Synthesis and characterization of stable blue light‐emitting poly(spirobifluorene) derivatives containing alkoxy group

Abstract

Polymers containing alkoxy-substituted spirobifluorene have been prepared from nickel(0)-mediated coupling or palladium-catalyzed Suzuki coupling. The polymers were characterized using various spectroscopies, such as 1 H-NMR, FT-IR, and elemental analysis. The high glass transition temperature and high decomposition temperature suggested that the resulting polymers possessed a high thermal stability. The obtained polymers possessed weight average molecular weight of 4500 -33,000 with polydispersity index of 1.1-1.9 and good solubility. The low onsets of the oxidation potential suggested that the polymers containing alkoxy substituted spirobifluorene possessed a good hole injection property. The photoluminescence and electroluminescence of the polymers containing alkoxy substituted spirobifluorene showed stable blue color by suppressing the excimer formation due to intermolecular interaction.

Synthesis and characterizations of a polyimide containing a triphenylamine derivative as an interlayer in polymer light-emitting diode

“…However, device lifetime, one of the most important factors for practical applications, still remains a serious problem for PLEDs. Especially, the lifetime of blue PLEDs [5][6][7] is still much shorter than those of green and red color PLED devices [8]. Some important reasons of the low device stability are known to be a poor interface structure, unbalanced carrier injection and other impurities diffused from both electrodes to the emitting layer [9][10][11][12][13].…”

New deep blue light emitting copolymer containing fluorene, carbazole, and dialkoxynaphthalene

“…28 The polymer has a PL quantum efficiency (40 6 10% using a dilute quinine sulfate solution as a standard). [4][5][6] Cyclic voltammetry was performed on a film of polymer, calibrated against ferrocene-ferrocenium. The oxidation peak potentials of the obtained copolymer and reported alternate copolymer were measured to be Eox ¼ 1.26 V and 1.36 V, respectively.…”

“…2,3 Full color display applications required red, green, and blue emission and whilst all three colors have been demonstrated, there are relatively few efficient and high brightness blue emission polymers. [4][5][6] Furthermore, the blue light emitting polymers (LEPs) are very important for the development of cost-efficient white LEDs for next-generation applications such as general light and backlight source for LCD. [7][8][9] Therefore, developing efficient, stable, and deep blue LEPs is essential to realize such applications.…”

Synthesis and device performance of new efficient blue copolymers containing biphenylenevinylene and triphenyldiamine

“…15,16 Thus far, numerous blue EL polymers have been investigated and developed. [17][18][19][20][21] PPV and poly(pphenylene) (PPP) are typical electroluminescent polymers used in polymer light-emitting diodes. PPV and its derivatives [22][23][24][25] are attractive because of their high thermal stability, good film quality, and suitable color tunability.…”