The Study Of Controlled Construction And Photonic Properties Of Broadband Tunable MOFs Microcrystals

For the past few years,photoelectric functional materials have gained extensive research interest due to their excellent photonic properties.As science and technology develop,a variety of new kinds of optoelectronic functional materials have been developed to meet the optical functional requirements in different fields.Among them,the wide-spectrum tunable optoelectronic functional materials are important in many fields.At present,most of the wide spectrum adjustable photoelectric functional materials are composed of pure inorganic materials or pure organic materials.However,the relatively fixed band gap of inorganic materials hinders the realization of spectral modulation.At the same time,the flexible characteristics of the organic optoelectronic material structure make it face complex challenges when it is integrated into a wide-spectrum tunable optoelectronic functional material.In recent years,Due to its excellent structural characteristics,metal-organic framework(MOFs)microcrystals have become one of the hot research topic in the field of photoelectric functional materials.MOFs material is a kind of organic-inorganic hybrid material,it not only has many luminous centers,but also has abundant energy levels.In recent years,it has become an ideal carrier for modulating spectral signals.In this paper,we design and synthesize three kinds of MOFs microcrystalline materials with different element composition and spatial structure based on the construction of wide-spectrum tunable micro-nano optical functional materials.Considering their different structural characteristics,these MOFs microcrystals were prepared into optoelectronic functional materials with wide spectrum adjustable,we then tested their photonic properties and applications with pulsed lasers and fluorescence spectrometers.The main works are summarized below:(1)Research on the controllable construction and photonic performance of the wide-spectrum tunable perovskite quantum dots@MOFs micro-nano laser.Broad-spectrum tunable micro-nano lasers are an indispensable part of the integration of various photonic devices.In recent years,micro-nano lasers based on perovskite quantum dots have become the ideal material for constructing wavelength-tunable micro-nano lasers due to their unique optoelectronic properties.However,the preparation of these perovskite quantum dot lasers usually requires an external resonator to meet the optical feedback required for gain,which will inevitably lead to the destruction of the intrinsic properties of the quantum dots.In response to the above problems,we used a one-step self-assembly method to convert them into luminescent perovskite quantum dots(PQDs)in-situ within the intrinsic Pb-MOFs,and further designed them as PQDs@MOFs random lasers.The orderly arrangement of Pb²⁺nodes in the three-dimensional framework of MOFs provides enough generating sites for the construction of perovskite quantum dots,and thus provides sufficient gain for the low pump threshold lasing behavior of PQDs@MOFs random lasers.In addition,by modulating the chemical composition of the perovskite quantum dot precursor in the nano-hole environment of the MOF nanostructure,wide spectrum modulation of PQDs@MOFs random laser is realized in the whole visible light range.This work shows great potential in speckle-free imaging.(2)Research on the controllable construction and photonics performance of the wide-spectrum dynamic tunable MOFs micro-nano laser.With the continuous progress of scientific research,many achievements have been made in the construction of wide-spectrum tunable micro-nano lasers.However,the spectrum control of these micro-nano lasers is mostly static control.In order to realize the wide spectrum modulation of optical devices,it is usually necessary to integrate multiple devices with specific emission wavelengths together to realize the wide spectrum tuning function.Dynamic wide spectrum tunable micro/nano lasers have been widely used in many fields for its superior character.Therefore,the rational development and construction of controllable and dynamic-tunable micro-nano lasers is urgent.However,traditional optical gain materials often have a relatively fixed band gap,which limits their application in the construction of wide-spectrum dynamically adjustable micro-nano lasers.In recent years,some organic laser dye,which with intramolecular charge transfer property(ICT),have become the dominant materials for the construction of wide spectrum dynamic tunable micro/nano lasers rapidly due to their abundant excited state energy levels and flexible design.However,the aggregation of ICT molecules leads to a serious problem of quenching.In response to this problem,we designed and prepared bio-MOF-100microcrystalline materials with large pore sizes through self-assembly methods,and encapsulated laser gain dye molecules with intramolecular charge transfer properties in their nanopores through ion exchange.As a porous framework structure,MOFs have a certain internal environment that is responsive to external stimuli.We use continuous thermal stimulation to the external environment to control the excited state process of the gain molecules encapsulated in the microcrystalline pores of the metal-organic framework,so that the random laser spectrum of the prepared composite device has good reversible tunability.In this work,the photoelectric functional materials prepared based on MOFs have excellent photonic properties.(3)Research on the controllable construction and photonic properties of wide-spectrum dynamic tunable lanthanide MOFs heterojunction photonic barcode.The above work utilizes the pore structure of MOFs to beneficially encapsulate ICT organic gains,to achieve controllable dynamic tuning in a wide spectrum,we adjusted its excited state energy levels by temperature stimulation.The broad-spectrum modulation of the optoelectronic functional device constructed by the above work is mainly based on the guest gain molecule.However,the interaction between the guest gain molecule and the MOFs matrix is weak,which leads to its insensitivity to external stimulus regulation.The uneven distribution of the guest organic molecules encapsulated into the pores of MOFs by ion exchange will further affect the fineness of tuning the spectra of optoelectronic functional devices,resulting in greatly restricted application expansion in related fields.In response to this problem,we propose a strategy to construct optoelectronic functional devices by using intrinsic lanthanide MOFs with characteristic luminescence spectra and sharp spatially distinguished colors to achieve broad-spectrum tuning performance by regulating the energy transfer process between their photoactive centers.We designed and prepared(Tb³⁺/Eu³⁺)polychromatic heterogeneous crystallites with bimetallic junctions through the heterogeneous growth method.Since the intermolecular interactions of different photoactive centers in MOFs can be adjusted by external stimuli,by manipulating the energy transfer process between the two lanthanide elements through thermal stimulation,this work can accurately control the spectral changes of heterogeneous MOFs microcrystals,and make their spatial color have obvious stimulation-responsive.According to the changes of their characteristic spectrum,we can create a spatially responsive photon barcode.In addition,by designing multiple responsive chemical modules in a single heterostructure,the safety factor of photonic barcodes can be further improved.This work will open up a new path for the purposeful design of highly integrated responsive microstructure devices.