Preparation And Optical Application Of Micro-nano Materials Based On AIE Molecules

In modern times,the development of luminescence field has been affected by the aggregation-caused quenching(ACQ)phenomenon of substances,especially for the research and application of aggregated molecules.The discovery and proposal of the phenomenon of aggregation-induced emission(AIE)has profoundly changed the previous research situation and attracted extensive attention of researchers.With the in-depth discussion and summary of the AIE phenomenon and its mechanism,many AIE molecules have been designed and prepared to meet people’s needs for materials and devices.Organic materials have many unique advantages: rich photophysical and photochemical processes,good material compatibility,easy-regulated growth characteristics and easy-doped characteristics,and play a pivotal role in many fields.But due to the limitation of the ACQ effect,many organic molecules cannot meet the functional requirements of the devices.For example,in solid-state lasers,four-level materials with great emission properties in the aggregated-state are required as working substances;in biochemical sensors,the working environment of most fluorescent molecules is a watery or hydrophilic environment.And with the rapid development of nanophononics in recent years,nanomaterials with unique structures and size effects exhibit unlimited potential.Therefore,it is of great scientific significance and research value to prepare AIE materials at the micro-nano scale,construct optical devices,and analyze the photophysical and photochemical processes of materials.Based on the summary of the previous research contents of AIE materials,this paper attempts to select the AIE molecules with required functions based on the characteristics of the molecules.According to the understanding of the characteristics and assembly rules of organic materials,use reasonable methods to easily and efficiently control the preparation of micro-nano structures,design and construct target devices,characterize the optical properties of micro-nano structures,and analyze the roles and changes of materials during assembly and reaction.The specific main research contents include:(1)According to the requirements of gas sensors that can be visualized by the naked eye,we choose AIE molecules with carboxyl functional groups to construct ammonia gas optical sensors.In order to construct a sensing system with high sensitivity,high response and simple process,micro-nano structures such as organic thin films and single crystals are selected to be prepared.Through the exploration of parameters such as film thickness,a gas optical sensor with excellent performance was obtained,which provided a new idea for ammonia detection.The simultaneously grown micro-nano single crystal structure offers the potential to further improve the resolution and sensitivity of the sensor.Through the analysis of the reaction process between AIE molecules and ammonia molecules,the sensing mechanism of the sensor is explored,and the physical and chemical process of the interaction between organic materials and the detected gas is deeply understood.(2)In order to realize the output of micro-nano laser and avoid fluorescence quenching caused by the formation of aggregated states,we chose organic laser dyes with AIE properties.To achieve the resonance of the laser,two different optical resonators are constructed.The single-crystal nanowires with defect-free surfaces are grown by the liquid drop method,which can be used as F-P resonators.Using the emulsion self-assembly method,the organic microspheres with complete structure and smooth surfaces are obtained,and the laser output with low threshold and high quality factor are realized by dye-doping.Through the control of the two resonator size structures,the mode modulation of the laser is realized,which provides an ideal coherent light source for integrated photonic circuits and a useful reference for the integration of future photonic devices.In short,starting from the required devices and functions,select AIE materials and molecular structures with gain characteristics in the aggregated state,and prepare micro-nano materials through simple,efficient,and flexible methods.The photophysical and photochemical processes of the material provide a reference for the future optical function design and photonics research of organic AIE materials.