@article { ISI:000335947900023, title = {Disassembly of micelles in nanoscopic space to prepare concentric nanotubes with variable hydrophobic interiors}, journal = {Chemical Communications}, volume = {50}, number = {44}, year = {2014}, month = {APR}, pages = {5905-5908}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Nanotubes with variable hydrophobic interiors were prepared by disassembling anionic micelles in the inner walls of positive charge bearing conjugated polymer nanotubes.

}, issn = {1359-7345}, doi = {10.1039/c4cc00841c}, author = {Das, Chayanika and Krishnamoorthy, Kothandam} } @article { ISI:000371026700006, title = {Disassembly of micelles to impart donor and acceptor gradation to enhance organic solar cell efficiency}, journal = {Chemical Communications}, volume = {52}, number = {17}, year = {2016}, month = {JAN}, pages = {3486-3489}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

A transparent, conducting and low surface energy surface was prepared by disassembly of anionic micelles, which altered the orientation of the donor polymer and imparted gradation between the donor and acceptor. This configuration increased the solar cell device efficiency.

}, issn = {1359-7345}, doi = {10.1039/c5cc09603k}, author = {Arulkashmir, Arulraj and Krishnamoorthy, Kothandam} } @article {44453, title = {Dihedral angle control to improve the charge transport properties of conjugated polymers in organic field effect transistors}, journal = {Chemical Physics Letters}, volume = {695}, year = {2018}, month = {MAR}, pages = {51-58}, abstract = {Diketopyrrolopyrrole (DPP) and i-Indigo (i-Ind) are two monomers that are widely explored as active materials in organic field effect transistor and solar cells. These two molecules showed impressive charge carrier mobility due to better packing that are facilitated by quadrupoles. We hypothesized that the copolymers of these monomers would also exhibit high charge carrier mobility. However, we envisioned that the dihedral angle at the connecting point between the monomers will play a crucial role in packing as well as charge transport. To understand the impact of dihedral angle on charge transport, we synthesized three copolymers, wherein the DPP was sandwiched between benzenes, thiophenes and furans. The copolymer of i-Indigo and furan comprising DPP showed a band gap of 1.4 eV with a very high dihedral angle of 179 degrees. The polymer was found to pack better and the coherence length was found to be 112 angstrom. The hole carrier mobility of these polymer was found to be highest among the synthesized polymer i. e. 0.01 cm(2)/vs. The copolymer comprising benzene did not transport hole and electrons. The dihedral angle at the connecting point between i and Indigo and benzene DPP was 143 angstrom, which the packing and consequently charge transport properties. (C) 2018 Elsevier B. V. All rights reserved.}, doi = {10.1016/j.cplett.2018.01.052}, author = {Dharmapurikar, Satej S. and Chithiravel, Sundaresan and Mane, Manoj V. and Deshmukh, Gunvant and Krishnamoorthy, Kothandam} } @article {48299, title = {D-A-D-based unsymmetrical thiosquaraine dye for the dye-sensitized solar cells(dagger)}, journal = {Photochemistry and Photobiology}, volume = {99}, year = {2023}, month = {MAR}, pages = {529-537}, type = {Article}, abstract = {

In dye-sensitized solar cell, modulating the electronic properties of the sensitizer by varying the donor, pi-spacer, acceptor and anchoring groups help optimizing the structure of the dye for better device performance. Here, a donor-acceptor-donor-based unsymmetrical thiosquaraine sensitizer (SQ5S) has been designed and synthesized. Photophysical, electrochemical, theoretical and photovoltaic characterizations of SQ5S dye have been compared with its oxygen analog, SQ5. The incorporation of the sulfur atom in the acceptor unit of SQ5S dye showed an intense peak at 688 nm, which was 38 nm of red-shifted and showed the panchromatic light harvesting response with the onset of 850 nm compared with SQ5 dye. The LUMO and HOMO energy levels are well aligned with the conduction band of TiO2 and the redox potential of electrolyte for the charge injection and the dye-regeneration processes, respectively. Photovoltaic efficiency of 1.51\% (V-OC 610 mV, J(SC) 3.07 mA cm(-2), ff 81\%) has been achieved for SQ5S dye, whereas SQ5 showed the device performance of 5.43\% (V-OC 723 mV, J(SC) 9.3 mA cm(-2), ff 80\%). The decreased device performance for the dye SQ5S has been attributed to the favorable intersystem crossing process associated with the photoexcited SQ5S that reduces the driving force for the charge injection process.

}, issn = {0031-8655}, doi = {10.1111/php.13769}, author = {Jadhav, Avinash P. and Singh, Ambarish Kumar and Maibam, Ashakiran and Krishnamurty, Sailaja and Krishnamoorthy, Kothandam and Nithyanandhan, Jayaraj} }