Hyperfluorescence-Based Emission in Purely Organic Materials: Suppression of Energy-Loss Mechanisms via Alignment of Triplet Excited States

Abroshan, Hadi; Coropceanu, Veaceslav; Brédas, Jean‐Luc

doi:10.1021/acsmaterialslett.0c00407

Cited by 48 publications

(64 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The polarizable continuum model 43 was used in all calculations except for the tuning procedure. A dielectric constant ε = 3 and a refractive index of 1.8 were assumed 17 . Singlet and triplet excitons are generated randomly in the lattice and allowed to move through Förster transfers, decay radiatively (fluorescence or phosphorescence) or nonradiatively, and undergo intersystem crossing according to their calculated rates.…”

Section: A Electronic Structure Calculationsmentioning

confidence: 99%

Triplet-to-Singlet Exciton Transfer in Hyperfluorescent OLED materials

Sousa

Born

Neto

et al. 2021

Preprint

View full text Add to dashboard Cite

Hyperfluorescent organic light-emitting diodes combine two kinds of dopants to maximize device efficiency: one molecule exhibiting thermally activated delayed fluorescence (TADF) and another molecule with a high fluorescence rate and narrow emission spectrum.The postulated role of a TADF sensitizer is to enable up-conversion of triplet to singlet excitons through the reverse intersystem crossing mechanism, which is followed by a Förster energy transfer to the fluorescent emitter. However, a second mechanism based on the direct triplet-to-singlet exciton transfer between TADF molecules is a priori possible, but its role in hyperfluorescence has not been investigated. Here we employ first-principles electronic-structure and kinetic Monte Carlo simulations to study the hyperfluorescence mechanism in four pairs of TADF/fluorescent emitters. We demonstrate how the tripletto-singlet energy transfer mechanism is, in some cases, the main driver for the quantum efficiency boost observed in hyperfluorescent devices.

show abstract

Section: A Electronic Structure Calculationsmentioning

confidence: 99%

Triplet-to-Singlet Exciton Transfer in Hyperfluorescent OLED materials

Sousa

Born

Neto

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…Organic light-emitting diodes (OLEDs) have received significant attention as the most demanded forthcoming display and lighting technology because of their low cost, lightweight, low power consumption, high brightness, and high contrast ( Chen et al, 2018 ; Lee et al, 2019a ; Lee et al, 2019b ; Abroshan et al, 2020a ; Abroshan et al, 2020b ; Abroshan et al, 2020c ; Abroshan et al, 2020d ). Recent developments in OLEDs with flexible panels have opened a new avenue for innovative technologies to fabricate cost-effective large-area, wearables, foldable and shape-fitting displays ( Jeong et al, 2020 ; Song et al, 2020 ; Yoo et al, 2020 ).…”

Section: Introductionmentioning

confidence: 99%

Active Learning Accelerates Design and Optimization of Hole-Transporting Materials for Organic Electronics

Abroshan

Kwak

et al. 2022

Front. Chem.

Self Cite

View full text Add to dashboard Cite

Data-driven methods are receiving increasing attention to accelerate materials design and discovery for organic light-emitting diodes (OLEDs). Machine learning (ML) has enabled high-throughput screening of materials properties to suggest new candidates for organic electronics. However, building reliable predictive ML models requires creating and managing a high volume of data that adequately address the complexity of materials’ chemical space. In this regard, active learning (AL) has emerged as a powerful strategy to efficiently navigate the search space by prioritizing the decision-making process for unexplored data. This approach allows a more systematic mechanism to identify promising candidates by minimizing the number of computations required to explore an extensive materials library with diverse variables and parameters. In this paper, we applied a workflow of AL that accounts for multiple optoelectronic parameters to identify materials candidates for hole-transport layers (HTL) in OLEDs. Results of this work pave the way for efficient screening of materials for organic electronics with superior efficiencies before laborious simulations, synthesis, and device fabrication.

show abstract

“…Several recent reports have demonstrated the potential of this approach to achieve very high efficiency in deep blue OLEDs, [17][18][19][20][21] generating accompanying theoretical interest as well. [22][23][24] In practice, direct charge recombination on the FE will predominantly generate non-emissive triplet excitons. Dexter energy transfer (DET) from the high energy triplet states of the TADF-S to the lower energy FE triplet can further reduce emission efficiency.…”

Section: Introductionmentioning

confidence: 99%