Theoretical Prediction of Triplet–Triplet Energy Transfer Rates in a Benzophenone–Fluorene–Naphthalene System

Excitation energy transfer (EET) is a process where the electronically excitation is transferred from a donor to an acceptor. EET is widely seen in both natural and in artificial systems, such as light-harvesting in photosynthesis, the fluorescence resonance energy transfer technique, and the design of light-emitting molecular devices. In this work, we outline the theories describing both singlet and triplet EET (SEET and TEET) rates, with a focus on the physical nature and computational methods for the electronic coupling factor, an important parameter in predicting EET rates. The SEET coupling is dominated by the Coulomb coupling, and the remaining short-range coupling is very similar to the TEET coupling. The magnitude of the Coulomb coupling in SEET can vary much, but the contribution of shortrange coupling has been found to be similar across different excited states in naphthalene. The exchange coupling has been believed to be the major physical contribution to the shortrange coupling, but it has been pointed out that other contribution, such as the orbital overlap effect is similar or even larger in strength. The computational aspects and the subsequent physical implication for both SEET and TEET coupling values are summarized in this work.

show abstract

“…Unrestricted Kohn–Sham solution is also seen. The constrained density functional theory is one possible way to obtain the diabatic states.…”

Section: Computation Methods For Eet Couplingmentioning

confidence: 99%

Theory and calculation for the electronic coupling in excitation energy transfer

You

Hsu

2013

Int. J. Quantum Chem.

129

151

View full text Add to dashboard Cite

show abstract

“…Moreover, still within DFT, the constrained density functional theory discussed above represents another possible way to obtain the diabatic states and it has been used to get TET couplings. [109][110][111][112] For singlet energy transfer, this approach is much more computationally intensive as a singlet excited state typically involves several configurations. This means that one should consider many terms in configuration interactions, which rapidly increases the computational costs.…”

Section: Electronic Couplingsmentioning

confidence: 99%

Quantum Chemical Studies of Light Harvesting

2016

View full text Add to dashboard Cite

The design of optimal light-harvesting (supra)molecular systems and materials is one of the most challenging frontiers of science. Theoretical methods and computational models play a fundamental role in this difficult task, as they allow the establishment of structural blueprints inspired by natural photosynthetic organisms that can be applied to the design of novel artificial light-harvesting devices. Among theoretical strategies, the application of quantum chemical tools represents an important reality that has already reached an evident degree of maturity, although it still has to show its real potentials. This Review presents an overview of the state of the art of this strategy, showing the actual fields of applicability but also indicating its current limitations, which need to be solved in future developments.

show abstract

“…In this work, we make use of constrained DFT (cDFT) [24][25][26][27] in combination with linear-scaling DFT (as implemented in the ONETEP code [28]), applying it to intermolecular charge-transfer in two nearest-neighbour dimers taken from the pentacene crystal structure. The cDFT method has been applied to a wide variety of molecular systems, to date, in the context of CT excitation energies [29][30][31][32], electronic couplings [33][34][35], electron transfer [36][37][38][39] and molecular dynamics [40,41]. A largely unresolved issue in this context, however, is that of achieving supercell convergence of CT excitations in extended models suitable for capturing the screening and hybridisation effects encountered in realistic systems.…”

Section: Introductionmentioning

confidence: 99%

Supercell convergence of charge-transfer energies in pentacene molecular crystals from constrained DFT

et al. 2016

View full text Add to dashboard Cite

Singlet fission (SF) is a multi-exciton generation process that could be harnessed to improve the efficiency of photovoltaic devices. Experimentally, systems derived from the pentacene molecule have been shown to exhibit ultrafast SF with high yields. Charge-transfer (CT) configurations are likely to play an important role as intermediates in the SF process in these systems. In molecular crystals, electrostatic screening effects and band formation can be significant in lowering the energy of CT states, enhancing their potential to effectively participate in SF. In order to simulate these, it desirable to adopt a computational approach which is acceptably accurate, relatively inexpensive, which and scales well to larger systems, thus enabling the study of screening effects. We propose a novel, electrostatically-corrected constrained Density Functional Theory (cDFT) approach as a low-cost solution to the calculation of CT energies in molecular crystals such as pentacene. Here we consider an implementation in the context of the ONETEP linear-scaling DFT code, but our electrostatic correction method is in principle applicable in combination with any constrained DFT implementation, also outside the linear-scaling framework. Our newly developed method allows us to estimate CT energies in the infinite crystal limit, and with these to validate the accuracy of the cluster approximation.

show abstract

Theoretical Prediction of Triplet–Triplet Energy Transfer Rates in a Benzophenone–Fluorene–Naphthalene System

Cited by 17 publications

References 82 publications

Theory and calculation for the electronic coupling in excitation energy transfer

Theory and calculation for the electronic coupling in excitation energy transfer

Quantum Chemical Studies of Light Harvesting

Supercell convergence of charge-transfer energies in pentacene molecular crystals from constrained DFT

Contact Info

Product

Resources

About