A meta-linkage strategy towards high-performance hosts for efficient blue thermally activated delayed fluorescence OLEDs

Abstract

The development of high-performance host materials for blue thermally activated delayed fluorescence (TADF) emitters is crucial to realizing efficient blue organic light-emitting diodes (OLEDs). Herein, two star-shaped host materials, tris(3-(diphenylphosphanyl...

Voltage-Dependent Emission Varying from Blue to Orange–Red from a Nondoped Organic Light-Emitting Diode with a Single Emitter

“…In order to examine the electroluminescent (EL) performance of the emitters, we fabricated nondoped and 20 wt%-doped OLEDs, the configurations of which [ 22 , 23 ] are depicted in Figure 5 a. The energy level of PDPC was determined by CV analysis, the result of which is plotted in Figure S10b , and the bandgap was calculated from a Tauc plot that is shown in Figure S10c .…”

Weak-conjugation linked donor–acceptor emitters for efficient near-ultraviolet organic light-emitting diodes with narrowed full width at half maximum

“…17–24 In addition, the links between the donor and acceptor often play a key role for emitters. 25–34 A link with a conjugation or nonconjugation method between the donor and acceptor, such as ortho -, meta -, and para -positions in a benzene ring, can finely modulate the electronic states and the emission wavelength. Compared to the para -position conjugation, meta -position conjugation often provides blue-shifted emission due to the weaker D–A interaction, while the ortho -position conjugation can effectively alter the electronic structure by the twisting effect, especially for molecules with large D and A groups.…”

Efficient yellow and red thermally activated delayed fluorescence materials based on a quinoxaline-derived electron-acceptor

“…Thermally activated delayed fluorescence materials have attracted intensive attention due to their potential to realize 100% internal quantum efficiency (IQE) in organic light-emitting diodes (OLEDs). 1–8 Although numerous highly efficient green and blue TADF emitters have been reported to date, high-efficiency red TADF materials are still rare. 9–12 Firstly, a small energy gap (Δ E ST ) between the lowest singlet excited (S 1 ) state and the lowest triplet excited (T 1 ) state is indispensable for realizing a fast reverse intersystem crossing (RISC) process.…”