sn3O]4+ clusters is bridged by a pair of [P(1)O4]3- tetrahedra to build a 1D [Sn-P-O]∞ chain. These 1D [Sn-P-O]∞ chains are further cross-linked though [P(2)O4]3- tetrahedra to construct a 3D network with 7- and 10-membered-ring channels. The tin(II) ions in Rb[SnF(HPO4)] and Rb(Sn3O)2(PO4)3 with stereochemically active lone pairs (SCALPs) significantly enhance the birefringences of metal phosphates: Δn = 0.147@1064 nm for Rb[SnF(HPO4)] and 0.082@1064 nm for Rb(Sn3O)2(PO4)3.
TL;DR: In this article, two bismuth iodate sulfates were synthesized via solvothermal reactions, namely, Bi(IO3) and CdBi(IO(SO4)2, and they exhibited wide band gaps of 3.91 and 4.03 eV and large birefringence values of 0.087 and 0.100 at 1064 nm, respectively.
Abstract: Two bismuth iodate sulfates crystallizing in the monoclinic space group P21/c, namely, Bi(IO3)(SO4) and CdBi(IO3)(SO4)2, were synthesized via solvothermal reactions. Bi(IO3)(SO4) features 2D [Bi(SO4)]+ layers, which are further linked by the IO3− groups to form a 3D network. CdBi(IO3)(SO4)2 exhibits 1D [IO3]− chains built from IO43− groups via corner-sharing and is the first example of a polyiodate sulfate as far as we know. These [IO3]− chains are interconnected by Bi3+ cations into [Bi(IO3)]2+ layers parallel to the bc plane, whereas the neighbouring Cd2+ cations are interconnected by bridging SO42− anions into [Cd(SO4)2]2− layers, also parallel to the bc plane. These cationic and anionic 2D layers are held together through Bi–O–S bridges into a complicated 3D framework. Bi(IO3)(SO4) and CdBi(IO3)(SO4)2 show wide band gaps of 3.91 and 4.03 eV and large birefringence values of 0.087 and 0.100 at 1064 nm, respectively. Our work indicates that the introduction of iodate group and lone pair cations, such as Bi3+, into metal sulfates can greatly enhance their birefringent properties.
TL;DR: In this paper, the blue light-emitting materials are commonly obtained by doping rare-earth metal ions, and considering the high price, non-rst-order rare earth metal ions are not considered.
Abstract: Playing a crucial role in light-emitting diode (LED) illumination sources, the blue light-emitting materials are commonly obtained by doping rare-earth metal ions. Considering the high price, non-r...
TL;DR: In this article, a noncentrosymmetric iron-iodate-fluoride Ba2[FeF4(IO3)2]IO3 was obtained based on the centroid-smmetric Ba[FeFeF 4(IO 3] through chemical tailoring.
TL;DR: An organic-inorganic hybrid polyiodate, namely, [o-C5 H4 NHOH]2 [I7 O18 (OH)]⋅3 H2 O (I), has been obtained by evaporation method as discussed by the authors.
Abstract: An organic-inorganic hybrid polyiodate, namely, [o-C5 H4 NHOH]2 [I7 O18 (OH)]⋅3 H2 O (I), featuring a novel branched polyiodate chain has been obtained by evaporation method. [o-C5 H4 NHOH]2 [I7 O18 (OH)]⋅3 H2 O (I) crystalizes in the polar space group Ia and features an [I7 O18 (OH)] ∞2- branched polyiodate chain in which [I3 O9 ]3- trimers are grafted on the same side of the one-dimensional (1D) chain based on [I4 O11 (OH)]3- tetramers. The asymmetric organic amine groups are beneficial to the polymerization of iodate groups and inducing the formation of the non-centrosymmetric (NCS) structure. Compound I exhibits a rather large Second-Harmonic- Generation (SHG) signal of 8.5×KH2 PO4 (KDP) upon 1064 nm laser radiation, a moderate band gap of 3.90 eV and a high laser-induced-damage-threshold (LIDT) of 182.34 MW cm-2 , hence it is a promising new SHG material. The relationship between the structures of the organic amine groups and the overall structures has been also analyzed.
TL;DR: The first IIIA metal boroselenite, M(B(SeO3)3)H2O (M = Al, Ga), was synthesized by hydrothermal reactions as mentioned in this paper.
Abstract: Exploration of new types of borates is important because of their promising applications in diverse fields. Two new boroselenites, namely, M(B(SeO3)3)H2O (M = Al, Ga), which represent the first IIIA metal boroselenite, were synthesized by hydrothermal reactions. M(B(SeO3)3)H2O (M = Al, Ga) possesses a unique sandwich like double-layer structure formed by two 2D [MSe2O8]5− layers interconnected by 1D [BSeO5]3− chains. More interestingly, both compounds display large band gaps (4.86/4.79 eV) and moderate birefringences (Δn = 0.063/0.064 at 1064 nm) based on density functional theory (DFT) calculations.