Synthesis And Properties Of A Carbazol-Triarylboron Fluorescent Material With AIE Characteristic

In fields such as flat-panel displays and solid-state lighting,organic light-emitting diodes?OLEDs?have the advantages of active lighting,high brightness and low power consumption.Therefore,OLEDs stand out among many display technologies and are favored by people.In the actual device preparation,well-performing organic luminescent materials are required to produce excellent OLEDs devices,and the core component of OLEDs is the luminescent layer.However,traditional luminescent materials when they are used in the form of solid-state films for the luminescent layer of OLED devices will result in the phenomenon of aggregation caused quenching?ACQ?,which seriously affects the practical application of luminescent materials in OLEDs devices.In 2001,researchers discovered a luminescent material that barely observed fluorescence in solution,but when the concentration of the solution increased when it was in a aggregation state,fluorescence was observed to be stronger.They define this type of material as aggregation-induced emission?AIE?materials,which can make up for the shortcomings of traditional luminescent materials and promote the practical application of luminescent materials in OLEDs.After that,the researchers devoted themselves to the synthesis of aggregation-induced emission?AIE?materials,and used them as luminescent layers to make highly efficient and stable OLEDs.However,among many aggregation-induced emission?AIE?materials,there are few blue luminescent materials that can be used to construct high-efficiency OLEDs devices.By analyzing various types of photoelectric material,we have found that carbazole and its derivatives with excellent hole-transporting property is an important fluorescent material for the preparation of blue OLEDs devices.Triarylboranes is a class of photoelectric materials that emit light efficiently in solution and solid state.In this thesis,we successfully synthesized a new blue fluorescent material with AIE characteristic by introducing carbazole and triarylborane groups to the same molecule.Then,in order to better understand the performances of this material,we characterized the structure of this compound first and then tested and analyzed AIE,electrochemical and electroluminescent properties of the compound systematically.The concrete includes the following aspects:1.Based on related literatures,we briefly introduced the development,structure,materials and luminescence principle of OLEDs devices,and summarized the development history,luminescence mechanism and molecular type of aggregation-induced emission materials.On the basis of these,the design idea of this dissertation was put forward.2.We synthesized a new blue fluorescent material DBBPBCZ of carbazole-triarylboron with AIE characteristic.The synthesis of the AIE-active compound involves Suzuki reaction,coupling reaction.Then,the structure of the compound DBBPBCZ was adequately characterized by ¹H NMR and ¹³C NMR.3.The properties of DBBPBCZ were tested by UV-vis absorption spectra,electrochemistry and TGA.We have found that DBBPBCZ is a excellent fluorescent material with remarkable AIE characteristic.Finally,we construct an non-doped OLED device based on the compound DBBPBCZ and its electroluminescent performance was systematically tested and analyzed.The test results show that the OLED exhibits a bright deep blue emission with a turn-on voltage of 5.6 V,a maximum current efficiency??C,max?of 1.129 cd A^-1,and a maximum luminance(L_max)of 4479 cd m^-2.This result indicates that the blue OLED prepared by DBBPBCZ has high luminous efficiency and can be applied to actual production.The synthesis of DBBPBCZ not only expands the existing AIE materials,but also fills the more scarce blue fluorescent materials.It can also provide a new idea for researchers to design new blue light AIE molecules in the future.