Browsing by Author "Yin, Jen-Fu"

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An Unprecedentedly Huge Square-Grid Copper(II)-Organic Framework Material Built from a Bulky Pyrene-Derived Elongated Cross-Shaped Scaffold
(2009-09-21)
Tsai, Chen-Chuan
;
Luo, Tzuoo-Tsair
;
Yin, Jen-Fu
;
Lin, Hong-Cheu
;
Lu, Kuang-Lieh
A new bulky pyrene-derived elongated cross-shaped organic scaffold was successfully incorporated into a highly porous, non-interpenetrated square-grid copper(II)-organic framework material with the unprecedentedly huge dimensions of 25.5 x 25.5 angstrom(2), while the layer-to-layer NH center dot center dot center dot N interaction leads to a unique hydrogen-bonded 6(4).8(2)-nbo net.
Enhanced light-harvesting capability by phenothiazine in ruthenium sensitizers with superior photovoltaic performance
(2012)
Yin, Jen-Fu
;
Chen, Jian-Ging
;
Lin, Jiann-T'suen
;
Bhattacharya, Dibyendu
;
Hsu, Ying-Chan
This paper reports on the design and synthesis of two new ruthenium dyes [Ru(dcbpy)(potip)(NCS)(2)] (JF-3, dcbpy 4,4'-dicarboxylic acid-2,2'-bipyridine, potip 2-(4-(10H-phenothiazin-10-yl)-5-octylthiophen- 2-yl)-1H-imidazo[4,5-f][1,10] phenanthroline, and [Ru(dcbpy)(dpotip)(NCS)(2)] (JF-4, dpotip = 2-(4-(N,N-diphenylamino)-5-octylthiophen-2-yl)-1H-imidazo[4,5-f][1,10] phenanthroline) that contain electron-donating phenothiazine-based or N,N-diphenylamino-based ancillary ligands. The ruthenium dye JF-3, in which an excellent electron-donating phenothiazine is incorporated, shows superior DSC performance (9.1%; compared to 8.8% for N3). A comparison of the electron-donating phenothiazine and N, N-diphenylamino groups utilized in the molecular architecture of ruthenium dyes demonstrates that the phenothiazine group efficiently increases the molar extinction coefficient of band II and also broadens that band in the UV-vis absorption spectrum, reduces device resistance, increases electron lifetime, and enhances power-conversion efficiency. This finding not only clarifies the significance of multifunctionalized design in the molecular architecture of ruthenium dyes, but also represents an alternative route for the introduction of an excellent electron-donating group for improving the light-harvesting characteristics of ruthenium dyes as well as DSC performance.
Enhanced photovoltaic performance by synergism of light-cultivation and electronic localization for highly efficient dye-sensitized solar cells
(2009)
Yin, Jen-Fu
;
Bhattacharya, Dibyendu
;
Hsu, Ying-Chan
;
Tsai, Chen-Chuan
;
Lu, Kuang-Lieh
Two ruthenium sensitizers, [Ru(dcbpy)(opip)(NCS)(2)] (JF-1, dcbpy 4,4'-dicarboxylic acid-2,2'-bipyridine, opip = 2-(4-octylphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline) and [Ru(dcbpy)(otip)(NCS)(2)] (JF-2, otip = 2-(5-octylthiophen-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline), with unusually high power-conversion efficiency in comparison with other ruthenium complexes containing 1,10-phenanthroline-based ligands were designed. The power-conversion efficiency of JF-2 is 20% higher than that of JF-1, due to the modification of the ancillary ligand with a thiophene moiety. The origins of this device performance diversity are illustrated by photophysical properties, electrochemical data and density functional theory (DFT) studies. The greater device performance of JF-2 compared to JF-1 was caused from the broader MLCT distribution, the appropriate localization of the frontier orbitals and the stronger driving force of the charge injection and regeneration.
Structure optimization of ruthenium photosensitizers for efficient dye-sensitized solar cells - A goal toward a "bright" future
(2012-12-01)
Yin, Jen-Fu
;
Velayudham, Murugesan
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Bhattacharya, Dibyendu
;
Lin, Hong-Cheu
;
Lu, Kuang-Lieh
Research on dye-sensitized solar cells (DSC) is progressing at a rapid pace. The structural and electronic factors associated with ruthenium photosensitizers can have a significant effect on the performance of DSCs. This review emphasizes the recent developments and strategies employed in the structural design of ruthenium photosensitizers. The influence of molecular engineering on photophysical and electrochemical properties along with photovoltaic parameters and the efficiency of DSCs are also reviewed. Hence, drawing a correlation between the structure of photosensitizers, the properties and photovoltaic parameters of corresponding DSCs will be helpful in terms of optimizing new dyes for the generation of efficient solar cells. (c) 2012 Elsevier B.V. All rights reserved.
Synthesis and applications of novel acceptor-donor-acceptor organic dyes with dithienopyrrole- and fluorene-cores for dye-sensitized solar cells
(2011-01-14)
Sahu, Duryodhan
;
Padhy, Harihara
;
Patra, Dhananjaya
;
Yin, Jen-Fu
;
Hsu, Ying-Chan
Four novel symmetrical organic dyes (S1-S4) configured with acceptor-donor-acceptor (A-D-A) structures containing electron donating fluorene (S1 and S2) and N-alkyl dithieno[3,2-b:2',3'-d]pyrrole (DTP) (S3 and S4) cores terminated with two anchoring cyanoacrylic acids (as electron acceptors) were synthesized and applied to dye-sensitized solar cells (DSSCs). The DSSC device based on S2 dye showed the best photovoltaic performance among S1-S4 dyes: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 76%, a short circuit current (J(SC)) of 12.27 mA/cm(2), an open circuit voltage (V(OC)) of 0.61 V. a fill factor (FF) of 0.63, and an overall power conversion efficiency (eta) of 4.73%. Besides, the utilization of chenodoxycholic acid (CDCA) as a co-adsorbent in the DSSC device based on S3 dye showed a significant improvement in its eta value (from 3.70% to 4.31%), which is attributed to the suppression of dye aggregation on TiO(2) surface and thus to increase the J(SC) value eventually. (C) 2010 Elsevier Ltd. All rights reserved.
Toward Optimization of Oligothiophene Antennas: New Ruthenium Sensitizers with Excellent Performance for Dye-Sensitized Solar Cells
(2010-08-10)
Yin, Jen-Fu
;
Chen, Jian-Ging
;
Lu, Zong-Zhan
;
Ho, Kuo-Chuan
;
Lin, Hong-Cheu
This paper reports on the design and synthesis of three new ruthenium sensitizers, as well as the optimization of their linear or dendritic light-harvesting oligothiophene antennas to achieve superior device performance. The three new ruthenium sensitizers, [Ru(dcbpy)(obtip)(NCS)(2)] (JF-5, dcbpy = 4,4'-dicarboxylic obtip = 2-(5-octyl-(2,2'-bithiophen)-5'-yl)-1H-imidazo[4,51][1,10]-phenanthroline), [Ru(dcbpy)(ottip)(NCS)(2)] (JF-6, ottip = 2-(5-octyl-2,2',5',2 ''-terthiophen)-5 ''-yl)-1H-imidazo[4,5-f][1,10]-phenanthroline), and [Ru(dcbpy)(dottip)(NCS)(2)] (JF-7, dottip = di-(5-octylthiophen-2-ypthiophen-5-yl)-1H-imidazo[4,5-f][1,10]phenanthroline), were synthesized in a typical one-pot reaction. The ruthenium sensitizer JF-5 incorporating a linear and planar 2,2'-bithiophene antenna showed the best DSCs performance (9.5%; compared to N3, 8.8%). The difference in the performance of these sensitizers demonstrates that elongating the linear and planar light-harvesting antenna result in an enhancement in MLCT intensity, but a reduction in the quantity of dye-loading. This finding not only permitted the power-conversion efficiency in ruthenium sensitizers containing oligothiophene antennas to be optimized, but also points to a promising direction for molecule engineering in DSCs.