Synthesis Of Blue Host/orange Dopant For PhOLED And Their Electroluminescence Devices

Organic light-emitting devices(OLEDs) have the advantages of self emission, fast response and so on, which make them budding in areas of panel displays and solid-state lighting. PhOLEDs’ EQE(External quantum efficiency) could reach the theoretically possible limitation of 100%. We believe by judicious molecular design and selection, the photoelectric properties of PhOLEDs could be further improved. The research of this article focuses on the design of host and dopant materials, improvements of synthesis process and optimization of device performance.Firstly, the article introduced Naphthalen-1-yl-phenyl-amine into C^N=N ligand to synthesis new Ir complex, which has higher conjugation degree. Then we further studied the device performance based on this material.Secondly, we introduced phase transfer catalyst in our Carbon-Carbon coupling reaction. This optimization could improve synthesis yield without increasing the complexity of the process, which may benefit to mass production of photoelectric materials.Thirdly, we synthesized four pure hydrocarbon bipolar transfer host materials based on fluorene moiety, and further studied their internal reorganization energy, photophysical properties, electrochemical properties and thermal properties. By systematic study, we find that the number of fluorene substitutions, link mode and the choice of core has influence on the materials’ photophysical properties, electrochemical properties and thermal properties. Especially for pDPFDB based on biphenyl core, its Td was improved to 408℃ in nitrogen protection.Lastly, we fabricated four devices with FIrpic(Bis(4,6-difluorophenylpyridinato-N,C2) picolinatoiridium) doped into our four host materials. Simultaneously, many experiments and theory calculations are also carried out. The results show that good blue hosts could be produced, through judicious selection of fluorene substitution numbers, link mode and molecule core. Especially for the star-shape molecule mTPFB, the device based on it has maximum current efficiency and EQE of 30.56 cd/A and 15.74% and this can be attributed to its strong and balance hole and electron mobility.