Construction And Properties Of Organic Optoelectronic Materials Based On N-C=O Resonance Structure

As a representative of new materials,organic optoelectronic semiconductor materials play a vital role in strategic emerging industries such as flat panel displays and integrated circuits.Due to their own characteristics of flexibility,ease of processing,and stimuli response,organic optoelectronic semiconductor materials are widely used in organic light-emitting diodes(OLEDs),airport effect transistors(OFETs),organic solar cells(OSCs),chemical and biological sensors and anti-counterfeiting tags.So far,researchers have developed many organic optoelectronic semiconductor materials with excellent optoelectronic properties based on a variety of molecular design strategies.Among them,organic resonance photoelectric functional materials have shown good performance in organic electroluminescent devices and entered people’s field of vision.Compared with traditional organic optoelectronic functional materials,the resonance effect generated by organic resonance photoelectric functional materials plays an important role in regulating photoelectric properties.This paper focuses on the development and application of dynamic adaptive change resonance materials,and designs and synthesizes a series of resonant structures based on N-C=O organic optoelectronic functional materials systematically study the thermal,electrical and optical properties of materials,and further apply these materials to optical printing,multiple anti-counterfeiting encryption,and phosphorescent organic light-emitting diodes.Specific research work includes:(1)Synthesis and application of photoactivated pure polymer materials with controlled afterglowBased on molecular design containing N-C=O resonance structure,this chapter proposes a simple strategy,based on the non-doped copolymer system composed of the host pyridine and the guest(9H-carbazol-9-yl)(phenyl)methanone,through the exciton sensitization of the host unit to the guest unit,combined with the thermal annealing treatment method to achieve the transformation of the material to the glassy state,enhance the rigidity of the polymer system,and finally stabilize the trilinear exciton.The energy transfer process occurs between the host and guest elements,which greatly promotes the emission of phosphorescence while avoiding phase separation caused by doping methods such as physical blending.The use of resonance can produce more inter-system channels,and long-term photoactivation consumes the oxygen inside,so that the luminous intensity reaches saturation and produces long afterglow emissions.Among them,the life of the flake P2 was extended from 0.82 ms to 869.76 ms,an increase of 1.1×10~3 times.Taking advantage of this characteristic of light stimulation response,a variety of long afterglow patterns are obtained to achieve optical printing.(2)Synthesis and application of time-dependent afterglow of one-component materialsBy introducing the structure of N-C=O resonance,a one-component organic molecule Cz DCCOCz was designed.After stopping excitation for 1 s,its color gradually changes from purple-pink to yellow-green,and this luminous property is related to two long-life emitting sources.Fluorescence and phosphorescence with lifetimes of 188.96 and 506.28 ms,respectively,change in intensity over time over time.Experimental research and theoretical calculations show that resonance can significantly increase the interfacline channel,accumulate more trilinear excitons,and the trilinear excitons collide with each other and annihilate to produce long-lived fluorescence.Based on this material with special properties,we have built a triple encryption mode of time,color and pattern to improve the level of information security.(3)Synthesis and application of host materials based on N-C=O resonance structureA new strategy was developed to design and synthesize a novel dual-donor resonance linker-donor(D-r~2-D)by introducing a resonant group(C=O)between donors.Among them,we select carbazole or diphenylamine the donor unit to form an N-C=O resonance structure.The presence of a resonant structure facilitates the balance of the material’s transport capacity for carriers.Both materials have good thermal stability,high energy levels of triplet excited state,and suitable HOMO and LUMO energy levels.The electroluminescent device prepared as the host material obtains a maximum current efficiency of 28.5 cd/A,a maximum power efficiency of 13.6 lm/W,and a maximum outer quantum efficiency of 14.0%.These results show that the dual N-C=O resonance structure can regulate the photoelectric properties,which may be enlightening for the molecular design of new principal materials.