Novel dendritic large molecules as solution-processable thermally activated delayed fluorescent emitters for simple structured non-doped organic light emitting diodes

Abstract

The structural optimization of a TADF emissive core with suitable dendrons leads to simple structured solution processable non-doped OLEDs with superior performances.

Design of Blue Thermally Activated Delayed Fluorescent Emitter with Efficient Exciton Gathering Property for High-Performance Fully Solution-Processed Hybrid White OLEDs

“…If the introduced bulky units are not suitable, it will not only destroy the TADF feature but also dramatically decrease the device efficiency. − Therefore, the development of fully solution-processed TADF-phosphor (T–P) hybrid WOLEDs brings rigorous demands for the TADF blue emitter. Normally, with the improved design strategy of the molecule, the general requirements, such as high triplet energy, good film-forming ability, and adequate solvent-resistant ability, might be easy to achieve. − Nevertheless, the triplet-polaron quenching, low-energy exciplex state, and electromer formation between the bulky units are still the big challenges for restraining of energy leakage. In view of no guidelines for accurately enhancing the molecular weight without sacrificing the TADF feature and electroluminescent efficiency, the fully solution-processed TADF-based hybrid WOLEDs have not been fabricated up to now.…”

Exciplex Formation and Electromer Blocking for Highly Efficient Blue Thermally Activated Delayed Fluorescence OLEDs with All‐Solution‐Processed Organic Layers

“…As ar esult, the achieved fully solution-processed TADF blue OLEDs exhibit al ow turn-on voltage and an excellent EL efficiency,w hich outperforms most of the reported doped device with vacuum deposited EML. This work [13] PEDOT:PSS j PhCzDSO2 j TPBi 5.0 4546 8.8 4.0 0.19, 0.37 [8c] PEDOT:PSS j m-DTPACO j TmPyPB 3.9 4.8 2.4 0.15, 0.28 [14] PEDOT:PSS j DCzDMAC-DPS j TPBi 5.2 3.8 2.2 0.18, 0.27 [15] PEDOT:PSS j TPPOCz j TmPyPB j TPBi 6.2 6119 3.2 2.0 0.26, 0.31 [16] PEDOT:PSS j PBD-10 j DPEPO j TmPyPB 3.8 13.5 7.3 0.20, 0.29 [4c] PEDOT:PSS j P-Ac95-TRZ05 j TSPO1 j TmPyPB 3.2 6150 24.8 12.1 0.18, 0.27 [4d] PEDOT:PSS j TFB j B-oTC j DPEPO j TyPMPB 3.9 4351 37.3 19.1 0.15, 0.26 [17] PEDOT:PSS j poly-TPD j P3-P12 j TmPyPB 3.2 9.0 4.0 0.22, 0.37 [18] PEDOT:PSS j PVK j TB14CZ-ACTRZ j TPBi 4.0 2622 13.9 5.5 0.21, 0.42 [19] DPEDOT:PSS j PVK j SiCz:4CzFPN j EMPA j TPBi 36.1 20.0 0.16, 0.25 [5] PEDOT:PSS j PVK PEDOT:PSS j PYD2:emitter j TPBi 4.5 10 413 9.5 5.6 0.18, 0.23 [3b] PEDOT:PSS j mCP:5CzCF3Ph j TmPyPB 3.9 11.8 5.2 0.21, 0.33 [3c] [a] N = Non-doped device.…”

Recent progress in thermally activated delayed fluorescence emitters for nondoped organic light-emitting diodes

“…Using the same self-host strategy, they also decorated the emitting core 4,4 0 ,4 00 -(1,3,5-triazine-2,4,6-triyl) tris(N,N-diphenylaniline) (TTPA-TRZ) with Cz-based dendrons for high-performance solution-processed nondoped OLEDs (164 and 165). 138 Choi et al 139 also designed two dendrimers 166 and 167 by choosing the efficient nondoped green TADF material 142 as the emitting core. Using a methylene group as the linkage can effectively disrupt the conjugation between the peripheral Czbased dendrons and the emitter core.…”

“…Choi et al 139 also designed two dendrimers 166 and 167 by choosing the efficient nondoped green TADF material 142 as the emitting core. Using a methylene group as the linkage can effectively disrupt the conjugation between the peripheral Cz-based dendrons and the emitter core.…”