@article{kirk_shultz_marri_est_2024, title={Photoinduced Magnetic Exchange-Jump Promotes Ground State Biradical Electron Spin Polarization}, volume={3}, ISSN={["1520-5126"]}, url={https://doi.org/10.1021/jacs.4c00930}, DOI={10.1021/jacs.4c00930}, abstractNote={Photoinduced electron spin polarization (ESP) is reported in the electronic ground states of three Pt(II) complexes comprised of two S = 1/2 nitronyl nitroxide (NN) radicals attached through different length para-phenylethynyl bridges to the 3,6 positions of a catecholate (CAT, donor) and 4,4'-di-tert-butyl-2,2'-bipyridine (bpy, acceptor). Complexes 1-3 have from 17 to 41 bonds separating NN radicals and display cw-EPR spectra consistent with |JNN-NN| ≫ |aN|, |JNN-NN| ≥ |aN|, and |JNN-NN| < |aN|, respectively, where JNN-NN is the magnetic exchange coupling between NN radicals in the electronic ground state, and aN is the isotropic 14N hyperfine coupling constant. Light-induced transient EPR spectra characterized as enhanced ground-state absorption were observed for all three complexes using 532 nm pulsed laser excitation into the ligand-to-ligand charge transfer (LL'CT) band of the (CAT)Pt(bpy) chromophore. The magnitude of the observed ESP increases in the order 1 < 2 < 3 and is inversely correlated with the magnitude of ground-state JNN-NN. In addition to the experimental observation of net absorptive polarization in 1-3, light excitation also produces multiplet polarization in 2. Since the weak dipolar coupling leads to a strong spectral overlap of the absorptive and emissive components, the multiplet polarization is not observed in 1 and 3 and is very weak in 2. The ability to spin-polarize multiple radical spins with a single photon is anticipated to advance new photoinduced multi qubit/qudit ESP protocols for quantum information science applications.}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Kirk, Martin L. and Shultz, David A. and Marri, Anil Reddy and Est, Art}, year={2024}, month={Mar} }
 @article{kirk_shultz_hewitt_marri_est_2023, title={Competitive reversed quartet mechanisms for photogenerated ground state electron spin polarization}, volume={8}, ISSN={["2041-6539"]}, DOI={10.1039/d3sc03049}, journal={CHEMICAL SCIENCE}, author={Kirk, Martin L. and Shultz, David A. and Hewitt, Patrick and Marri, Anil Reddy and Est, Art}, year={2023}, month={Aug} }
 @article{kirk_shultz_hewitt_marri_est_2023, title={Competitive reversed quartet mechanisms for photogenerated ground state electron spin polarization}, volume={14}, ISSN={["2041-6539"]}, url={https://doi.org/10.1039/D3SC03049K}, DOI={10.1039/d3sc03049k}, abstractNote={Different excited state equilibration pathways yield ground-state electron spin polarization of radical-elaborated platinum(ii) complexes. The equilibration pathways are controlled through designed molecular conformation.}, number={36}, journal={CHEMICAL SCIENCE}, author={Kirk, Martin L. and Shultz, David A. and Hewitt, Patrick and Marri, Anil Reddy and Est, Art}, year={2023}, month={Sep}, pages={9689–9695} }
 @article{reddy-marri_marchini_cabanes_argazzi_pastore_caramori_gros_2023, title={Panchromatic light harvesting and record power conversion efficiency for carboxylic/cyanoacrylic Fe(<scp>ii</scp>) NHC co-sensitized FeSSCs}, volume={14}, ISSN={2041-6520 2041-6539}, url={http://dx.doi.org/10.1039/D2SC05971A}, DOI={10.1039/D2SC05971A}, abstractNote={The co-sensitization of TiO2 by using a combination of carboxylic and thienylcyanoacrylic (ThCA)–Fe(ii) pyridyl-NHC sensitizers produced a panchromatic absorption and the best photocurrent and efficiency ever reported for an FeSSC.}, number={16}, journal={Chemical Science}, publisher={Royal Society of Chemistry (RSC)}, author={Reddy-Marri, Anil and Marchini, Edoardo and Cabanes, Valentin Diez and Argazzi, Roberto and Pastore, Mariachiara and Caramori, Stefano and Gros, Philippe C.}, year={2023}, pages={4288–4301} }
 @article{marri_marekha_penfold_haacke_gros_2023, title={Towards panchromatic Fe(<scp>ii</scp>) NHC sensitizers <i>via</i> HOMO inversion}, volume={10}, ISSN={2052-1553}, url={http://dx.doi.org/10.1039/D2QI01903E}, DOI={10.1039/D2QI01903E}, abstractNote={Fused polythiophenes attached to Fe(ii)NHC complexes induced a mixing of the t2gand π HOMO orbitals promoting 80 nm red-shift of the MLCT transition, 3 fold increase of the molar extinction coefficient and3MLCT excited state lifetime up to 18 ps.}, number={1}, journal={Inorganic Chemistry Frontiers}, publisher={Royal Society of Chemistry (RSC)}, author={Marri, Anil Reddy and Marekha, Bogdan and Penfold, Thomas and Haacke, Stefan and Gros, Philippe C.}, year={2023}, pages={118–126} }
 @article{delcroix_reddy marri_parant_gros_bouché_2023, title={Water‐Soluble Fe(II) Complexes for Theranostic Application: Synthesis, Photoacoustic Imaging, and Photothermal Conversion}, volume={5}, ISSN={1434-1948 1099-0682}, url={http://dx.doi.org/10.1002/ejic.202300138}, DOI={10.1002/ejic.202300138}, abstractNote={Abstract}, journal={European Journal of Inorganic Chemistry}, publisher={Wiley}, author={Delcroix, Maeva and Reddy Marri, Anil and Parant, Stéphane and Gros, Philippe C. and Bouché, Mathilde}, year={2023}, month={May} }
 @article{marri_flint_gibson_fielden_2022, title={Pyridyl anchored indolium dyes for the p-type dye sensitized solar cell}, volume={202}, url={http://dx.doi.org/10.1016/j.dyepig.2022.110244}, DOI={10.1016/j.dyepig.2022.110244}, abstractNote={Three new thiophenyl bridged triarylamine-donor based dyes with pyridyl anchoring groups and indolium acceptors have been synthesized and studied as sensitizers for the p-type dye-sensitized solar cell (p-DSSC). Compared to known dicyano and pyridinium dyes with the same triarylamine cores, these new sensitizers have broadened and red-shifted UV–vis absorption spectra, with high extinction coefficients and absorption extending beyond 700 nm. TD-DFT calculations on the indolium family indicate that these dyes combine strong donor acceptor communication, with a high degree of charge separation in the excited state – an ideal combination for sensitizer dyes. The phenylpyridyl anchored bis-indolium gives the highest power conversion efficiency (0.097%) through a short circuit photocurrent (JSC) of 3.04 mA cm−2, open circuit voltage (VOC) of 97 mV and fill factor of 36%. This exceeds the performance of the P1 reference dye in this study, and represents the best performance so far for a cationic, pyridine anchored p-DSSC dye.}, journal={Dyes and Pigments}, publisher={Elsevier BV}, author={Marri, Anil Reddy and Flint, Heather and Gibson, Elizabeth A. and Fielden, John}, year={2022}, month={Jun}, pages={110244} }
 @article{kirk_shultz_marri_hewitt_van der est_2022, title={Single-Photon-Induced Electron Spin Polarization of Two Exchange-Coupled Stable Radicals}, volume={144}, ISSN={0002-7863 1520-5126}, url={http://dx.doi.org/10.1021/jacs.2c09680}, DOI={10.1021/jacs.2c09680}, abstractNote={Transient electron paramagnetic resonance spectroscopy has been used to probe photoinduced electron spin polarization of a stable exchange-coupled organic biradical in a Pt(II) complex comprising 4,4'-di-tert-butyl-2,2'-bipyridine (bpy) and 3,6-bis(ethynyl-para-phenyl-nitronyl nitroxide)-o-catecholate (CAT(o-C≡C-Ph-NN)2). Photoexcitation results in four unpaired spins in excited states of this complex, with spins being localized on each of the two radicals, CAT•+ and bpy•-. The four spins are all exchange-coupled in these excited states, and an off-diagonal matrix element in the CAT•+-NN exchange allows for exchange-enhanced intersystem crossing to the 3T1a state, which possesses (bpy•-)Pt(CAT•+) chromophoric triplet character. Fast mixing between this 3T1a state and thermally accessible excited LL'CT state(s) followed by fast relaxation provides spin polarization of the exchange-coupled NN radicals in the 3S0 ground state of the complex. Our results demonstrate that well-defined quantum states of a ground-state biradical can be initialized with single-photon excitation and have the potential for further spin manipulation directed toward quantum information science applications.}, number={46}, journal={Journal of the American Chemical Society}, publisher={American Chemical Society (ACS)}, author={Kirk, Martin L. and Shultz, David A. and Marri, Anil Reddy and Hewitt, Patrick and van der Est, Art}, year={2022}, month={Nov}, pages={21005–21009} }
 @article{carrillo_francés-monerris_marri_cebrián_gros_2022, title={Substituent-Induced Control of <i>fac</i>/<i>mer</i> Isomerism in Azine-NHC Fe(II) Complexes}, volume={2}, ISSN={2694-247X 2694-247X}, url={http://dx.doi.org/10.1021/acsorginorgau.2c00038}, DOI={10.1021/acsorginorgau.2c00038}, abstractNote={The stereoselective synthesis of geometrical iron(II) complexes bearing azine-NHC ligands is described. Facial and meridional selectivity is achieved as a function of the steric demand of the azine unit, with no remarkable influence of the carbene nature. More specifically, meridional complexes are obtained upon selecting bulky 5-mesityl-substituted pyridyl coordinating units. Unexpectedly, increase of the steric hindrance in the α position with respect to the N coordinating atom results in an exclusive facial configuration, which is in stark contrast to the meridional selectivity induced by other reported α-substituted bidentate ligands. Investigation of the structure and the optical and electrochemical properties of the here-described complexes has revealed the non-negligible effect of the fac/mer ligand configuration around the metal center.}, number={6}, journal={ACS Organic & Inorganic Au}, publisher={American Chemical Society (ACS)}, author={Carrillo, Ulises and Francés-Monerris, Antonio and Marri, Anil Reddy and Cebrián, Cristina and Gros, Philippe C.}, year={2022}, month={Sep}, pages={525–536} }
 @article{marri_marchini_cabanes_argazzi_pastore_caramori_bignozzi_gros_2021, title={A Series of Iron(II)‐NHC Sensitizers with Remarkable Power Conversion Efficiency in Photoelectrochemical Cells**}, volume={27}, url={https://doi.org/10.1002/chem.202103178}, DOI={10.1002/chem.202103178}, abstractNote={Abstract}, number={65}, journal={Chemistry – A European Journal}, publisher={Wiley}, author={Marri, Anil Reddy and Marchini, Edoardo and Cabanes, Valentin Diez and Argazzi, Roberto and Pastore, Mariachiara and Caramori, Stefano and Bignozzi, Carlo Alberto and Gros, Philippe C.}, year={2021}, month={Nov}, pages={16260–16269} }
 @article{marri_marchini_cabanes_argazzi_pastore_caramori_gros_2021, title={Record power conversion efficiencies for iron(ii)-NHC-sensitized DSSCs from rational molecular engineering and electrolyte optimization}, volume={9}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85100871609&partnerID=MN8TOARS}, DOI={10.1039/d0ta10841c}, abstractNote={The highest efficiency ever reported for an iron-sensitized solar cell has been obtained using a Fe(ii) pyridylNHC-carboxylic heteroleptic complex. Mg2+ cations and NBu4I in the electrolyte, substantially boosted the photocurrent.}, number={6}, journal={Journal of Materials Chemistry A}, publisher={Royal Society of Chemistry (RSC)}, author={Marri, Anil Reddy and Marchini, Edoardo and Cabanes, Valentin Diez and Argazzi, Roberto and Pastore, Mariachiara and Caramori, Stefano and Gros, Philippe C.}, year={2021}, pages={3540–3554} }
 @article{hainer_alagna_reddy marri_penfold_gros_haacke_buckup_2021, title={Vibrational Coherence Spectroscopy Identifies Ultrafast Branching in an Iron(II) Sensitizer}, volume={12}, ISSN={1948-7185 1948-7185}, url={http://dx.doi.org/10.1021/acs.jpclett.1c01580}, DOI={10.1021/acs.jpclett.1c01580}, abstractNote={The introduction of N-heterocyclic carbene ligands has greatly increased the lifetimes of metal-to-ligand charge transfer states (MLCT) in iron(II) complexes, making them promising candidates for photocatalytic applications. However, the spectrally elusive triplet metal-centered state (3MC) has been suggested to play a decisive role in the relaxation of the MLCT manifold to the ground state, shortening their lifetimes and consequently limiting the application potential. In this work, time-resolved vibrational spectroscopy and quantum chemical calculations are applied to shed light on the 3MCs' involvement in the deactivation of the MLCT manifold of an iron(II) sensitizer. Two distinct symmetric Fe-L breathing vibrations at frequencies below 150 cm-1 are assigned to the 3MC and 3MLCT states by quantum chemical calculations. On the basis of this assignment, an ultrafast branching directly after excitation forms not only the long-lived 3MLCT but also the 3MC as an additional loss channel.}, number={35}, journal={The Journal of Physical Chemistry Letters}, publisher={American Chemical Society (ACS)}, author={Hainer, F. and Alagna, N. and Reddy Marri, A. and Penfold, T. J. and Gros, P. C. and Haacke, S. and Buckup, T.}, year={2021}, month={Sep}, pages={8560–8565} }
 @article{marri_black_mallows_gibson_fielden_2019, title={Pyridinium p-DSSC dyes: An old acceptor learns new tricks}, volume={165}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85062805204&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2019.02.044}, abstractNote={A family of six (five new) thiophenyl bridged triarylamine-donor based dyes with pyridine anchoring groups have been synthesized and studied as sensitizers for the p-type dye-sensitized solar cell (p-DSSC). They comprise bis-dicyano acceptor systems with a single pyridyl binder incorporated directly into the triarylamine (1), or separated by a phenyl group (2); a mono-dicyano with two phenyl pyridine binders (3); and respective homologues 4 to 6 with pyridinium acceptors. In all cases, compared to their dicyano counterparts, the pyridinium based dyes have higher extinction coefficients and smaller HOMO-LUMO gaps that give broader spectrum absorption. Thus, despite lower dye uptake, devices based on pyridiniums 4 and 6 have identical power conversion efficiencies (η) to the equivalent dicyano systems 1 and 3. However, the best performing device (η = 0.06%) is based on the known bis-acceptor dicyano system 2, as the large size and double positive charge of 5 leads to a substantial disadvantage in loading on NiO. Absorbed-photon-to-current efficiencies for 5 are competitive with or higher than those of 2, implying a better per dye performance consistent with the absorption profile, and DFT calculations suggesting better charge separation. Thus, pyridiniums may provide a new, and easily accessible high performance acceptor for p-DSSC dyes, but are likely better paired with anionic binding groups such as carboxylates.}, journal={Dyes and Pigments}, publisher={Elsevier BV}, author={Marri, A.R. and Black, F.A. and Mallows, J. and Gibson, E.A. and Fielden, J.}, year={2019}, pages={508–517} }
 @article{el moll_black_wood_al-yasari_reddy marri_sazanovich_gibson_fielden_2017, title={Increasing p-type dye sensitised solar cell photovoltages using polyoxometalates}, volume={19}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85026386682&partnerID=MN8TOARS}, DOI={10.1039/c7cp01558e}, abstractNote={Lindqvist polyoxometalates increase p-DSSC VOC by up to 140%, through a combination of retarded recombination, valence band shift and screening.}, number={29}, journal={Physical Chemistry Chemical Physics}, publisher={Royal Society of Chemistry (RSC)}, author={El Moll, H. and Black, F.A. and Wood, C.J. and Al-Yasari, A. and Reddy Marri, A. and Sazanovich, I.V. and Gibson, E.A. and Fielden, J.}, year={2017}, pages={18831–18835} }
 @article{marri_cho_lee_kim_huy_hwang_baek_2017, title={Synthesis, characterization and photophysical behavior of heteroleptic ruthenium-complexed ladder-like structured polysilsesquioxanes}, volume={25}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85028063802&partnerID=MN8TOARS}, DOI={10.1007/s13233-017-5110-0}, number={6}, journal={Macromolecular Research}, publisher={Springer Science and Business Media LLC}, author={Marri, A.R. and Cho, K.Y. and Lee, A.S. and Kim, H.-J. and Huy, D.X. and Hwang, S.S. and Baek, K.-Y.}, year={2017}, pages={591–598} }
 @article{reddy_kumar_ashok_sharma_sharma_chandrasekharam_2016, title={Hetero aromatic donors as effective terminal groups for DPP based organic solar cells}, volume={6}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84957007345&partnerID=MN8TOARS}, DOI={10.1039/c5ra24610e}, abstractNote={Phenoxazine and carbazole end-capped donor–acceptor–donor (D–A–D) based small moleculesCSDPP5–CSDPP8have been synthesized. The device withCSDPP6:PC71BM as active layer exhibited a PCE of 4.69%.}, number={11}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Reddy, M.A. and Kumar, C.P. and Ashok, A. and Sharma, A. and Sharma, G.D. and Chandrasekharam, M.}, year={2016}, pages={9023–9036} }
 @article{vinayak_reddy_chiranjeevi_chandrashekharam_poornachandra_ganesh kumar_2016, title={Iron-catalyzed cyclization of aminothiols: An easy access to benzothiazoles and evaluation of their antimicrobial and anti-biofilm activities}, volume={55B}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85009289882&partnerID=MN8TOARS}, number={4}, journal={Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry}, author={Vinayak, B. and Reddy, M.A. and Chiranjeevi, B. and Chandrashekharam, M. and Poornachandra, Y. and Ganesh Kumar, C.}, year={2016}, pages={461–470} }
 @article{gupta_zhang_marotta_reddy_singh_islam_han_de angelis_chandrasekharam_pastore_2015, title={Effect of the anchoring group in the performance of carbazole-phenothiazine dyads for dye-sensitized solar cells}, volume={113}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84924293051&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2014.09.032}, abstractNote={A combined experimental and theoretical study is carried out on two novel carbazole-phenothiazine dyadic dyes bearing the simple carboxylic acid and the more rarely investigated malonic acid as anchoring group. An improvement of the photovoltaic performances is observed when the malonic acid is employed in place of the carboxylic acid, even if the highest efficiencies for this family of organic dyes were recorded with the use of the cyanoacrylic and rhodanine-3-aceti acid as anchoring units. The low photocurrents measured in the case of the carboxylic anchoring are rationalized on the basis of the computational modelling of the isolated dye in solution as well as the investigation of the electronic structure of extended dye-sensitized TiO2 models. The theoretical calculations suggest that the low short current densities might arise from the unfavourable interplay of the dye's optical properties (blue shift of the absorption spectrum) and of the energy alignment between the dye's LUMO and the semiconductor conduction band edge, possibly causing an inefficient electron injection process.}, journal={Dyes and Pigments}, publisher={Elsevier BV}, author={Gupta, K.S.V. and Zhang, J. and Marotta, G. and Reddy, M.A. and Singh, S.P. and Islam, A. and Han, L. and De Angelis, F. and Chandrasekharam, M. and Pastore, M.}, year={2015}, pages={536–545} }
 @article{sharma_anil reddy_ramana_chandrasekharam_2014, title={A novel carbazole-phenothiazine dyad small molecule as a non-fullerene electron acceptor for polymer bulk heterojunction solar cells}, volume={4}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84905727400&partnerID=MN8TOARS}, DOI={10.1039/c4ra05584e}, abstractNote={A small organic moleculeCSORG5developed as non fullerene acceptor for BHJ solar cells. The device based on P3HT : CSORG5(1 : 1) spin coated from DIO/THF showed high PCE 2.80% compared to spin coated from THF. The PCE has been further increased to 4.16%, when the TiO2film was inserted between the active layer and Al electrode.}, number={63}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Sharma, G.D. and Anil Reddy, M. and Ramana, D.V. and Chandrasekharam, M.}, year={2014}, pages={33279–33285} }
 @article{lobello_wu_reddy_marotta_grätzel_nazeeruddin_chi_chandrasekharam_vitillaro_de angelis_2014, title={Engineering of Ru(ii) dyes for interfacial and light-harvesting optimization}, volume={43}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84962419504&partnerID=MN8TOARS}, DOI={10.1039/c3dt53272k}, abstractNote={A new ruthenium dye sensitizer based on a dissymmetric bipyridine ligand has been synthesized and employed in dye-sensitized solar cells for enhanced interfacial and optical properties.}, number={7}, journal={Dalton Transactions}, publisher={Royal Society of Chemistry (RSC)}, author={Lobello, M.G. and Wu, K.-L. and Reddy, M.A. and Marotta, G. and Grätzel, M. and Nazeeruddin, M.K. and Chi, Y. and Chandrasekharam, M. and Vitillaro, G. and De Angelis, F.}, year={2014}, pages={2726–2732} }
 @article{anil reddy_vinayak_suresh_niveditha_bhanuprakash_prakash singh_islam_han_chandrasekharam_2014, title={Highly conjugated electron rich thiophene antennas on phenothiazine and phenoxazine-based sensitizers for dye sensitized solar cells}, volume={195}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84903977896&partnerID=MN8TOARS}, DOI={10.1016/j.synthmet.2014.06.009}, abstractNote={Four new organic dyes, coded as CSORG6, CSORG7, CSORG8 and CSORG9, comprising electron rich thiophene derivatives as antennas and cyanoacrylic acid as acceptor, bridged by phenothiazine or phenoxazine were designed and synthesized for dye-sensitized solar cells applications. They were fully characterized with their photophysical, electrochemical properties, density functional theory (DFT), time dependent density DFT (TDDFT) and the light-harvesting properties of the new sensitizers were evaluated with nanocrystalline TiO2-based devices. Among the four diheteroanthracene based dyes, phenoxazine (CSORG7 and CSORG9) based devices afforded the best photovoltaic performance (η) of 6% under standard AM 1.5G solar irradiation, whereas, N719 showed (η) 6.4% under the similar fabrication and evolution conditions.}, journal={Synthetic Metals}, publisher={Elsevier BV}, author={Anil Reddy, M. and Vinayak, B. and Suresh, T. and Niveditha, S. and Bhanuprakash, K. and Prakash Singh, S. and Islam, A. and Han, L. and Chandrasekharam, M.}, year={2014}, pages={208–216} }
 @article{sharma_reddy_ganesh_singh_chandrasekharam_2014, title={Indole and triisopropyl phenyl as capping units for a diketopyrrolopyrrole (DPP) acceptor central unit: An efficient D-A-D type small molecule for organic solar cells}, volume={4}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84889585654&partnerID=MN8TOARS}, DOI={10.1039/c3ra44926b}, abstractNote={Two simple D–A–D structured small molecules based on diketopyrrolopyrrole as central acceptor unit and different terminal units (indole and 2,4,6-triisopropylphenyl for CSDPP1 and CSDPP3 respectively) with broad absorption band and suitable energy levels were synthesized. The new DPP molecules are fully characterized and their photovoltaic properties were investigated using them as donor components along with PC70BM as acceptor in the bulk heterojunction (BHJ) active layer. The organic BHJ solar cells based on CSDPP1:PC70BM and CSDPP3:PC70BM (1:1 D–A ratio) cast from chloroform solvent showed moderate power conversion efficiency of about 3.26% and 2.42%, respectively. The higher power conversion efficiency (PCE) of organic solar cells based on CSDPP1 as donor as compared to CSDPP3 has been attributed to the higher hole mobility and absorption coefficient and low optical band gap of CSDPP1. The PCE of the thermally annealed device based on CSDPP1:PC70BM has been improved up to 4.96% attributed to the better film morphology and increased absorption of the BHJ active layer. We attribute the increase in absorption intensity upon thermal annealing to the stronger electrical polarization in the BHJ active layer resulting from morphological changes i.e. crystallinity and molecular aggregation. Finally, the capacitance–voltage measurements indicates that the increasing local electrical polarizations upon thermal annealing can lead to an enhancement of the charge generation from the excitons at donor–acceptor interfaces and their transportation to the respective electrodes in the BHJ device, leading to better short circuit photocurrents and fill factors.}, number={2}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Sharma, G.D. and Reddy, M.A. and Ganesh, K. and Singh, S.P. and Chandrasekharam, M.}, year={2014}, pages={732–742} }
 @article{chandrasekharam_reddy_ganesh_sharma_singh_rao_2014, title={Synthesis and photovoltaic properties of D-A-D type small molecules containing diketopyrrolopyrrole (DPP) acceptor central unit with different donor terminal units}, volume={15}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84903730708&partnerID=MN8TOARS}, DOI={10.1016/j.orgel.2014.05.033}, abstractNote={Abstract Two D–A–D small molecules TDPP (FP)2 and TDPP (BuP)2 coded as CSDPP2 and CSDPP4 respectively were synthesized having same diketopyrrolopyrrole (DPP) as core acceptor and difluoro-phenyl (FP) and dibutyloxy phenyl (BuP) as different end donor units with broad absorption and suitable energy levels. We have used these small molecules as donor components along with the PC70BM as electron acceptor for the preparation of bulk heterojunction (BHJ) active layer in small molecule (SM) organic photovoltaics (OPV) test cells. The optimal power conversion efficiencies obtained with CSDPP2 and CSDPP4 are 2.26% and 3.23% when the BHJ active layer was cast from CF solvent. The PCE has been further enhanced up to 3.03% and 4.65% for CSDPP2 and CSDPP4 when the BHJ active layer was cast from CN/CF solvent. The enhancement in PCE has been explained in terms of change in crystallinity and nanoscale morphology and more balanced charge transport resulting from increased hole mobility.}, number={9}, journal={Organic Electronics}, publisher={Elsevier BV}, author={Chandrasekharam, M. and Reddy, M.A. and Ganesh, K. and Sharma, G.D. and Singh, S.P. and Rao, J.L.}, year={2014}, pages={2116–2125} }
 @article{marotta_reddy_singh_islam_han_de angelis_pastore_chandrasekharam_2013, title={Novel carbazole-phenothiazine dyads for dye-sensitized solar cells: A combined experimental and theoretical study}, volume={5}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84885442171&partnerID=MN8TOARS}, DOI={10.1021/am402675q}, abstractNote={We report a joint experimental and computational work on new organic donor-acceptor dye sensitizers in which a carbazole (CZ) and a phenothiazine (PTZ) units are linked together by an alkyl C6H13, while two different anchoring groups are employed: the cyanoacrylic acid (CS1A, CSORG1) and the rhodanine-3-acetic acid (CS4A, CSORG4). The CZ moiety has multiple roles of (i) acting as an extra-electron donor portion, providing more electron density on the PTZ; (ii) suppressing the back-electron transfer from TiO2 to the electrolyte by forming a compact insulating dye layer; (iii) modulating dye aggregation on the semiconductor surface; and (iv) acting as an antenna, collecting photons and, through long-range energy transfer, redirecting the captured energy to the dye sensitizer. We show that the introduction of the CZ donor remarkably enhances the photovoltaic performances of the rhodanine-based dye, compared to the corresponding simple PTZ dye, with more than a two-fold increase in the overall efficiencies, while it does not bring beneficial effects in the case of the cyanoacrylic-based sensitizer. Based on quantum mechanical calculations and experimental measurements, we show that, in addition to a favored long-range energy transfer, which increases the light absorption in the blue region of the spectrum, the presence of the CZ unit in the CSORG4 dye effectively induces a beneficial aggregation pattern on the semiconductor surface, yielding a broadened and red-shifted light absorption, accounting for the two-fold increase in the generated photocurrent.}, number={19}, journal={ACS Applied Materials and Interfaces}, publisher={American Chemical Society (ACS)}, author={Marotta, G. and Reddy, M.A. and Singh, S.P. and Islam, A. and Han, L. and De Angelis, F. and Pastore, M. and Chandrasekharam, M.}, year={2013}, pages={9635–9647} }
 @article{agrawal_pastore_marotta_reddy_chandrasekharam_de angelis_2013, title={Optical properties and aggregation of phenothiazine-based dye-sensitizers for solar cells applications: A combined experimental and computational investigation}, volume={117}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84878072118&partnerID=MN8TOARS}, DOI={10.1021/jp4026305}, abstractNote={Combining computational modeling and experimental optical analyses, we investigate two prototypical phenothiazine-based organic solar cell sensitizers with the aim to understand the individual effects of solvation and aggregation on the dyes optical properties. Dye solvation and aggregation play a crucial role in determining the photoelectrochemical properties of these systems and the interplay of these two factors can lead to a misinterpretation of the underlying phenomenology due to their similar spectroscopic signals. In particular, upon adsorption of the dye onto the metal oxide surface, the dye UV–vis absorption spectrum may attain either a blue or a red shift compared to the dye in solution, which can either be originated from aggregation of surface-adsorbed dye and solvatochromism in the initial dye solution. Understanding the origin of these spectral changes along with their possible effect on charge-transfer properties is important for the further improvement of dye-sensitized solar cells. Based ...}, number={19}, journal={Journal of Physical Chemistry C}, publisher={American Chemical Society (ACS)}, author={Agrawal, S. and Pastore, M. and Marotta, G. and Reddy, M.A. and Chandrasekharam, M. and De Angelis, F.}, year={2013}, pages={9613–9622} }
 @article{chandrasekharam_reddy_singh_priyanka_bhanuprakash_kantam_islam_han_2012, title={One bipyridine and triple advantages: tailoring ancillary ligands in ruthenium complexes for efficient sensitization in dye solar cells}, volume={22}, url={http://dx.doi.org/10.1039/c2jm34558g}, DOI={10.1039/c2jm34558g}, abstractNote={Four new ruthenium bipyridyl complexes denoted as MC103–MC106, with novel unsymmetrical bipyridines as ancillary ligands have been successfully synthesized as efficient sensitizers for application in dye-sensitized solar cells (DSC). The spectral, electrochemical and photovoltaic properties of the new sensitizers have been investigated. Alkyl thiophene/alkyl bithiophene and trialkyl phenyl as substituents on ancillary ligands improved the spectral properties and hence better efficiencies of DSCs are achieved. The higher efficiencies of the new sensitizers obtained are 9.56%, 9.58%, 8.34% and 8.32%, respectively, compared to 7.2% for the standard N719 sensitizer fabricated and evaluated under similar conditions.}, number={36}, journal={Journal of Materials Chemistry}, publisher={Royal Society of Chemistry (RSC)}, author={Chandrasekharam, M. and Reddy, M. Anil and Singh, Surya P. and Priyanka, B. and Bhanuprakash, K. and Kantam, M. Lakshmi and Islam, A. and Han, L.}, year={2012}, pages={18757} }
 @article{chandrasekharam_srinivasarao_suresh_reddy_raghavender_rajkumar_srinivasu_reddy_2011, title={High spectral response heteroleptic ruthenium (II) complexes as sensitizers for dye sensitized solar cells}, volume={123}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79951785883&partnerID=MN8TOARS}, DOI={10.1007/s12039-011-0066-7}, abstractNote={Heteroleptic ruthenium(II) bipyridyl complex, cis-Ru(II)(4,4’-bis(4-tert-butylstyryl)-2,2’-bipyridyl) (4,4’-dicarboxy-2,2’-bipyridyl) (NCS2) (H112) was synthesized and characterized by 1H-NMR, MASS, Spectrofluorometer and UV-Vis spectroscopes. The photo-voltaic performance of the sensitizer was evaluated in Dye Sensitized Solar Cell (DSSC) under irradiation of AM 1·5G solar light and the photovoltaic characteristics were compared with those of reference cells of HRS1 and N719 fabricated under comparable conditions. Compared to N719, H112 sensitizer showed enhanced molar extinction coefficient and relatively better monochromatic incident photon-to-current conversion efficiency (IPCE) across the spectral range of 400 to 800nm with solar energy-to-electrical conversion efficiency (η) of 2·43% [open circuit photovoltage (V OC)=0·631V, short-circuit photocurrent density (J SC)=8·96mA/cm2, fill factor (ff)=0·430], while η values of 2·51% (V OC=0·651V, J SC=9·41 mA/cm2, ff=0·410) and 2·74% (V OC=0·705V, J SC=8·62mA/cm2, ff=0·455) were obtained for HRS1 and N719 sensitized solar cells respectively. The introduction of 4,4’-bis(4-tert-butylstyryl) moieties on one of the bipyridine moieties of N719 complex shows higher light absorption abilities, IPCE and J SC.}, number={1}, journal={Journal of Chemical Sciences}, author={Chandrasekharam, M. and Srinivasarao, C. and Suresh, T. and Reddy, M.A. and Raghavender, M. and Rajkumar, G. and Srinivasu, M. and Reddy, P.Y.}, year={2011}, pages={37–46} }
 @article{chandrasekharam_rajkumar_srinivasa rao_suresh_anil reddy_yella reddy_soujanya_takeru_jun-ho_nazeeruddin_et al._2011, title={Polypyridyl Ru(II)-sensitizers with extended π-system enhances the performance of dye sensitized solar cells}, volume={161}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79957939423&partnerID=MN8TOARS}, DOI={10.1016/j.synthmet.2011.03.022}, abstractNote={New polypyridyl ruthenium(II) complexes “cis-Ru(4,4′-dimesityl-2,2′-bipyridine) (Ln) (NCS)2 H102” and “cis-Ru(4,4′-bis(2,3,6-tri-isopropylphenyl)-2,2′-bipyridine) (Ln) (NCS)2 H105”, where Ln = 4,4′-dicarboxylic acid-2,2′-bipyridine; were synthesized and successfully applied to sensitization of nano-crystalline TiO2 based solar cells (DSSCs). The DSSCs of H102 and H105 fabricated from 0.16 cm2 TiO2 electrodes exhibited broader comparable photocurrent action spectra with almost identical solar-to-electrical energy conversion efficiency (η) as compared to N719 sensitizer. The incident photon-to-current conversion efficiency (IPCE) values of 98% and 95% were obtained for H102 and H105 sensitizers respectively. Under 1 sun condition, η-values of 8.39% (short-circuit photocurrent (JSC) = 16.4 mA/cm2, open-circuit photo voltage (VOC) = 692 mV, fill factor = 0.734), 8.76% (JSC = 16.3 mA/cm2, VOC = 735 mV, fill factor = 0.734) and 9.12% (JSC = 16.1 mA/cm2, VOC = 745 mV, fill factor = 0.753) were obtained for H102, H105 and N719 sensitizers respectively.}, number={11-12}, journal={Synthetic Metals}, author={Chandrasekharam, M. and Rajkumar, G. and Srinivasa Rao, C. and Suresh, T. and Anil Reddy, M. and Yella Reddy, P. and Soujanya, Y. and Takeru, B. and Jun-Ho, Y. and Nazeeruddin, M.K. and et al.}, year={2011}, pages={1098–1104} }