Themed collection Perspective on the technologies of OLEDs

This review highlights the importance of developing color-tunable TADF, CPL TADF and MR-TADF emitters and their molecular strategies to achieve exceptional photophysical characteristics, which are crucial for advancing OLED technology.

This review summarizes recent advances in solution-processable small-molecule TADF emitters, categorized by molecular skeletons, with the most efficient representative of each class highlighted.

A deep-blue material based on a crossed long-short axis strategy and a large conjugate core, which enables high-lying reverse intersystem crossing and achieves an efficiency of 7.46% at 420 nm with CIE coordinates meeting the BT.2020 standard.

Efficient non-doped bluish-green to green thermally activated delayed fluorescence (TADF) OLEDs are fabricated with two TADF emitters, namely HDT1 and 36Me-HDT1, achieving maximum external quantum efficiencies of 16.5% and 21.0%, respectively.

We propose a machine learning and generative approach for circularly polarized TADF. A robust model finds key g_lum features, and a VAE generates candidates with high g_lum and good synthetic accessibility for chiral optoelectronics.

MesCzBN achieves EQE of 38.6%, and FWHM of 28 nm via mesitylene shielding, enhancing horizontal orientation and surpassing tCzBN performance.

A quasiplanar deep-blue thermally activated delayed fluorescence emitter was developed based on a dual-locked strategy, achieving a maximum external quantum efficiency (EQE_max) exceeding 10% at 444 nm and excellent CIE coordinates of (0.15, 0.08).

By hybridizing the SRCT and LRCT characteristics, a sensitizer-free OLED based on BNAP demonstrated remarkable EL performance with an EQE_max of 36.1%, EQE of 32.8% at 100 cd m⁻², EL peak at 512 nm, FWHM of 36 nm, and CIE coordinates of (0.17, 0.68).

Four multi-resonant fluorescent materials based on a N/B–C framework show narrowband emission from green to red with high photoluminescence efficiencies. While their organic light-emitting diodes exhibit external quantum efficiencies of up to 23%.

Tetrahydrocarbazole donors enable sky-blue MR-TADF emitters with narrowband emission and efficient TADF, expanding design strategies for color-pure materials.

Herein, carbazole integrated phenanthroimidazole-based HLCT emitters have been developed for efficient deep-blue OLEDs. The structure–function relationships were established.

Demonstrating the potential of exciplex-based devices for both OLED and UV photodetector applications by leveraging the concept of spontaneous orientational polarization.

We report on the synthesis of two novel nanographenes, syn- and anti-dinaphthopentacene. This small variation in structure leads to stark differences in structural and photophysical properties as well as OLED device efficiency.

A novel narrowband multi-resonance emitter obtained by incorporating B–N covalent bonds and extending π-conjugation via a simplified lithium-free one-pot borylation reaction achieved a redshifted sky-blue emission at 484 nm with a FWHM of 19 nm.

Molecules with an inverted singlet–triplet gap violate Hund's rule and offer promising applications in photoactive materials.

Using the blue TADF molecule (PytBuCz-XT) containing a xanthone acceptor as an emitter or a sensitizer in OLEDs provides longer operational lifetimes than the control molecule (PytBuCz-XT) containing a triphenyltriazine acceptor.

We thoroughly assess here the recently developed (SOS1-)PBE-DH-INVEST double-hybrid density functionals using the NAH159 dataset, in the search of a robuts and accurate method for S₁–T₁ gaps.

The physical interactions between the host and emitter in solution-processed organic light-emitting diodes (OLEDs) significantly influence device performance.

Ir(III) carbene complexes bearing bulky 2-xylenyl substituents were synthesized and utilized in OLED fabrication. The f-ct9ax-based hyper-OLED exhibited narrowband blue emission with a maximum EQE of 31.9%, and an EQE of 20.9% at 1000 cd m⁻².

2PhTPA demonstrates improved performance by weakening the TSCT. This design reduces non-radiative decay and improves radiative efficiency, emphasizing the importance of optimizing TSCT properties in TADF emitter design for higher OLED performance.