A novel donor moiety 9,9,9′9′-tetramethyl-9,9′10,10′-tetrahydro-2,10′-biacridine via one-pot C–H arylation for TADF emitters and their application in highly efficient solution-processable OLEDs

Abstract

<p>A novel donor fragment of BDMAc is synthesized <italic>via</italic> C–H arylation by the one-pot method, and three BDMAc-based TADF molecules with high efficiency are obtained. Solution processable OLEDs based on these TADF molecules exhibit a high EQE of ∼23%.</p>

Effective bipolar hosts preparedviadipole moment engineering for phosphorescent emitters and white OLEDs

“…With the increasing solvent polarity, o -CBPy also exhibits more distinct significantly red-shifted emission (41 nm) compared to o -CPPy (32 nm), indicative of the enhanced charge transfer properties. Similar to a previous report, 42 both compounds exhibit a hypochromic shift in doped PMMA films, ascribed to the suppressed molecular vibrations in a rigid substance and varied polarity of PMMA. The fluorescence quantum yields ( Φ f ) of o -CBPy and o -CPPy were measured to be 0.09 and 0.17 in toluene solution, respectively (Table 1).…”

Asymmetric sky-blue thermally-activated delayed fluorescence emitters bearing tris(triazolo)triazine moiety for solution-processable organic light-emitting diodes

“…2b), respectively. Compared to our previous reports, 51 this result demonstrates that decreasing the number of donor moieties effectively leads to blue-shifted emission owing to a reduced ICT effect. The broad and structureless shape of the PL profiles implies that the emission is mainly generated from the charge transfer (CT) state.…”

“…Two factors could be responsible for this phenomenon: (i) the suppressed molecular motions in the solid state; and (ii) and the polarity of the PMMA film. 51 Owing to the stronger ICT effect, compound TTT-2Ac shows distinct red-shifted emission spectra compared with TTT-Ac in both solution and film. Impressively, a shoulder at about 380 nm is detected for TTT-Ac , which can be attributed to emission from a localized state of the Ac unit.…”

High‐Efficiency Solution‐Processable OLEDs by Employing Thermally Activated Delayed Fluorescence Emitters with Multiple Conversion Channels of Triplet Excitons

“…As illustrated in Figurer 5f , to our best knowledge, the EQE value of 27.13% for BD‐F based device is at a record high for solution‐processed OLEDs devices. [ 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 ] It also should be noted that the solution‐processable emitters with deep‐blue or near‐infrared color still obviously lag behind others, and thus we need to pay more concentration on promoting their luminescence efficiency through elaborate molecular designing and structural regulation depicted in our work.…”