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Your search keyword '"De Angelis, Filippo"' showing total 261 results
Start Over Author "De Angelis, Filippo" Publisher american chemical society
261 results on '"De Angelis, Filippo"'

3. The Ferroelectric-Ferroelastic Debate about Metal Halide Perovskites

Author

Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Generalitat de Catalunya, Ambrosio, Francesco [0000-0002-6388-9586], De Angelis, Filippo [0000-0003-3833-1975], Goñi, Alejandro R. [0000-0002-1193-3063], Ambrosio, Francesco, De Angelis, Filippo, Goñi, Alejandro R., Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Generalitat de Catalunya, Ambrosio, Francesco [0000-0002-6388-9586], De Angelis, Filippo [0000-0003-3833-1975], Goñi, Alejandro R. [0000-0002-1193-3063], Ambrosio, Francesco, De Angelis, Filippo, and Goñi, Alejandro R.

Abstract

Metal halide perovskites (MHPs) are solution-processed materials with exceptional photoconversion efficiencies that have brought a paradigm shift in photovoltaics. The nature of the peculiar optoelectronic properties underlying such astounding performance is still controversial. The existence of ferroelectricity in MHPs and its alleged impact on photovoltaic activity have fueled an intense debate, in which unanimous consensus is still far from being reached. Here we critically review recent experimental and theoretical results with a two-fold objective: we argue that the occurrence of ferroelectric domains is incompatible with the A-site cation dynamics in MHPs and propose an alternative interpretation of the experiments based on the concept of ferroelasticity. We further underline that ferroic behavior in MHPs would not be relevant at room temperature or higher for the physics of photogenerated charge carriers, since it would be overshadowed by competing effects like polaron formation and ion migration.

Published
2022

22. Ab initio molecular dynamics simulations of elimination reactions in water solution: Exploring the borderline region between the E1cb and E2 reaction mechanisms

Author

De Angelis, Filippo, Tarantelli, Francesco, and Alunni, Sergio

Subjects
Molecular dynamics -- Analysis, Water -- Atomic properties, Elimination reactions -- Analysis, Halides -- Chemical properties, Chemicals, plastics and rubber industries
Abstract

Ab initio molecular dynamics simulations in water solution are used to explore the mechanism of base-induced beta-elimination reactions in systems activated by the pyridyl ring, with halogen leaving groups. The results have shown that the reaction mechanism effectively evolves through the potential energy region of the carbanion, where the carbon-fluoride bond breaks only after the carbon-hydrogen bond.

Published
2006

23. Interplay of stereoelectronic and environmental effects in tuning the structural and magnetic properties of a prototypical spin probe: Further insights from a first principle dynamical approach

Author

Pavone, Michele, Cimino, Paola, De Angelis, Filippo, and Barone, Vincenzo

Subjects
Aqueous solution reactions -- Research, Molecular dynamics -- Research, Tertiary butyl compounds -- Chemical properties, Nitrogen oxide -- Chemical properties, Chemistry
Abstract

The nitrogen isotropic hyperfine coupling constant (hcc) and the g tensor of a phototypical spin probe (dl-tert-butyl nitroxide, DTBN) in aqueous solution was investigated by means of an integrated computational approach including Car-Parinello molecular dynamics and quantum mechanical calculations involving a discrete-continuum embedding. The quantitative agreement between computed and experimental parameters fully validates the integrated approach.

Published
2006

24. Terpyridine Zn(II), Ru(III), and Ir(III) complexes: The relevant role of the nature of the metal ion and of the ancillary ligands on the second-order nonlinear response of terpyridines carrying electron donor or electron acceptor groups

Author

Tessore, Francesca, Roberto, Dominique, Ugo, Renato, Pizzotti, Maddalena, Quici, Silvio, Cavazzini, Marco, Bruni, Silvia, and De Angelis, Filippo

Subjects
Pyridine -- Chemical properties, Zinc compounds -- Chemical properties, Iridium -- Chemical properties, Chemistry
Abstract

Coordination of 4'-(C6H4-p-X)-2,2':6',2'-terpyridines[X = NO2, NBu2, (E)-CH=CH-C6H4-p-NBu2, (E,E)-(CH=CH)2-C6H4-p-NMe2] to Zn(II), Ru(III), and Ir(III) metal centers induces a significant enhancement of the absolute value of their second-order nonlinear optical (NLO) response. Varying the nature of the metal center, the second order NLO response shifts from positive to negative, being controlled by metal-to-ligand, ligand-to-metal or intraligand charge-transfer transitions.

Published
2005

25. Absorption spectrum and solvatochromism of the [Ru(4,4'-COOH-2,2'-bpy)(sub 2)(NCS)(sub 2)] molecular dye by time dependent density functional theory

Author

Fantacci, Simona, De Angelis, Filippo, and Selloni, Annabella

Subjects
Density functionals -- Usage, Ruthenium -- Chemical properties, Absorption spectra -- Research, Chemistry
Abstract

The electronic, structural and spectroscopic properties of the [Ru(4,4'-COOH-2,2'-bpy)(sub 2)(NCS)(sub 2)] complex (N3) in vacuo and in ethanol and water solvents are investigated by means of combined Time dependent density functional theory (DFT/TD-DFT) calculations. DFT/TD-DFT calculations are capable of accurately describing the spectral features and solvatochromism of the N3 sensitizer.

Published
2003

27. Glutathione transferase: A first-principles study of the active site

Author

Rignanese, Gian-Marco, De Angelis, Filippo, Melchionna, Simone, and De Vita, Alessandro

Subjects
Binding sites (Biochemistry) -- Research, Chemical reactions -- Research, Chemistry
Abstract

A first-principles study of the active site with regard to glutahtione transferase is presented.

Published
2000

31. Outstanding passivation effect by a mixed-salt interlayer with internal interactions in perovskite solar cells

Author

Yang, Bowen, Suo, Jiajia, Mosconi, Edoardo, Ricciarelli, Damiano, Tress, Wolfgang, De Angelis, Filippo, Kim, Hui-Seon, Hagfeldt, Anders, Yang, Bowen, Suo, Jiajia, Mosconi, Edoardo, Ricciarelli, Damiano, Tress, Wolfgang, De Angelis, Filippo, Kim, Hui-Seon, and Hagfeldt, Anders

Abstract

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Energy Letters, © 2020 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acsenergylett.0c01664, Nonradiative recombination is a major limiting factor in obtaining efficient metal-halide perovskite photovoltaics. Here, a passivation treatment is developed by applying a mixture of a new ammonium salt, CF3(CF2)2CH2NH3I (HBAI), and a conventional formamidinium halide, FAX, on top of the 3D perovskite bulk film. The introduction of such an optimized passivation layer effectively suppressed charge recombination by passivating the surface traps of the 3D perovskite film, enabling a wellmatched energy alignment at the interface of perovskite/HTM, leading to a high power conversion efficiency (PCE) of over 23% from current−voltage (I−V) measurements and a stabilized 22.7% PCE, owing to a substantial VOC improvement (above 80 mV on average), coupled with an improved stability.

Published
2020

44. Dye-Sensitized Photocatalytic Hydrogen Generation: Efficiency Enhancement by Organic Photosensitizer-Coadsorbent Intermolecular Interaction

Author

Manfredi, N, Monai, M, Montini, T, Peri, F, De Angelis, F, Fornasiero, P, Abbotto, A, Manfredi, Norberto, Monai, Matteo, Montini, Tiziano, Peri, Francesco, De Angelis, Filippo, Fornasiero, Paolo, Abbotto, Alessandro, Manfredi, N, Monai, M, Montini, T, Peri, F, De Angelis, F, Fornasiero, P, Abbotto, A, Manfredi, Norberto, Monai, Matteo, Montini, Tiziano, Peri, Francesco, De Angelis, Filippo, Fornasiero, Paolo, and Abbotto, Alessandro

Abstract

Dye-sensitized photocatalytic H2 generation has been investigated using a metal-free phenothiazine-based donor-acceptor sensitizer (PTZ-GLU) in combination with coadsorbents. The coadsorption of the PTZ-GLU dye, functionalized with a glucose end-group, in combination with a glucose-based coadsorbent, afforded improved photocatalytic activity compared to the absence of coadsorbents, to the use of a conventional (chenodeoxycholic acid) coadsorbent, or by replacing the dye glucose functionality with an alkyl chain. The results suggest the strategic role of directional intermolecular dye-coadsorbent interactions on the semiconductor surface, as confirmed by first principles computational modeling, which likely suppressed detrimental recombination processes.

Published
2018

45. Fluorinated [beta]-diketonate diglyme lanthanide complexes as new second-order nonlinear optical chromosomes: the role of f electrons in the dipolar and octupolar contribution to quadratic hyperpolarizability

Author

Valore, Adriana, Cariati, Elena, Righetto, Stefania, Roberto, Dominique, Tessore, Francesca, Ugo, Renato, Fragala, Ignazio L., Fragala, Maria Elena, Malandrino, Graziella, De Angelis Filippo, Ledoux-Rak, Isabelle, Belpassi, Leonardo, Khuyen Hoang Thi, and Zyss, Joseph

Subjects
Ethers -- Chemical properties, Fluorination -- Analysis, Nonlinear optics -- Analysis, Rare earth metals -- Chemical properties, Rare earth metals -- Optical properties, Chemistry
Abstract

The second-order nonlinear optical (NLO) properties of [Ln[(hfac).sub.3](diglyme)] (hfac = hexafluoroacetylacetonate, diglyme = bis(2-methoxyethyl)ether, Ln = La, Ce, Pr, Sm, Eu, Gd, Er, Lu) complexes are examined for providing evidence for the relevant role of f electrons in tuning the second-order NLO response dominated by the octupolar contribution. The lanthanide NLO chromophores have allowed a clean valuation of the affect of f electrons on the quadratic hyperpolarizability and on its dipolar and octupolar contributions.

Published
2010

46. Absorption and emission of the apigenin and luteolin flavonoids: a TDDFT investigation

Author

Amat, Anna, Clementi, Catia, De Angelis, Filippo, Sgamellotti, Antonio, and Fantacci, Simona

Subjects
Carbonyl compounds -- Chemical properties, Carbonyl compounds -- Electric properties, Density functionals -- Usage, Bioflavonoids -- Chemical properties, Bioflavonoids -- Structure, Flavones -- Chemical properties, Flavones -- Structure, Flavonoids -- Chemical properties, Flavonoids -- Structure, Substitution reactions -- Analysis, Chemicals, plastics and rubber industries
Published
2009

47. Ab initio prediction of the emission color in phosphorescent iridium(III) complexes for OLEDs

Author

De Angelis, Filippo, Santoro, Fabrizio, Nazeruddin, Mohammad K., and Barone, Vincenzo

Subjects
Density functionals -- Usage, Iridium -- Optical properties, Iridium -- Chemical properties, Quantum theory -- Analysis, Spin coupling -- Analysis, Organic semiconductors -- Structure, Organic semiconductors -- Optical properties, Chemicals, plastics and rubber industries
Published
2008

48. Molecular engineering of organic sensitizers for dye-sensitized solar cell applications

Author

Hagberg, Daniel P., Jun-Ho Yum, HyoJoong Lee, De Angelis, Filippo, Marinado, Tannia, Karlsson, Karl Martin, Humphry-Baker, Robin, Licheng Sun, Hagfeldt, Anders, Gratzel, Michael, and Nazeeruddin, Md. K.

Subjects
Electrolytes -- Chemical properties, Solar batteries -- Composition, Solar cells -- Composition, Titanium -- Chemical properties, Chemistry
Abstract

Novel unsymmetrical organic sensitizers comprising donor, electron-conducting, and anchoring groups are engineered at a molecular level and are prepared for sensitization of mesoscopic titanium dioxide injection solar cells. The photovoltaic performance of D5, D7, D9 and D11 sensitizers in liquid- and solid-state-based electrolytes is examined.

Published
2008

49. Synthesis, characterization, and DFT/TD-DFT calculations of highly phosphorescent blue light-emitting anionic iridium complexes

Author

Di Censo, Davide, Fantacci, Simona, De Angelis, Filippo, Klein, Cedric, Evans, Nick, Kalyanasundaram, K., Bolink, Henk J., Gratzel, Michael, and Nazeeruddin, Mohammad K.

Subjects
Iridium -- Structure, Iridium -- Chemical properties, Iridium -- Mechanical properties, Chemical synthesis -- Analysis, Density functionals -- Analysis, Nuclear magnetic resonance spectroscopy -- Analysis, Chemistry
Abstract

The synthesis and characterization of highly phosphorescent blue-light-emitting anionic iridium complexes are described. Density functional theory (DFT) and time dependent-DFT calculations are performed on the ground and excited states of these complexes in order to provide insights into the structural electronic and optical properties of these systems.

Published
2008

50. Time-dependent density functional theory investigations on the excited states of Ru(II)-sensitized Ti[O.sub.2] nanoparticles: the role of sensitizer protonation

Author

De Angelis, Filippo, Fantacci, Simona, Selloni, Annabella, Nazeeruddin, Mohammad K., and Gratzel, Michael

Subjects
Absorption spectra -- Research, Density functionals -- Usage, Nanoparticles -- Research, Rubidium -- Chemical properties, Titanium -- Atomic properties, Titanium -- Optical properties, Titanium -- Chemical properties, Chemistry
Abstract

The article discusses the importance of the protonation of the sensitizer on the excited states of the Ru(II)-sensitized Ti[O.sub.2] nanoparticles. The protonation is found to highly affect the Ti[O.sub.2] positioning in these particles.

Published
2007

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