Steric Rooted Multi‐Resonant Thermally Activated Delayed Fluorescent Emitters for Pure Blue Organic Light Emitting Diodes with Ultralow Efficiency Roll‐Off DOI
Ezhakudiyan Ravindran,

Ho Eon Baek,

Hee Won Son

et al.

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(35)

Published: May 14, 2023

Abstract Multi‐resonant thermally activated delayed fluorescent ( MR‐TADF ) materials are blooming for high‐resolution organic light‐emitting diodes (OLEDs). However, boron/nitrogen (B/N)‐integrated emitters suffer severe efficiency roll‐off from their strong inter‐molecular π – interactions. Herein, versatile narrowband pure blue mono‐ mx ‐CzDABNA and tri‐ demonstrated featuring a ring‐fused extended ‐skeleton: classic steric hindrance rigidity accessed by integrating with meta ‐xylene rotors. shows (FWHM, 26 nm) emission λ max , 462 substantial hypsochromic shift (12 while maintaining characteristics. The key solid‐state analyses conclude that they conceivably suppress the non‐radiative energy loss, thus improving photoluminescence quantum yield (PLQY > 90%) rate of reverse intersystem crossing (RISC) k RISC ≈2.85 × 10 5 s −1 ). integration tri meta‐xylene significantly leads to an enhanced horizontal dipole ratio (HDR) 65% 85%. Hyperfluorescent‐OLEDs fabricated using designed as terminal emitter, achieving 34 electroluminescence 472 maximum external (EQE 26.97% magnificently suppressed (7.8%) at 1000 cd m −2 . So, it is believed regulation internal efficiencies high color purity can amplify route through new synthetic approaches.

Language: Английский

Blue Multiple‐Resonance Thermally Activated Delayed Fluorescence Materials DOI Open Access
Boyao Cui, Jianqiao Zhou,

Chunbo Duan

et al.

Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 8, 2025

Abstract Organic light‐emitting diodes (OLEDs) exhibit significant advantages in the fields of ultra‐high‐definition (UHD) displays and wearable devices. However, developing low‐cost, high‐efficiency, high‐purity blue emission materials remains a challenge for academia industry. While thermally activated delayed fluorescence (TADF) meet low‐cost manufacturing needs achieve 100% internal quantum efficiency, their charge‐transfer excited states lead to broad spectra that don't BT.2020 standard. Fortunately, multiple resonance (MR) strategy offers an effective solution creating TADF with high color purity. Through careful structural design precise tuning state energy levels, MR‐TADF can easily full‐width at half‐maximum (FWHM) less than 30 nm. Nevertheless, it still faces challenges, such as severe aggregation‐induced quenching efficiency roll‐off. Herein, this work overviews recent progress devices, introduce representative molecular strategies aimed suppressing concentration quenching, enhancing reverse intersystem crossing rates, achieving deep emission, which will aid future endeavors develop more efficient, stable devices suitable UHD display applications.

Language: Английский

Citations

1
Recent Advances in Narrow Emission Bandwidth Materials for Application in Organic Light‐Emitting Diodes DOI Open Access
Jia-Min Kang, Dong Jin Shin, Jun Yeob Lee

et al.

Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 21, 2025

Abstract The preparation of narrow emission bandwidth materials is crucial for the development advanced organic light‐emitting diodes (OLEDs). In this review article, state‐of‐the‐art methodologies used emitters with high color purity are summarized, and favorable design strategies rationally organized. Currently OLEDs have some issues, such as device stabilization that must be resolved, should also considered. Given recent exponential growth in number types narrowband emissive organometallic complexes exhibiting multiple‐resonance thermally activated delayed fluorescence metal‐to‐ligand charge transfer characteristics, there an urgent need to establish key technology descriptors purity. review, developments boron, fused indolocarbazole, carbonyl, phosphine oxide, exhibit spectra described, future directions advance performance devices suggested.

Language: Английский

Citations

1
Remarkable White Circularly Polarized Electroluminescence Based on Chiral Co‐assembled Helix Nanofiber Emitters DOI
Yu Zhang, Yupeng Li, Yiwu Quan

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(1)

Published: Nov. 4, 2022

White circularly polarized organic light-emitting diodes (CP-WOLEDs) are of great significance in potential lighting sources and full-color 3D displays. However, High-performance white CP-EL almost unexplored. We have constructed devices based on chiral co-assemblies by using three achiral conjugated pyrene-based dyes (BP, w-WP c-WP) doped with binaphthyl-based enantiomers (S-/R-M) as the EMLs through an intermolecular chirality induction mechanism. (S-/R-M)0.2 -(c-WP)0.8 films exhibit regular helix nanofibers under annealing treatment emit strong CPL. Significantly, remarkable CP-WOLEDs were achieved |gEL | values high 6.2×10-2 excellent CRI 98 at CIE coordinates (0.33, 0.33). These highest gEL reported to date. This is first achievement co-assembled nanofiber emitters, provides a valuable strategy which develop for future practical applications.

Language: Английский

Citations

35
Thermally activated delayed fluorescence materials for organic light-emitting diodes DOI
Xiaoning Li,

Shiyao Fu,

Yujun Xie

et al.

Reports on Progress in Physics, Journal Year: 2023, Volume and Issue: 86(9), P. 096501 - 096501

Published: June 22, 2023

Abstract Recently, the remarkable advances in thermally activated delayed fluorescence (TADF) materials have attracted much attention due to their 100% exciton utilization efficiency organic light-emitting diodes (OLEDs). Although commercialization of TADF is at an early stage, they exhibit enormous potential for next-generation OLEDs comparable electroluminescence performance metal phosphorescent complex counterparts, but without presence precious elements. This review summarizes different types small molecules with various photophysical properties and state-of-the-art molecular design strategies. Furthermore, device engineering discussed, emerging optoelectronic applications, such as electrochemical cells, lasing, scintillators, are introduced. It anticipated that this can clarify efficient emitters point out direction future development.

Language: Английский

Citations

22
Steric Rooted Multi‐Resonant Thermally Activated Delayed Fluorescent Emitters for Pure Blue Organic Light Emitting Diodes with Ultralow Efficiency Roll‐Off DOI
Ezhakudiyan Ravindran,

Ho Eon Baek,

Hee Won Son

et al.

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(35)

Published: May 14, 2023

Abstract Multi‐resonant thermally activated delayed fluorescent ( MR‐TADF ) materials are blooming for high‐resolution organic light‐emitting diodes (OLEDs). However, boron/nitrogen (B/N)‐integrated emitters suffer severe efficiency roll‐off from their strong inter‐molecular π – interactions. Herein, versatile narrowband pure blue mono‐ mx ‐CzDABNA and tri‐ demonstrated featuring a ring‐fused extended ‐skeleton: classic steric hindrance rigidity accessed by integrating with meta ‐xylene rotors. shows (FWHM, 26 nm) emission λ max , 462 substantial hypsochromic shift (12 while maintaining characteristics. The key solid‐state analyses conclude that they conceivably suppress the non‐radiative energy loss, thus improving photoluminescence quantum yield (PLQY > 90%) rate of reverse intersystem crossing (RISC) k RISC ≈2.85 × 10 5 s −1 ). integration tri meta‐xylene significantly leads to an enhanced horizontal dipole ratio (HDR) 65% 85%. Hyperfluorescent‐OLEDs fabricated using designed as terminal emitter, achieving 34 electroluminescence 472 maximum external (EQE 26.97% magnificently suppressed (7.8%) at 1000 cd m −2 . So, it is believed regulation internal efficiencies high color purity can amplify route through new synthetic approaches.

Language: Английский

Citations

18