Publicaciones 2011-2020

@article{mendizabal2017electronic,
title = {Electronic and Optical Properties of Metalloporphyrins of Zinc on Tio2 Cluster in Dye-Sensitized Solar-Cells (Dssc). A Quantum Chemistry Study},
author = { F. Mendizabal and R. Mera-Adasme and W.H. Xu and D. Sundholm},
url = {/brokenurl#<Go to ISI>://WOS:000409548200006},
doi = {10.1039/c7ra08648b},
year = {2017},
date = {2017-01-01},
journal = {Rsc Advances},
volume = {7},
number = {68},
pages = {42677-42684},
abstract = {Dye-sensitized solar-cell (DSSC) systems have been investigated by calculating light-absorption and electron-injection processes of the LD13 ([5,15-bis(2,6-(1,1-dimethylethyl)-phenyl)-10-4-dimethylaminophenylethynyl-20-4-carboxy phenylethynyl porphyrinato]zinc-(II)) and YD2-o-C8 ([5,15bis( 2,6-dioctoxyphenyl)-10-(bis(4-hexylphenyl)amino-20-4-carboxyphenylethynyl)porphyrinato]zinc-(II)) dyes adsorbed on a TiO2 cluster simulating the semiconductor. The binding energy of the dyes with the TiO2 clusters has been calculated at the density functional theory (DFT) level using the B3LYP and CAM-B3LYP functionals. The electronic excitation energies have been calculated at the time-dependent DFT (TDDFT) level for the dyes in the gas and solvent phase employing the B3LYP, CAM-B3LYP and BHLYP functionals. The calculated excitation energies have been compared to values obtained at the algebraic diagrammatic construction through second order (ADC(2)) level of theory. The TDDFT calculations with the B3LYP in tetrahydrofuran solvent with the dye and dye-TiO2 models yield excitation energies that agree well with the transitions in the experimental absorption spectra. Changes in the free energy for electron injection support the better performance of the dyes on the TiO2 clusters.},
keywords = {approximation, efficient, energy-levels, excited-states, performance, porphyrin pseudopotentials, sensitizers, surface, thermochemistry},
pubstate = {published},
tppubtype = {article}
}

@article{RN359,
title = {Electronic Structure and Optical Properties Calculation of Zn-Porphyrin with N-Annulated Perylene Adsorbed on Tio2 Model for Dye-Sensitized Solar Cell Applications: A Dft/Td-Dft Study},
author = { K. Paredes-Gil and F. Mendizabal and D. Paez-Hernandez and R. Arratia-Perez},
url = {/brokenurl#<Go to ISI>://WOS:000389089900058},
doi = {10.1016/j.commatsci.2016.09.042},
issn = {0927-0256},
year = {2017},
date = {2017-01-01},
journal = {Computational Materials Science},
volume = {126},
pages = {514-527},
publisher = {2016 Elsevier B.V.},
abstract = {The current work scrutinizes the chemical behavior of a set of promissory dyes, the Zn-porphyrins with N-annulated Perylene, WW3m-WW8m, within the most important steps in the solar cell: photoexcitation, electron injection and dye regeneration. The photoexcitation step was studied through TD-DFT frame-work, finding that the most intense band in WW4m, WW6m-WW8m corresponds to the electronic transition of the frontier orbitals HOMO-LUMO. Among these, WW6m is highlighted, because the electronic density of the LUMO is localized over the anchoring group. Therefore, the presence of two ethynylene spacers in the WW6m porphyrin originate an enhancement in the light absorption. On the other hand, we analyze the electron injection modelling two (mono and bidentate) adsorbing modes in WW3m
@Ti0(2)-WW8m
@TiO2 using DFT (B3LYP+D3) calculations. Adsorption energies. show that WW3m
@Ti0(2)-WW8m
@TiO2 are coordinated in bidentate mode. In this sense, to analyze the density of states (DOS) we found that WW6m
@TiO2 present the narrowest band gap (1.53 eV), promoting an easy electron injection, which could explain the origin of the highest overall efficiency of the solar cell for this porphyrin. Finally, dye regeneration, was studied through the free energy associated, Delta G(regen,) the values are between -6.61 and -6.93 eV for WW3m
@Ti02-WW8m
@TiO2 showing that this step is spontaneous and similar in all porphyrins.},
keywords = {computational density-functional dye, efficiency, electrochemistry, energy-levels, excited-states, families, light-harvesting model, n-annulated n719 perylene properties, related solar spectroscopic studies, theory, tio2 zn-porphyrin},
pubstate = {published},
tppubtype = {article}
}

@article{RN28i,
title = {Influence of the Nature of the Absorption Band on the Potential Performance of High Molar Extinction Coefficient Ruthenium(Ii) Polypyridinic Complexes as Dyes for Sensitized Solar Cells},
author = { F. Gajardo and M. Barrera and R. Vargas and I. Crivelli and B. Loeb},
url = {/brokenurl#<Go to ISI>://WOS:000292010000012},
doi = {10.1021/ic1020862},
issn = {0020-1669},
year = {2011},
date = {2011-01-01},
journal = {Inorganic Chemistry},
volume = {50},
number = {13},
pages = {5910-5924},
abstract = {When tested in solar cells, ruthenium polypyridinic dyes with extended pi systems show an enhanced light-harvesting capacity that is not necessarily reflected by a high (collected electrons)/(absorbed photons) ratio. Provided that metal-to-ligand charge transfer bands, MLCT, are more effective, due to their directionality, than intraligand (IL) pi-pi* bands for the electron injection process in the solar cell, it seems important to explore and clarify the nature of the absorption bands present in these types of dyes. This article aims to elucidate if all the absorbed photons of these dyes are potentially useful in the generation of electric current. In other words, their potentiality as dyes must also be analyzed from the point of view of their contribution to the generation of excited states potentially useful for direct injection. Focusing on the assignment of the absorption bands and the nature of the emitting state, a systematic study for a series of ruthenium complexes with 4,4'-distyryl-2,2'-dipyridine (LH) and 4,4'-bis[p-(dimethylamino)-alpha-styryl]-2,2'-bipyridine (LNMe2) "chromophoric" ligands was undertaken. The observed experimental results were complemented with TDDFT calculations to elucidate the nature of the absorption bands, and a theoretical model was proposed to predict the available energy that could be injected from a singlet or a triplet excited state. For the series studied, the results indicate that the percentage of MLCT character to the anchored ligand for the lower energy absorption band follows the order [Ru(deebpy)(2)(LNMe2)](PF6)(2) > [Ru(deebpy)(2)(LH)] (PF6)(2) > [Ru(deebpy)(LH)(2)](PF6)(2), where deebpy is 4,4'-bis(ethoxycarbonyl)-2,2'-bipyridine, predicting that, at least from this point of view, their efficiency as dyes should follow the same trend.},
keywords = {charge-transfer conversion, correlation-energy, density, excited-states, films, light, nanocrystalline optical-properties, sensitizers, tio2},
pubstate = {published},
tppubtype = {article}
}