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

Abstract

Nondoped organic light-emitting diodes (OLEDs) have drawn immense attention due to their merits of process simplicity, reduced fabrication cost, etc. To realize high-performance nondoped OLEDs, all electrogenerated excitons should be...

Thermally activated delayed fluorescence dendrimers achieving 20% external quantum efficiency for solution-processed OLEDs

“…As shown in Scheme S1 (ESI †), the target compounds for tBuTCz-DPyM and MeOTCz-DPyM were prepared via the Ullmann C-N coupling reaction of DPyM with tBuTCz or MeOTCz, respectively. 40,41 The chemical structures of the two dendrimers were confirmed using 1 H NMR and 13 C NMR and high-resolution MS.…”

“…Anhydrous toluene was refluxed with sodium and anhydrous dichloromethane was refluxed with calcium hydride, followed by fresh distillation before use. 1 H NMR and 13 C NMR spectra were recorded in CDCl 3 with tetramethylsilane (TMS) as the internal standard using a Bruker Avance 600 MHz spectrometer. HRMS (Q-TOF) spectra were obtained using an Impact II spectrometer (Bruker Daltonics Inc.).…”

“…At this stage, great progress has been made with solution-processed OLEDs. [9][10][11][12][13][14][15][16] Nonetheless, the performance of solution-processed OLEDs still needs to be greatly improved, and comparison with that of vacuumdeposited OLEDs is difficult. In recent years, as a thirdgeneration light-emitting material in OLEDs, based on their advantages of being heavy metal-free, low cost and achieving a 100% internal quantum efficiency (IQE) through efficient reverse intersystem crossing (RISC) procedures, thermally activated delayed fluorescence (TADF) emitters have received great attention.…”

Tandem rigidification and π-extension as a key tool for the development of a narrow linewidth yellow hyperfluorescent OLED system

“…1 Fluorescent (1st generation) and phosphorescent (2nd generation) OLED emitters, 2,3 which have been commercially available for 15 years, have suffered from insufficient colour purity, poor efficiencies, and lifetimes, as well as high manufacturing costs. Subsequently, a 3rd generation of metal-free, thermally activated delayed uorescent (TADF) [4][5][6][7] organic materials has been intensively explored within the last few years as promising candidates for commercial applications. The key feature of the operating mechanism of 3rd generation emitters is reverse intersystem crossing (rISC), in which the electron transfer proceeds from a triplet state to a singlet state.…”

Tandem rigidification and π-extension as a key tool for the development of a narrow linewidth yellow hyperfluorescent OLED system.

“…1 The fluorescent (1 st generation) and phosphorescent (2 nd generation) OLED emitters, 2,3 which have been commercially available for 15 years, have suffered insufficient colour purity, poor efficiencies, and lifetimes, as well as high manufacturing costs. Subsequently, a 3 rd generation of metal-free, thermally activated delayed fluorescent (TADF) [4][5][6][7] organic materials have been intensively explored within the last few years as promising candidates for commercial applications. The key feature of the operating mechanism of 3 rd generation emitters is reverse intersystem crossing (rISC), in which the electron transfer proceeds from a triplet state to a singlet state.…”