Synthesis and characterization of polyfluorenevinylene with cyano group and carbazole unit

Abstract

The present investigation deals with the synthesis, characterization, and EL properties of new polyfluorenevinylenes, CzCNPFVs, with cyano‐substituted vinylene unit and carbazole pendant. In CzCNPFVs, synthesized by the Knoevenagel condensation, the carbazole pendant was introduced to improve the efficiency of reported CNPFV. The PL emission spectra of the CzCNPFVs in chloroform solution show maximum peaks at 476–479 nm. In thin films, maximum peaks of the CzCNPFVs appeared at 501–504 nm, red‐shifted around 25 nm as compared to those in solution. The emission maxima of the EL spectra of the polymers appear at around 496–504 nm. The maximum luminescence (Lmax) of CzCNPFV2 of the device with the configuration of ITO/PEDOT/CzCNPFVs/Ca/Al is 1724 cd/m2 at 8 V. The maximum luminescence efficiency of CzCNPFV1 is 0.18 cd/A. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6540–6551, 2009

Unusually high fluorescence quantum yield of a homopolyfluorenylazomethine – towards a universal fluorophore

“…28 The intense and consistent fluorescence is shown in the inset of Fig. 47,48 In fact, there is little effect of solvent polarity on the emission quantum yields of 2, especially between apolar and polar solvents (Table 1). The F fl of 2 in dichloromethane is consistent with its analogous polyvinylene derivatives such as 4, whose emission yields are approximately 50% in dichloromethane.…”

Color stability of conjugated polymer with difluoro groups in vinylene units

“…[2][3][4] Many kinds of conjugated polymers have been applied as active materials into several kinds of electronic devices. [5][6][7][8][9] Poly(p-phenylenevinylenes) (PPVs), which was discovered at Cavendish laboratory in Cambridge, became the starting point of a new area in conjugated polymer science, and has been one of the most representative classes of semiconductor polymers for electroluminescent devices. [10][11] Although PPV derivatives had been made the best use to produce the best efficiency by means of new types of device fabrication, the degradation of these PPV derivatives with vinylene units after irradiation with white light or operation of the device continues to be a problem.…”

Synthesis and characterization of blue light emitting polymers based on arylene vinylene

“…1,2 The main advantages of conjugated polymers in EL (electroluminescence) as compared to inorganic or organic materials for LEDs are low product costs, flexibility, and the possibility of fine-tuning their luminescent properties through modification of the chemical structure, as well as the feasibility of combining spin-coating and printing processes for large-area flat panel displays. [3][4][5] Efficient, thermally stable blue light emitting materials are needed both to complete the color spectrum and to serve as energy transfer media for incorporated fluorophores. Furthermore, blue light emitting polymers (LEPs) are very important for the development of cost-efficient white light emitting diodes for next-generation applications such as general light and backlight sources for LCDs.…”