Research On The Electroluminescent Prop Erties Of Twisted Styrene-functionalized Molecules And Their Devices

In this work,seven kinds of novel functionalized molecules of twisted benzene were synthesized based on pyrene,and these molecules were used as luminescent functional layer to prepare luminescent devices.Then the luminescence performance parameters such as luminous wavelength,luminous brightness and luminous efficiencyare are compared and analyzed,the relationship between different structure molecules and luminescence performance was studied,and the influence of different device preparation conditions on luminescence performance was discussed.The following results were obtained:?1?The twisted molecule 11,16-di-tert-butyl-9,18-diphenylbenzo[kl]benzo[8,9]triphenyleno[2,3-b]xanthene?BTX?was synthesized.Single crystal X-ray diffraction analysis showed that the twisted structure in this molecule could inhibit the?-stacking action of the solid phase.Self-assembly studies have shown that the solvent-volume ratio has a significant effect on the aggregation morphology and size.The maximum absorption peak of the compound in the diluted THF solution was 463 nm,and the emission peak was 473/504 nm.In the nanowire solution,the maximum absorption peak was 470 nm,and the emission peak was 480/526 nm,both have obvious redshift phenomenon.The maximum brightness of the electroluminescent device prepared with BTX as the functional layer is 4355 cd m^-2,and the current efficiency,power and external quantum efficiency are 1.7 cd A^-1,1.48 lm/W and 0.7%,respectively.?2?Two new dendritic conjugated molecules 1 and 2 with twisted topologies were synthesized.The absorption peak of compound 1 was 315/392 nm,and the emission peak in solution and film was 451 nm and 467 nm respectively.The absorption peak of compound 2was 345/435 nm,and the emission peak in solution and film was 490 nm and 532 nm,respectively.The maximum brightness of the electroluminescent device prepared with molecule 1 as the functional layer is 1010 cd m^-2,and the current efficiency,power and external quantum efficiency are 2.7 cd A^-1,2.45%and 1.75 lm/W,respectively.The maximum brightness of the electroluminescent device prepared with molecule 2 as the functional layer is20801 cd m^-2,and the current efficiency,power and external quantum efficiency are 11.1 cd A^-1,8.72 lm/W and 3.19%respectively.?3?A series of aromatic hydrocarbon molecules containing functional groups of different substituents were synthesized with pyrene as the primitive element,and electroluminescent devices of different luminous wavelengths could be prepared.The performance parameters are 4900 cd m^-22 and 0.80%EQE for devices with emission wavelength of 505 nm.The brightness of the device with emission wavelength of 550 nm was 14000 cd m^-22 and EQE was1.1%.The emission wavelength of 630 nm is 2500 cd m^-22 and EQE is 1.08%.