Through-space charge transfer hexaarylbenzene dendrimers with thermally activated delayed fluorescence and aggregation-induced emission for efficient solution-processed OLEDs

Abstract

Through-space charge transfer hexaarylbenzene dendrimers containing circularly-arrayed electron donors and acceptors exhibit thermally activated delayed fluorescence and aggregation-induced emission effects, giving EQE of 14.2% for solution-processed OLEDs.

Revealing resonance effects and intramolecular dipole interactions in the positional isomers of benzonitrile-core thermally activated delayed fluorescence materials

“…More recently, through-space D-A interactions and non-overlapping single molecule resonance structures have also been shown to deliver outstanding TADF performance. [9][10][11][12] Reducing this gap leads to exponentially faster reverse intersystem crossing (rISC), which enables triplets to be harvested for emission. The rISC is mediated by second order spin-vibronic coupling between the CT triplet ( 3 CT) and a local triplet state ( 3 LE) of either the donor or acceptor.…”

Tris(triazolo)triazine-based emitters for solution-processed blue thermally activated delayed fluorescence organic light-emitting diodes

“…Typically, a small DE ST is achieved by the spatial separation of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). The classic design strategies are based on the combination of donor and acceptor groups and their small electronic coupling either via (1) a twisted intramolecular charge transfer [6][7][8][9][10][11] transition, (2) a through-space charge-transfer transition, 7,8,12 (3) a spiroconjugation charge transfer transition 13,14 or (4) an alternating HOMO/LUMO distribution in p,n-doped polycyclic aromatic hydrocarbons, termed a multi-resonance TADF transition. 2,[15][16][17][18] By employing solution-based processing techniques, [19][20][21] large-area OLEDs becomes simpler and more cost-efficient to fabricate.…”

Suppression of Concentration Quenching in Ortho‐Substituted Thermally Activated Delayed Fluorescence Emitters

“…Molecular aggregation in an emissive layer can alter the opto–electronic properties of the material with the formation of a non‐emissive S 1 state being a possible reason for concentration quenching. In order to evaluate the nature of intermolecular states in an oBFCzTrz film, we randomly extracted from the MD simulations 1200 dimers and 500 trimers of oBFCzTrz where the inter‐COM distances are within 9.45 Å.…”