Novel thermally activated delayed fluorescence materials by high-throughput virtual screening: going beyond donor–acceptor design

Zhao, Ke; Omar, Ömer H.; Nematiaram, Tahereh; Padula, Daniele; Troisi, Alessandro

doi:10.1039/d1tc00002k

Cited by 40 publications

(40 citation statements)

References 84 publications

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“…For some OLED molecules, it has also been observed to converge onto a different excited state due to a poor orbital guess or degeneracy. 100 In this work no collapses onto the ground state were observed. However, large initial variations between basis sets were observed, indicating the presence of local minima.…”

Section: B Basis Set Effectsmentioning

confidence: 51%

Transition-Based Constrained DFT for the Robust and Reliable Treatment of Excitations in Supramolecular Systems

Stella¹,

Kritam²,

Genovese³

et al. 2021

Preprint

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Despite the variety of available computational approaches, state-of-the-art methods for calculating excitation energies such as time-dependent density functional theory (TDDFT), are typically computationally demanding and thus limited to moderate system sizes. Here, we introduce a new variation of constrained DFT (CDFT), implemented in the wavelet-based BigDFT code, wherein the constraint corresponds to a particular transition (T) between occupied and virtual orbitals, rather than a region of the simulation space as in traditional CDFT. In this work, we perform benchmark T-CDFT calculations for a set of gas phase acene molecules and OLED emitters and compare them to ∆SCF and TDDFT results, for different functionals and basis sets. For both classes of molecules, we find that T-CDFT based on semi-local functionals is comparable to hybrid functional results from ∆SCF and TDDFT. Furthermore, T-CDFT proves to be more robust than ∆SCF and does not suffer from the well-known problems encountered when applying TDDFT to charge-transfer (CT) states, and is therefore equally applicable to both local excitations and CT states. Finally, since T-CDFT is designed for large systems and has been implemented in linear-scaling BigDFT, it is ideally suited for exploring the effects of explicit environments on excitation energies, paving the way for future simulations of excited states in complex realistic morphologies, such as those which occur in OLED materials.

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Section: B Basis Set Effectsmentioning

confidence: 51%

Transition-Based Constrained DFT for the Robust and Reliable Treatment of Excitations in Supramolecular Systems

Stella¹,

Kritam²,

Genovese³

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…A distinct but related form of validation is the rediscovery of molecules already known to have the desired property from a database that is not biased toward this property. A similar method was used to validate the screening of molecular semiconductors for SF, 37 TADF 367 and electron acceptors for OPV. 295 In all these cases less than 0.5% of the screened materials had the desirable property but a fraction of them were already known to possess this property providing a good statistical validation of the procedure.…”

Section: Discussionmentioning

confidence: 99%

“…One immediate advantage of using these X-ray geometries is that the conformational search and energy optimisation step can be omitted with a substantial reduction of computational time. In our previous works to find SF 37 and TADF 367 candidates among the CSD, we could directly evaluate the low excited state energies and oscillator strengths on experimental geometries. Geometry optimisation was performed only on the most promising candidates computed as isolated molecules, most of which retained their desirable properties after optimisation.…”

Section: Methods To Sample the Chemical Spacementioning

confidence: 99%

High-throughput virtual screening for organic electronics: a comparative study of alternative strategies

et al. 2021

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“…This database was recently used to identify novel thermally activated delayed fluorescence materials. 98 For the purpose of the present study we have reduced the database to a set of materials for which S 1 is optically allowed and very bright (oscillator strength larger than 0.5), which are expected to generate broad excitonic bands, leading to 2227 crystalline structures.…”

Section: Methods and Computational Detailsmentioning

confidence: 99%

Bright Frenkel Excitons in Molecular Crystals: A Survey

2021

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We computed the optical properties of a large set of molecular crystals (∼2200 structures) composed of molecules whose lowest excited states are strongly coupled and generate wide excitonic bands. Such bands are classified in terms of their dimensionality (1-, 2-, and 3-dimensional), the position of the optically allowed state in relation with the excitonic density of states, and the presence of Davydov splitting. The survey confirms that one-dimensional aggregates are rare in molecular crystals highlighting the need to go beyond the simple low-dimensional models. Furthermore, this large set of data is used to search for technologically interesting and less common properties. For instance, we considered the largest excitonic bandwidth that is achievable within known molecular crystals and identified materials with strong super-radiant states. Finally, we explored the possibility that strong excitonic coupling can be used to generate emissive states in the near-infrared region in materials formed by molecules with bright visible absorption and we could identify the maximum allowable red shift in this material class. These insights with the associated searchable database provide practical guidelines for designing materials with interesting optical properties.

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Novel thermally activated delayed fluorescence materials by high-throughput virtual screening: going beyond donor–acceptor design

Abstract: A series of candidates of thermally activated delayed fluorescence (TADF) materials, which have important applications in organic light emitting diodes devices, are identified by a high-throughput virtual screening of a...

Cited by 40 publications

References 84 publications

Transition-Based Constrained DFT for the Robust and Reliable Treatment of Excitations in Supramolecular Systems

Transition-Based Constrained DFT for the Robust and Reliable Treatment of Excitations in Supramolecular Systems

High-throughput virtual screening for organic electronics: a comparative study of alternative strategies

Bright Frenkel Excitons in Molecular Crystals: A Survey

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