Synthesis,characterization, and electrogenerated chemiluminescence of deep blue emitting eumelanin‐inspired poly(indoylenearylene)s for polymer light emitting diodes

Deep blue emitting copolymers were synthesized by uniting the Eumelanin‐inspired indole core with fluorene and carbazole units via Suzuki polymerization. The resulting polymers, PIF and PIC, showed deep blue emission in the range of 416–418 nm and quantum yields of 0.39–0.60. Both polymers exhibited an intense and stable electrogenerated chemiluminescence. Interestingly, deep HOMO levels of −5.71 and −5.61 eV were observed for PIF and PIC, respectively. Solution processed polymer light emitting diodes (PLEDs) were fabricated using the PIF as a guest. PLEDs emitted deep blue light at 418 nm, with the luminous efficiency peaking at 1 Cd/A, given that the photopic response at that wavelength is 0.0151. The electroluminescence of PIF displayed a Commission Internationale de l'Eclairage coordinates of (0.16, 0.07) with a maximum external quantum efficiency of 1.1%. Hence, these materials prove to be promising candidates for the fabrication of deep blue PLEDs. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 125–131