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Semiconducting Polymers (Semiconduct + polymer)
Selected AbstractsA Thermally Stable Semiconducting PolymerADVANCED MATERIALS, Issue 11 2010Shinuk Cho The thermal stability of the poly(2,7-carbazole) derivative (PCDTBT) is investigated. UV,visible absorption spectra and X-ray photoelectron spectroscopy data demonstrate that the electronic structure of PCDTBT is stable in air at annealing temperatures up to 150,°C and in N2 even after exposure to temperatures up to 350,°C. Field-effect transistors fabricated with PCDTBT show stable characteristics and hole mobility up to 150,°C (air) and 350,°C (N2). [source] A Wide-Bandgap Semiconducting Polymer for Ultraviolet and Blue Light Emitting Diodes,MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 18 2003Ping Lu Abstract A novel wide-bandgap conjugated polymer (PDHFSCHD) consisting of alternating dihexylfluorene and rigidly twisted biphenyl units has been synthesized. The new fluorene-based copolymer composed of rigid twisting segments in the main-chain exhibits an optical bandgap of as high as 3.26 eV, and a highly efficient ultraviolet emission with peaks at 368 nm and 386 nm. An electroluminescence device from PDHFSCHD neat film as an active layer shows UV emission which peaks at 395 nm with a turn on voltage below 8 V. By optimizing the device conditions, a peak EL quantum efficiency of 0.054% and brightness of 10 cd,·,m,2 was obtained. Furthermore, blending a poly(dihexylfluorene) in the PDHFSCHD host gave pure blue emission peaking at 417 nm and 440 nm without long wavelength emission from aggregated species. Efficient energy transfer from PDHFSCHD to PDHF was demonstrated in these blended systems. Depressed chain-aggregation of PDHF in the PDHFSCHD host can correspond to pure blue emission behaviors. The structure of the copolymer PDHFSCHD. [source] Aligned Nanofibers: Epitaxial Growth of Highly Oriented Fibers of Semiconducting Polymers with a Shish-Kebab-Like Superstructure (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 17 2009Mater. Highly oriented fibers of regioregular poly(3-alkylthiophene)s with a "shish-kebab" morphology are prepared by epitaxy on long needles of 1,3,5-trichlorobenzene grown in liquid pyridine, as described on page 2759 by Brinkmann et al. The superstructure of the fibers consists of a highly oriented thread-like core several hundreds of micrometers long, the "shish", onto which lateral crystalline nanofibrils made of folded polymer chains, the "kebabs", are connected in a periodic way. [source] Epitaxial Growth of Highly Oriented Fibers of Semiconducting Polymers with a Shish-Kebab-Like SuperstructureADVANCED FUNCTIONAL MATERIALS, Issue 17 2009Martin Brinkmann Abstract Highly oriented fibers of regioregular poly(3-alkylthiophene)s (P3ATs) showing a "shish-kebab" morphology are prepared by oriented epitaxial crystallization in a mixture of 1,3,5-trichlorobenzene (TCB) and pyridine. The superstructure of the P3AT fibers consists of an oriented thread-like core several hundreds of micrometers long, the "shish", onto which lateral crystalline fibrils made of folded polymer chains, the "kebabs", are connected in a periodic way with a periodicity in the range 18,30,nm. The P3AT-chain axis is oriented parallel to the fiber axis whereas the ,-stacking direction is oriented perpendicular to it. The oriented character of the shish-kebab fibers results in polarized optical absorption and photoluminescence. The formation of oriented precursors by epitaxial orientation of polymer chains onto long needles of a molecular crystal,TCB in the present case,appears to be an original alternative to the crystallization usually performed under external flow conditions. [source] Infiltrating Semiconducting Polymers into Self-Assembled Mesoporous Titania Films for Photovoltaic Applications,ADVANCED FUNCTIONAL MATERIALS, Issue 4 2003K.M. Coakley Abstract Interpenetrating networks of organic and inorganic semiconductors are attractive for photovoltaic cells because electron transfer between the two semiconductors splits excitons. In this paper we show that films of titania with a uniform distribution of pore sizes can be made using a block copolymer as a structure-directing agent, and that 33,% of the total volume of the film can be filled with a semiconducting polymer. [source] A Nitrogen Dioxide Sensor Based on an Organic Transistor Constructed from Amorphous Semiconducting Polymers,ADVANCED MATERIALS, Issue 22 2007A. Das Organic field effect transistors based on amorphous semiconducting polymers are used as highly effective sensors for the detection of low concentrations of NO2. The figure shows the experimental setup used to detect the toxic odor. The threshold voltage rather than the charge carrier mobility is seen to be greatly modified by exposure to NO2. [source] | ||||||||||