Controllable Synthesis And Photonic Properties Of Host-Guest Metal-Organic Framework Hybrid Single Crystals

Micro-nano photonics is essentially a discipline that studies the interaction between light and matter in the micro-nano scale.It not only opens up new fields for basic research,but also creates opportunities for the birth and development of high-tech,which covers many fields such as physics,chemistry,materials science,electronic informatics and biomedicine.As a new class of ordered porous crystalline hybrid materials,metal-organic frameworks(MOFs)have become an extremely powerful assembly platform for many functional ions or molecules.Photonic functional MOFs have become an important research direction due to their ability to combine photonics properties with the unique advantages of ordered microporous framework materials.In photonic-functional MOFs,although a small number of inorganic metal ions and organic bridging ligands themselves can provide photonic functions,the range of choice and the performance that can be expressed are very limited.Aiming at this scientific problem and based on the design strategy and advantages of host-guest MOFs,this thesis proposes a design scheme that the highly disignable framework and pore structure of MOFs are used as the host to provide spatial confinement and orientation to the guest with rich photoinic properties,and to controllably synthesize the hybrid crystalline material with novel photonic function.This thesis further explores and studies the unique photonic properties of the resulting hybrid single crystals,and expands the potential application of MOFs in the field of photonics.These findings provide important experimental and theoretical basis for the host-guest MOFs based hybrid microcrystals in high-polarization and multi-color microlasers,and high-order multiphoton excitation frequency upconversion emission.A new anionic MOF crystal H2[2Zn3O(CPQC)3](ZJU-68,ZJU = Zhejiang University)with sub-nanoscale one-dimensional(1D)channels was designed by using zinc ion and a novel multidentate organic bridging ligand 7-(4-carboxylic acid phenyl)-3-carboxylic acid-quinoline(H2CPQC).The in-situ assembly method successfully controlled the chromophore ion 4-[p-(dimethylamino)styryl]-1-methylpyridine(DMASM)with unidirectional transition dipole moment to assemble into channels of ZJU-68,thus resulting the host-guest hybrid single crystal ZJU-68(?)DMASM.The periodic physical and chemical environment and high-efficiency spatial confinement of ZJU-68 1D ordered channels make the DMASM in the hybrid single crystals highly concentrated and periodically arranged,thus achieving high optical gain and highly ordered transition dipole moment.Via the high-quality smooth crystal morphology of ZJU-68 acted as the micro-resonator and the anisotropic emission characteristics provided by the ordered orientation of the transition dipole moment,the hybrid single crystal achieves single-mode linearly polarized microcavity lasing excited by single photon(532 nm)and two-photon(1064 nm),with lasing thresholds(Eth)of 217 ?J/cm2 and 7.30 mJ/cm2,respectively.High-order(n?3)multiphoton pumped polarized microlasers have important application prospects in biophotonics such as bioinformatics imaging and photodynamic therapy.However,materials with relevant properties have not been realized.Based on the above-mentioned in-situ assembly and highly oriented arrangement of DMASM provided by the spatial confinement of ZJU-68 channels,the assembly concentration of DMASM was further adjusted to increase the photoluminescence quantum yield(PLQY)from 0.45%of DMASM solution to 24.28%,In addition,the natural crystal facets of ZJU-68 single crystal can be efficiently used as the mirror of the resonant cavity.For the first time,the three-photon pumped solid-state microlasing with high degree of polarization(>99.9%),low Eth of 31.7 mJ/cm2 and high quality factor Q of up to?1691 was realized in the hybrid single crystal ZJU-68(?)DMASM.These findings provide a new approach and theoretical basis for the design and preparation of novel multiphoton pumped polarized microcavity laser materials and devices.When homo-epitaxially growing the host framework ZJU-68 on the host-guest hybrid crystal ZJU-68(?)DMASM,another chromophore ion(E)-1-methyl-4-(2-(1-methyl-1H-pyrrolyl)vinyl)pyridine(MMPVP),which also has a unidirectional transition dipole moment,is assembled in situ to successfully prepare the hierarchical hybrid crystal ZJU-68(?)DMASM+MMPVP with two-color emission.Under 480 nm excitation,the hybrid crystal segments show red and green light,respectively,which also exhibit remarkable fluorescence anisotropy.Combining a natural high quality and smooth crystal surface effectively actting as a laser cavity,for the first time the hierarchical hybrid single microcrystal exhibits a low-threshold two-color single-mode polarized lasing output with the degree of polarization is greater than 99.9%at room temperature.These findings provide a new way to develop multi-color solid-state microlaser materials for future multimodal bioinformatic imaging.The above ZJU-68(?)DMASM obtained by the precise matching of the chromophore molecule and the MOF pore structure only realized three-photon excited luminescence,and the higher-order multiphoton excited(MPE)crystalline luminescent material has not yet been realized.Organic-inorganic hybrid perovskite quantum dots(QDs)are very promising high-order nonlinear upconversion luminescent materials,however their stability in air is very poor.Herein we show the up to five-photon excited luminescence in a host-guest MOF and perovskite-quantum dots(QDs)hybrid single crystal ZJU-28=DMAPbBr3(ZJU-28 =(Me-NH2)3[In3(BTB)4];BTB = 1,3,5-benzenetribenzoate;MA = CH3NH3+)via an in-situ growth approach.Such MOF strategy not only results in a high QDs loading concentration,but also significantly diminishes the aggregation-caused quenching(ACQ)effect,provides effective surface passivation,and greatly reduces the contact of the QDs with the external bad atmosphere due to the confinement effect and protection of the framework.These advantages make the resulting ZJU-28(?)MAPbBr3 single crystals possess high PLQY of?51.1%,high multiphoton action cross-sections that can rival the current highest record(measured in toluene solution),and excellent photo-stability.These findings liberate the excellent luminescence and nonlinear optical properties of perovskite QDs from the solution system to the solid single crystal system,which provide a new avenue for the exploitation of high-performance multiphoton excited hybrid single microcrystal for future optoelectronic and micro-nano photonic integration applications.Single crystal perovskite microplates are fundamentally and technologically very important to developing high-order multiphoton excitation.In addition to the use of MOFs to load perovskite quantum dots,herein we report the preparation of high-quality single crystal perovskite microplates through the controlled release of lead ions from the confined species within a MOF.The resulting free-standing MAPbBr3 and CsPbBr3 single crystals of rectangular microplates exhibit excellent multiphoton excitation behaviors,as demonstrated in their five-photon-excited photoluminescence and three-photon-pumped stimulated emission with the threshold of 200 mJ/cm2 and 159 mJ/cm2 respectively,providing the promise of exploring high-quality single crystal perovskite microplates for photonics applications.