High‐Efficiency Ultraviolet Electroluminescence from Multi‐Resonance Phosphine Oxide Polycyclic Aromatics

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(5)

Опубликована: Дек. 7, 2023

Abstract Efficient ultraviolet (UV) electroluminescent materials remain a great challenge, since short peak wavelength <400 nm and narrow full width at half maximum (FWHM) <50 are simultaneously required. In this sense, multi‐resonance (MR) thermally activated delayed fluorescence (TADF) emitters featuring narrow‐band emissions hold the promise for UV applications. Herein, novel MR‐TADF skeleton carbazole‐phosphine oxide (P=O) fused aromatics is developed to construct first two MR named CzP2PO tBCzP2PO . addition synergistic resonance effects of P=O N atom, sp 3 ‐hybrid P atom renders curved polycyclic planes , giving rise their narrowband with wavelengths <390 FWHM<35 nm. Besides configuration quasi‐planarization radiation enhancement quenching suppression, moiety further enhances singlet‐triplet coupling facilitate reverse intersystem crossing, resulting in state‐of‐the‐art photoluminescence quantum yield 62 % doped films. As consequence, endowed its organic light‐emitting diodes 382 FWHM 32 nm, especially record‐high external efficiency (EQE) 15.1 among all kinds devices. Our results demonstrate potential based practical applications including optoelectronics, biology medicine science.

Язык: Английский

---

Recent Progress of Thermally Activated Delayed Fluorescent Materials with Narrowband Red, Green, and Blue (RGB) Emission

ACS Materials Letters, Год журнала: 2024, Номер 6(5), С. 1746 - 1768

Опубликована: Апрель 2, 2024

Narrowband thermally activated delayed fluorescence (TADF) materials have received widespread attention due to their promising applications in organic light-emitting diodes with high-definition displays. Great efforts been done achieve full-color narrowband emissions donor–acceptor (D–A) and multiple-resonance (MR) TADF materials. In comparison the D–A materials, MR-based basically showed smaller full width at half-maximum (fwhm) of spectra owing inherent structural vibration inhibition electronic transition characteristics. Herein, review summarizes current research progress on both MR blue, green red emission regions fwhm less than 70 nm concentrating molecular design strategies, photophysical properties corresponding device performance, proposes some possible future topic. This aims give physical insight structure–property relationship such offer guidance for further developing provide a structured database platform high-throughput or machine learning research.

Язык: Английский

---

Peripheral Selenium Modification of Multi‐Resonance Thermally Activated Delayed Fluorescence Molecules for High‐Performance Blue Organic Light‐Emitting Diodes

Advanced Optical Materials, Год журнала: 2024, Номер 12(11)

Опубликована: Фев. 28, 2024

Abstract Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) molecules have attracted much attention in the academia owing to their unique photoelectrical properties. However, MR‐TADF emitters usually show slow reverse intersystem crossing (RISC) rate, resulting high efficiency roll‐off of organic light‐emitting diodes (OLEDs) and seriously limiting further development. Here, a peripheral selenium (Se) modification is presented for promote RISC process while keeping narrowband emission high‐performance blue OLEDs. Compared parent (NBN t BuNBN), SeNBN Se BuNBN exhibited narrower full‐width at half maximum (FWHM) value 23 nm more obvious properties with up 86%, shorter lifetime 2.4 µs as well faster rate 3.34×10 5 s −1 . Therefore, OLEDs based on these two modified are achieved external quantum (EQE) 25.5% extremely suppressed roll‐offs 3.9% 100 cd m −2 24.4% 1000 This work demonstrated that introduction atom can achieve semiconductors both fast constant optoelectronic devices.

Язык: Английский

---

Multiple‐resonance thermally activated delayed emitters through multiple peripheral modulation to enable efficient blue OLEDs at high doping levels

Aggregate, Год журнала: 2024, Номер 5(5)

Опубликована: Май 13, 2024

Abstract Organic light‐emitting diodes (OLEDs) based on multiple resonance‐thermally activated delayed fluorescence (MR‐TADF) have the advantages of high exciton utilization and excellent color purity. However, large conjugated planarity general MR‐TADF emitters makes them easily aggregate in form π–π stacking, resulting aggregation‐caused quenching (ACQ) formation excimers, which reduce efficiency To address these issues, shielding units can be incorporated to prevent interchromophore interactions, whereas majority reported molecules are limited blue‐green light emissions. This work proposes a strategy incorporating steric hindrance groups at different sites B/N core suppress interactions between chromophore, contributing blue with photo‐luminance quantum yields (PLQYs ≥ 95%) narrow full width half maximum (FWHM), importantly, great suppression ACQ effect. Therefore, OLEDs achieve external efficiencies up 34.3% purity FWHM about 27 nm CIE around (0.12, 0.15), even doping concentration 20 wt%.

Язык: Английский

---

Quantitative prediction of rate constants and its application to organic emitters

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Июнь 3, 2024

Many phenomena in nature consist of multiple elementary processes. If we can predict all the rate constants respective processes quantitatively, comprehensively and understand various phenomena. Here, report that it is possible to quantitatively related quantum yields without conducting experiments, using multiple-resonance thermally activated delayed fluorescence (MR-TADF) as an example. MR-TADFs are excellent emitters because its narrow emission, high luminescence efficiency, chemical stability, but they have one drawback: slow reverse intersystem crossing (RISC), leading efficiency roll-off reduced device lifetime. show a calculation method for obtaining yields. This study reveals strategy improve RISC compromising other important factors: radiative decay constants, photoluminescence yields, emission linewidths. Our be applied wide range research fields, providing comprehensive understanding mechanism including time evolution excitons.

Язык: Английский

---

Efficient Ultra‐Narrowband OLEDs Based on Carbazole‐Fused Dual‐Boron Embedded Multi‐Resonance Thermally Activated Delayed Fluorescence Materials

Advanced Optical Materials, Год журнала: 2024, Номер 12(15)

Опубликована: Янв. 2, 2024

Abstract The development of efficient multi‐resonance thermally activated delayed fluorescence (MR‐TADF) materials with ultra‐narrowband emission presents an ongoing challenge. In this work, a carbazole‐fused dual‐boron embedded MR‐TADF framework is proposed, achieving three emitters, CFDBO, CFDBA, and CFDBCz, via one‐shot borylation very high yields over 70%. emitters display blue peaks ranging from 452 to 479 nm small full width at half maximum (FWHM) values only 16–18 in dilute toluene solutions. Furthermore, the organic light‐emitting diode (OLED) incorporating CFDBO exhibits pure‐blue peak 460 Commission International de l'Eclairage coordinates (0.14, 0.12). Meanwhile, OLEDs CFDBA/CFDBCz demonstrate remarkable performances external quantum efficiencies 30.9%/32.4% exceptionally slender FWHM 21/22 nm, representing outstanding among reported materials.

Язык: Английский

---

Phosphine oxide balanced charge transfer hybridization in multi-resonance emitters: towards ∼40% external quantum efficiency and preserved color purity

Chemical Engineering Journal, Год журнала: 2024, Номер 489, С. 151517 - 151517

Опубликована: Апрель 22, 2024

Язык: Английский

---

Recent Advances in Narrow Emission Bandwidth Materials for Application in Organic Light‐Emitting Diodes

Advanced Optical Materials, Год журнала: 2025, Номер unknown

Опубликована: Фев. 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.

Язык: Английский

---

Color-tunable circularly polarized electroluminescence from a helical chiral multiple resonance emitter with B-N bonds

Science China Chemistry, Год журнала: 2023, Номер 66(9), С. 2612 - 2620

Опубликована: Авг. 17, 2023

Язык: Английский

---

Boron- and Nitrogen-Embedded Polycyclic Arenes as an Emerging Class of Organic Semiconductors

Chemistry of Materials, Год журнала: 2023, Номер 35(24), С. 10277 - 10294

Опубликована: Дек. 11, 2023

The development of novel organic semiconductors has continuously promoted the field optoelectronics. During past decade, boron- and nitrogen-embedded (BN-embedded) polycyclic arenes have attracted considerable attention, enriching structural diversity providing a broad space for tuning their optoelectronic properties. application BN-embedded conjugated materials in different devices achieved excellent performance, e.g., high charge-carrier mobilities (μ > 1.0 cm2 V–1 s–1) field-effect transistors (OFETs), ultrapure electroluminescence (full-width at half-maximum ≤ 18 nm) light-emitting diodes (OLEDs), power conversion efficiency (PCE 19%) photovoltaics (OPVs). These advances make promising class high-performance semiconductors. Nevertheless, inherent relationship between BN-doping modes properties never been systematically discussed. In this Perspective, we aim to present an overview unique family by selecting representative examples. We will first outline characters modes, discuss effect on electronic structures arenes, finally showcase advanced applications emerging devices. hope bring together communities further promote semiconductor materials.

Язык: Английский

---