Marappan Velusamy

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Two isomeric compounds (1 and 2) containing a dibenzo[f,h]thieno[3,4-b]quinoxaline core and two peripheral arylamines were synthesized. Solution-processed bulk heterojunction (BHJ) solar cells based on these sensitizers and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) are reported. The cell fabricated from 1/67 wt % of PCBM exhibited a high power(More)
Versatile dyes based on benzothiadiazole and benzoselenadiazole chromophores have been developed that perform efficiently in dye-sensitized solar cells. Power conversion efficiency of 3.77% is realized for a dye in which charge recombination is probably hindered by the nonplanar charge-separated structure.
Heteroleptic cyclometalated iridium(III) complexes featuring lepidine-based ligands and acetyl acetone auxiliary ligand are synthesized. Multiple lowest energy absorption bands are observed for these complexes indicating substantial mixing of the singlet and triplet levels. All the complexes emit orange or red color in dichloromethane solutions with(More)
A facile one step method for periodic nanostructuring of organic solar cells is presented. The nanostructured metal-organic interface delivers combined enhanced light trapping and improved charge extraction leading to up to a 10% increase in power conversion efficiency of already optimized planar devices.
Fullerene derivatives are commonly used as electron acceptors in combination with (macro)molecular electron donors in bulk heterojunction (BHJ) organic photovoltaic (OPV) devices. Understanding the BHJ structure at different electron donor/acceptor ratios is critical to the continued improvement and development of OPVs. The high neutron scattering length(More)
A series of donor-pi-acceptor-type organic dyes based on 1-alkyl-1H-imidazole spacers 1-5 have been developed and characterized. The two electron donors are at positions 4 and 5 of the imidazole, while the electron-accepting cyanoacrylic acid is incorporated at position 2 by a spacer-containing heteroaromatic rings, such as thiophene and thiazole. Detailed(More)
We have used steady-state and time-resolved neutron reflectometry to study the diffusion of fullerene derivatives into the narrow optical gap polymer poly[N-9″-hepta-decanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) to explore the sequential processing of the donor and acceptor for the preparation of efficient organic(More)
New CN donor ligands incorporating pyridine or benzoimidazole N donors and a sterically hindered cyclometalating aromatic core featuring a polyphenylenephenyl, fluoranthene, or triphenylene segment are prepared and successfully converted into heteroleptic iridium(III) cyclometalated complexes with acetylacetone auxiliary ligands. The X-ray structure of the(More)
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