Several pyrene-based polyphenylene dendrimers (PYPPDs) with different peripheral chromophores (PCs) are synthesized and characterized. Deep blue emissions solely from the core are observed for all of them in photoluminescence spectra due to good steric shielding of the core and highly efficient surface-to-core Förster resonant energy transfers (FRETs). Device performances are found in good correlation with the energy gaps between the work function of the electrodes and the frontier molecular orbital (FMO) levels of the PCs. Pure blue emission, luminance as high as 3700 cd m(-2) with Commission Internationale de l'Éclairage 1931 (CIE(xy)) = (0.16, 0.21), and a peak current efficiency of 0.52 cd A(-1) at CIE(xy) = (0.17, 0.20) are achieved. These dendrimers are among the best dendritic systems so far for fluorescent blue light-emitting materials.

Nine 1,3,6,8-tetraarylpyrenes were prepared and characterized for OLED-based blue-light emission.

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A series of novel polyfluorenes, soluble exclusively in perfluorinated solvents, were prepared. The new materials were studied with regard to orthogonal processing of organic electronic materials. The desired solubility was achieved by introducing semifluorinated side chains to the fluorene monomers. Since the use of long perfluoroalkyl chains (RF) is restricted due to public health concerns, a synthetic route for polyfluorenes with short RF chains branched by aromatic units has been developed. The photophysical behavior of the resulting polymers was investigated in solution and thin films by UV/Vis absorption and photoluminescence spectroscopy. The photoluminescence quantum yields were found to be in the range of those of alkylated polyfluorenes. The electroluminescent properties were studied in single‐layer polymer light‐emitting diodes, with the new polymers as active materials, which exhibited similar characteristics to previously published single‐layer devices with polyfluorenes containing long RF. The wetting properties of different polyfluorene films containing fluorinated, polar, polyethylene glycol, or nonpolar alkyl groups were investigated by contact angle measurements.

To date, most commercially available organic light emitting diodes (OLED) are fabricated by cost extensive and material-consuming thermal vacuum deposition processes. Therefore, a switch to a solution-based fabrication strategy, albeit challenging for efficient multilayer designs, is highly desirable. The necessity for multilayer device architectures is comprehensively explained at the beginning of the chapter and the challenges arising in a solution-based process are explained. The remainder of the chapter is dedicated to the presentation of the different fabrication schemes. First, schemes that allow for the fabrication of multiple layers from the same solvents without a modification of the used organic semiconductors are detailed. Subsequently, schemes that use the same solvents but also require an alteration of the organic semiconductor are presented. Furthermore, fabrication of multiple layers from different solvents is explained. At the end a few notable approaches that combine different fabrication mechanisms are detailed. For each scheme presented within this chapter references to the literature are provided.