Journal ArticleDOI
Expanded Theory of H- and J-Molecular Aggregates: The Effects of Vibronic Coupling and Intermolecular Charge Transfer.
TLDR
This review outlines advances made in understanding the relationship between aggregate structure and photophysics when vibronic coupling and intermolecular charge transfer are incorporated.Abstract:
The electronic excited states of molecular aggregates and their photophysical signatures have long fascinated spectroscopists and theoreticians alike since the advent of Frenkel exciton theory almost 90 years ago. The influence of molecular packing on basic optical probes like absorption and photoluminescence was originally worked out by Kasha for aggregates dominated by Coulombic intermolecular interactions, eventually leading to the classification of J- and H-aggregates. This review outlines advances made in understanding the relationship between aggregate structure and photophysics when vibronic coupling and intermolecular charge transfer are incorporated. An assortment of packing geometries is considered from the humble molecular dimer to more exotic structures including linear and bent aggregates, two-dimensional herringbone and “HJ” aggregates, and chiral aggregates. The interplay between long-range Coulomb coupling and short-range charge-transfer-mediated coupling strongly depends on the aggregate ...read more
Citations
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Journal ArticleDOI
Aggregation-Induced Emission (AIE): A Historical Perspective.
TL;DR: This Essay discusses the AIE phenomenon from a broader perspective, with an emphasis on early observations related to AIE made long before the term was coined, with a focus on cyanine dyes such as thiazole orange or its dimers.
Journal ArticleDOI
Non-adiabatic Excited-State Molecular Dynamics: Theory and Applications for Modeling Photophysics in Extended Molecular Materials.
Tammie Nelson,Alexander J. White,Josiah A. Bjorgaard,Andrew E. Sifain,Andrew E. Sifain,Yu Zhang,Benjamin Nebgen,Sebastian Fernandez-Alberti,Dmitry Mozyrsky,Adrian E. Roitberg,Sergei Tretiak +10 more
TL;DR: This Review will describe recent theoretical advances including treatment of electronic decoherence in surface-hopping methods, the role of solvent effects, trivial unavoided crossings, analysis of data based on transition densities, and efficient computational implementations of these numerical methods.
Journal ArticleDOI
Machine Learning for Electronically Excited States of Molecules.
TL;DR: In this article, a review of machine learning for excited states of molecules is presented, focusing on not only how machine learning is employed to speed up such excited-state simulations but also how this branch of artificial intelligence can be used to advance this exciting research field in all its aspects.
Journal ArticleDOI
Charge Separation from an Intra-Moiety Intermediate State in the High-Performance PM6:Y6 Organic Photovoltaic Blend
TL;DR: It is reported that the hole transfer channel of photocharge generation is mediated by an intra-moiety excited state in a blend of donor polymer PM6 and NFA Y6 using broadband transient absorption (TA) spectroscopy, suggesting that manipulating the interplay between intra-Moiety and interfacial excited species can provide a promising route for further improving device performance.
Journal ArticleDOI
Molecular polaritons for controlling chemistry with quantum optics
TL;DR: The basic physical principles and consequences of strong light-matter coupling common to molecular ensembles embedded in UV-visible or infrared cavities are described and the competition between the collective cooperative dipolar response of a molecular ensemble and local dynamical processes that molecules typically undergo are discussed.
References
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Journal ArticleDOI
Intra- and intermolecular charge transfer in aggregates of tetrathiafulvalene-triphenylmethyl radical derivatives in solution.
Judith Guasch,Luca Grisanti,Manuel Souto,Vega Lloveras,José Vidal-Gancedo,Imma Ratera,Anna Painelli,Concepció Rovira,Jaume Veciana +8 more
TL;DR: An extensive investigation of aggregation phenomena occurring in solution for a family of electron donor-acceptor derivatives, based on polychlorotriphenylmethyl radicals linked via a vinylene-bridge to tetrathiafulvalene (TTF) units, sheds light on the reciprocal influence of intramolecular electron transfer within a dyad and the intermolecular charge transfer between the TTF residues.
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Low-temperature dynamics of weakly localized Frenkel excitons in disordered linear chains
TL;DR: A counterintuitive nonmonotonic temperature dependence of the Stokes shift is found and it is shown that depending on experimental conditions, the observed fluorescence decay time may be determined by vibration-induced intraband relaxation, rather than radiative relaxation to the ground state.
Journal ArticleDOI
Relaxation of photo-excitations in films of oligo- and poly-(para-phenylene vinylene) derivatives
TL;DR: In this paper, photo-luminescence from solid films of poly(para-phenylene vinylene) polymers and an oligomeric model system, consisting of seven repeat units, were investigated at low temperature (8 K) using time-resolved spectroscopic techniques.
Journal ArticleDOI
Temperature dependent exciton emission from herringbone aggregates of conjugated oligomers.
TL;DR: Comparison to experiments on thin films of quaterthiophene shows that the thermal coherence size is given by NT approximately 1+450/T (K) and that superradiance, which requires NT>Nth, can only be observed at temperatures less than 1 K.
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Dielectric tensor of tetracene single crystals: the effect of anisotropy on polarized absorption and emission spectra.
Silvia Tavazzi,Luisa Raimondo,Leonardo Silvestri,Peter Spearman,Andrea Camposeo,M. Polo,Dario Pisignano +6 more
TL;DR: The directions of polarization of the lowest optical transitions and the directions of the principal axes of the dielectric tensor are demonstrated not to coincide, in contrast to the assumptions typically made in the literature, thus causing the mixed transverse/longitudinal character of light propagation.