Novel electroluminescent cationic polyelectrolyte based on poly[(fluorene-2,7-diylvinylene)-alt-(1,4-phenylenevinylene)] and its precursor

作者：Mikroyannidis John A^*; Barberis Vasilis P; Cimrova Vera

来源：Journal of Polymer Science Part A: Polymer Chemistry , 2007, 45(6): 1016-1027.

DOI：10.1002/pola.21866

• conjugated polymers
• electrochemical properties
• electroluminescence
• Heck polymerization
• light-emitting diodes
• light-emitting polymer
• photophysics
• polyelectrolyte
• poly[(fluorene-2,7-vinylene)-alt-(1,4-phenylenevinylene)] derivative
• synthesis

A novel conjugated poly[(fluorene-2,7-vinylene)-alt-(1,4-phenylenevinylene)] derivative 2 with quaternizable tertiary amino groups was synthesized by Heck coupling of a substituted 2,7-dibromofluorene and 1,4-dialkoxy-2,5-divinylbenzene. The corresponding quaternary ammonium cationic polyelectrolyte 3 was obtained by the treatment of 2 with bromoethane. Both polymers were soluble in common organic solvents, like tetrahydrofuran, chloroform, and dichloromethane. Polymer 3 showed a limited solubility in alcohols and was insoluble in water. Photophysical and electro-chemical properties of the resulting polymers were fully investigated. An intensive green photoluminescence (PL) with maxima at 550 and 545 nm was observed from thin films of 2 and 3 polymers, respectively, red-shifted compared with the PL emission spectra measured in the solution. The electrochemical band gaps were 2.38-2.45 eV Single-layer and double-layer (with poly[3,4-(ethylenedioxy)thiophene]/poly (styrenesulfonate) (PEDOT:PSS)) light-emitting devices (LEDs) with ITO and Al electrodes were prepared and studied. They emitted a green light and their electroluminescence (EL) spectra were similar to those of PL thin films. The external EL efficiency was determined to be 0.43 and 0.32% for ITO/PEDOT:PSS/2/Al and ITO/ PEDOT:PSS/3/Al LEDs, respectively.

• 出版日期2007-3-15