The Experts below are selected from a list of 4119 Experts worldwide ranked by ideXlab platform

Carlo Adamo - One of the best experts on this subject based on the ideXlab platform.

  • Insights into Working Principles of Ruthenium Polypyridyl Dye-Sensitized Solar Cells from First Principles Modeling
    The Journal of Physical Chemistry C, 2011
    Co-Authors: Frédéric Labat, Ilaria Ciofini, Hrant P. Hratchian, Michael J. Frisch, Krishnan Raghavachari, Carlo Adamo
    Abstract:

    With the aim to better describe the phenomena taking place at the dye/semiconductor interface in dye-sensitized solar cells and to understand the interfacial electron Transfer from the excited dye to the semiconductor, the cis-[Ru(4,4′-COOH-2,2′-bpy)2(NCS)2]/TiO2 system has been investigated using density functional theory (DFT) in conjunction with a periodic approach and a hybrid functional. At this level of theory, the interplay of the Electronic and geometrical coupling between the semiconductor and the dye has been analyzed, and the feasibility of the interfacial Electronic Transfer has been discussed. Our results show that the Electronic Transfer is highly favorable from a thermodynamic point of view, the LUMO of the dye being significantly higher in energy than the conduction band of the semiconductor. In addition, the theoretical injection time, computed using the Newns−Anderson model, is in fair agreement with the observed value.

Frédéric Labat - One of the best experts on this subject based on the ideXlab platform.

  • Insights into Working Principles of Ruthenium Polypyridyl Dye-Sensitized Solar Cells from First Principles Modeling
    The Journal of Physical Chemistry C, 2011
    Co-Authors: Frédéric Labat, Ilaria Ciofini, Hrant P. Hratchian, Michael J. Frisch, Krishnan Raghavachari, Carlo Adamo
    Abstract:

    With the aim to better describe the phenomena taking place at the dye/semiconductor interface in dye-sensitized solar cells and to understand the interfacial electron Transfer from the excited dye to the semiconductor, the cis-[Ru(4,4′-COOH-2,2′-bpy)2(NCS)2]/TiO2 system has been investigated using density functional theory (DFT) in conjunction with a periodic approach and a hybrid functional. At this level of theory, the interplay of the Electronic and geometrical coupling between the semiconductor and the dye has been analyzed, and the feasibility of the interfacial Electronic Transfer has been discussed. Our results show that the Electronic Transfer is highly favorable from a thermodynamic point of view, the LUMO of the dye being significantly higher in energy than the conduction band of the semiconductor. In addition, the theoretical injection time, computed using the Newns−Anderson model, is in fair agreement with the observed value.

Cristián G. Sánchez - One of the best experts on this subject based on the ideXlab platform.

  • Quantum efficiency of the photo-induced Electronic Transfer in dye-TiO2 complexes.
    Physical chemistry chemical physics : PCCP, 2018
    Co-Authors: Dalma M. Marquez, Cristián G. Sánchez
    Abstract:

    We present a method based on a time-dependent self-consistent density functional tight-binding (TD-DFTB) approach, able to predict the quantum efficiency of the photoinjection process in a dye–TiO2 complex from a fully atomistic picture. We studied the process of charge Transfer of three systems with different dyes: catechol (CAT), alizarin (ALZ) and FSD101. Each system was excited with lasers of different energies in the range of 300–2500 nm, studying the efficiency of the induced charge Transfer process at the incident energies. We show that the perturbation can produce either hole Transfer or electron Transfer from the dye to the nanoparticle, therefore affecting the efficiency of the charge Transfer in the solar cell when illuminated by broadband radiation.

Gonzalo Riveros - One of the best experts on this subject based on the ideXlab platform.

  • Electronic Transfer mechanism in self-assembled monolayers of silicon
    Journal of Solid State Electrochemistry, 2019
    Co-Authors: Carolina Garín, Alejandro León, Mónica Pacheco, Gonzalo Riveros
    Abstract:

    This work presents a theoretical-experimental study on Electronic Transfer mechanism on crystal silicon surface modified with redox molecules derived from ferrocene. The surface modification consists in the reaction of hydrogenated silicon with decyl bromide (10-bromo-1-decene) activated with white light, and its subsequent reaction with monolithio-ferrocene. The samples were analyzed by X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. The layers formed are electrochemically active and present a quasi-reversible electrochemical process which is attributed to the ferrocene molecules bound to the silicon surface. In the experimental results, we found an apparent discrepancy, with respect to the results of the cyclic voltammetry, indicating that the redox centers have a diffusive behavior, like to molecules in solution, in spite of these molecules are linked to the silicon surface. While another technique indicates that these redox centers could be attached to the substrate. To understand these results, we have formulated a phenomenological model, based on a cellular automaton, that describes the mechanism of Electronic Transfer in molecules attached to the substrate. The parameters of the model are obtained from calculations of first principles, based on the density functional theory (DFT). Our results show that the Electronic Transfer mechanism is influenced by the movement of the redox centers of the molecules attached to the substrate. The latter would explain the apparent discrepancy in the experimental results.

Michael J. Frisch - One of the best experts on this subject based on the ideXlab platform.

  • Insights into Working Principles of Ruthenium Polypyridyl Dye-Sensitized Solar Cells from First Principles Modeling
    The Journal of Physical Chemistry C, 2011
    Co-Authors: Frédéric Labat, Ilaria Ciofini, Hrant P. Hratchian, Michael J. Frisch, Krishnan Raghavachari, Carlo Adamo
    Abstract:

    With the aim to better describe the phenomena taking place at the dye/semiconductor interface in dye-sensitized solar cells and to understand the interfacial electron Transfer from the excited dye to the semiconductor, the cis-[Ru(4,4′-COOH-2,2′-bpy)2(NCS)2]/TiO2 system has been investigated using density functional theory (DFT) in conjunction with a periodic approach and a hybrid functional. At this level of theory, the interplay of the Electronic and geometrical coupling between the semiconductor and the dye has been analyzed, and the feasibility of the interfacial Electronic Transfer has been discussed. Our results show that the Electronic Transfer is highly favorable from a thermodynamic point of view, the LUMO of the dye being significantly higher in energy than the conduction band of the semiconductor. In addition, the theoretical injection time, computed using the Newns−Anderson model, is in fair agreement with the observed value.