Browsing by Author "Vellis, Panagiotis D."

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Synthesis of Terpyridine Ligands and Their Complexation with Zn(2+) and Ru(2+) for Optoelectronic Applications
(2008-12-01)
Vellis, Panagiotis D.
;
Mikroyannidis, John A.
;
Lo, Chih-Nan
;
Hsu, Chain-Shu
;
應用化學系
A series of soluble conjugated ligands TT, FT, PT, and NT that contained terpyridyl terminal units were synthesized by Heck coupling. These ligands absorbed at 341-434 nm and emitted blue-green light, with maximum at 440-522 nm and photoluminescence quantum yields of 0.15-0.71 in solution. The double-layer electroluminescent devices with the configuration of ITO/PEDOT/ligand FT, PT, or NT/Ca/Al exhibited a brightness of 43-63 cd/m(2). These ligands were further reacted with zinc(II) and ruthenium(II) ions and subsequent anion exchange to afford linear and supramolecular complexes. The photophysics of these complexes were investigated. A significant redshift of the emission maximum of the Zn complexes relative to the corresponding ligands was observed. The Ru complexes were used to fabricate photovoltaic devices with the structure ITO/PEDOT/Ru complex/P3HT:PCBM (1:1 wt/wt)/Ca/Al. The power conversion efficiency of these polymer-fullerene bulk heterojunction photovoltaic devices was up to 0.71%. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46:7702-7712,2008
Synthesis of Terpyridine Ligands and Their Complexation with Zn2+ and Ru2+ for Optoelectronic Applications
(2008-12-01)
Vellis, Panagiotis D.
;
Mikroyannidis, John A.
;
Lo, Chih-Nan
;
Hsu, Chain-Shu
;
應用化學系
A series of soluble conjugated ligands TT, FT, PT, and NT that contained terpyridyl terminal units were synthesized by Heck coupling. These ligands absorbed at 341-434 nm and emitted blue-green light, with maximum at 440-522 nm and photoluminescence quantum yields of 0.15-0.71 in solution. The double-layer electroluminescent devices with the configuration of ITO/PEDOT/ligand FT, PT, or NT/Ca/Al exhibited a brightness of 43-63 cd/m(2). These ligands were further reacted with zinc(II) and ruthenium(II) ions and subsequent anion exchange to afford linear and supramolecular complexes. The photophysics of these complexes were investigated. A significant redshift of the emission maximum of the Zn complexes relative to the corresponding ligands was observed. The Ru complexes were used to fabricate photovoltaic devices with the structure ITO/PEDOT/Ru complex/P3HT:PCBM (1:1 wt/wt)/Ca/Al. The power conversion efficiency of these polymer-fullerene bulk heterojunction photovoltaic devices was up to 0.71%. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46:7702-7712,2008
Synthesis, Electroluminescence, and Photovoltaic Cells of New Vinylene-Copolymers with 4-(Anthracene-10-yl)-2,6-Diphenylpyridine Segments
(2010-01-15)
Mikroyannidis, John A.
;
Vellis, Panagiotis D.
;
Yang, Sheng-Hsiung
;
Hsu, Chain-Shu
;
應用化學系
Three new soluble vinylene-copolymers F, C, and P that contain 4-(anthracene-10-y1)-2,6-diphenylpyridine as common segment and fluorene, carbazole, or phenylene, respectively, as alternating segment were prepared by Heck coupling. The glass transition temperature was high for F and C (11.0 and 117 degrees C), whereas was lower than 25 degrees C for P. The polymers were stable up to similar to 300 degrees C. They emitted blue-green light with maximum located at wavelength of 456-550 nm, which was of the order F < C < P. The photoluminescence quantum efficiency in THF solution was similar to 30% for F and P and only 5% for C. All three copolymers were used as active layers for polymer light emitting diodes (PLEDs) and organic photovoltaic cells. The double PLEDs with configuration of indium-tin oxide (ITO)/poly(ethylenedioxythiophene (PEDOT) : poly(styrenesulfonate)(PSS) /Copolymer F, C, or P/TPBI(1,3,5-tris(2-N-phenylbenzimidazolyl)benzene)/Ca/Al were fabricated. Copolymer P emitted green light with maximum brightness of 28 cd/m(2) and a current yield of 0.85 cd/A. Organic photovoltaics with the configuration of ITO/PEDOT : PSS/Copolymer and [6,6]-phenyl-C61-butyric acid methyl ester blend (1 : 1)/Ca/Al were also fabricated. Copolymer P showed the highest power conversion efficiency of 0.034%. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 731-739, 2010