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Top-emitting microcavity OLEDs (TEOLEDs) exhibit excellent color purity but suffer from severe angular color shifts. To overcome this, we introduce a nanotextured light modulation strategy using a nanoporous film (NPF) and an index-matched optically clear resin (OCR) for encapsulation. The nanotextured NPF enhances light outcoupling while suppressing cavity-induced angular dependence. As a result, the external quantum efficiency (EQE) is enhanced by 370% (from 8.5 to 31.6%), and angular color shift (Δu′v′) is reduced by 65.2% (from 0.046 to 0.016). By introducing a nanostructure-based light modulation technology, we have achieved a breakthrough in microcavity OLED performance, simultaneously improving both outcoupling and angular stability. Applied to flexible TEOLEDs, the device exhibits stable optical and mechanical performance under bending. This scalable and effective light modulation design enables highly efficient and color-stable flexible OLED displays for next-generation wearable applications.

The realization of highly operationally stable blue organic light‐emitting diodes (OLEDs) is a challenge in both academia and industry. This paper describes the development of anthracene–dibenzofuran host materials, 2‐(10‐(naphthalen‐1‐yl)anthracen‐9‐yl)naphtho[2,3‐b]benzofuran (Host 1) and 2‐(10‐([1,1′‐biphenyl]‐2‐yl)anthracen‐9‐yl)naphtho[2,3‐b]benzofuran (Host 2), namely for use in the emissive layer of an OLED stack. A multiple‐resonance thermally activated delayed serves as the blue fluorescence emitter and exhibits an initial luminance of 1000 cd m−2 and long operational stability (i.e., time to decay to 90% of initial luminance) of 249 h. Furthermore, a deep‐blue OLED with an optimized top‐emitting architecture with a high current efficiency of 154.3 cd A−1, is fabricated and calibrated to a Commission International de l’Éclairage y chromaticity coordinate of 0.048. Moreover, the emission spectrum of this OLED has a narrowband peak at 476 nm with a full width at half maximum (FWHM) of 16 nm. This work provides valuable insights into the design of anthracene‐based host materials and highlights the importance of host optimization in improving the operational stability of OLEDs. This paper explores the demonstration of highly stable blue organic light‐emitting diodes (OLEDs) using novel anthracene–based host materials. Integrating a multiple‐resonance emitter, the OLEDs exhibit exceptional long‐operational stability (LT90 = 249 h). Additionally, a top‐emitting deep‐blue OLED with superior current efficiency and precise emission characteristics underscores the significance of host material optimization for enhancing OLED stability.

Intrinsic nonuniformity in the polycrystalline-silicon backplane transistors of active matrix organic light-emitting diode displays severely limits display size. Organic semiconductors might provide an alternative, but their mobility remains too low to be useful in the conventional thin-film transistor design. Here we demonstrate an organic channel light-emitting transistor operating at low voltage, with low power dissipation, and high aperture ratio, in the three primary colors. The high level of performance is enabled by a single-wall carbon nanotube network source electrode that permits integration of the drive transistor and the light emitter into an efficient single stacked device. The performance demonstrated is comparable to that of polycrystalline-silicon backplane transistor-driven display pixels.

Organic Light Emitting Diodes (OLEDs) are emerging as promising alternatives to conventional lighting and display technologies due to their unique properties and potential energy efficiency. This study conducts a comprehensive investigation into OLED materials, focusing on their optical, electrical, and structural characteristics. Through experimental analysis and theoretical modeling, the study delves into the performance and behaviour of various OLED materials, including organic semiconductors, charge transport layers, and emissive materials. Critical aspects such as charge carrier mobility, exciton formation, and device stability are examined to understand the mechanisms governing OLED operation. The findings offer valuable insights into optimizing OLED devices for applications ranging from consumer electronics to lighting and signage. This research contributes fundamental knowledge and practical guidelines for material selection, device fabrication, and performance assessment, thereby advancing OLED technology. The insights provided pave the way for future innovations in OLED materials and device design, potentially leading to improvements in efficiency, brightness, and longevity.

We present the development of multifunctional blue-emission organic light-emitting diodes (OLEDs) using TADF-exciplex materials. These OLEDs exhibit sensitivity to external stimuli and achieve a maximum external quantum efficiency (EQE) of 11.6% through partly liquid processing. This technique allows for large-scale production on arbitrary geometries. The potential multifunctionality of the devices arises from their response to low external magnetic fields (up to 100 mT) with an efficiency up to 2.5% for magnetoconductance, while maximum magneto-electroluminescence effects of 4.1% were detected. We investigated novel aspects, including the utilization of two organic materials without further doping and the investigation of the impact of 2,2ʹ,2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1- H -benzimidazole) (TPBi) processing in liquid and vapor form. The insights gained provide a fundamental understanding regarding the applicability of exciplex (EX) materials for fully solution-processed OLEDs through a deliberate omission of doping. Our work represents a significant advancement on the path towards multifunctional OLED technology, with potential applications in cost-efficient, scalable organic full-color displays and advanced sensing system.

Organic light emitting diode (OLED) technology continues to make strides, particularly in display technology, with costs decreasing and consumer demand growing. Advances are also seen in OLED solid state lighting (SSL) though broad utilization of this technology is lagging. This situation has prompted extensive R&D to achieve high-efficiency SSL devices at cost-effective fabrication. Here we review the advances and challenges in enhancing forward light outcoupling from OLEDs. Light outcoupling from conventional bottom-emitting OLEDs (through a transparent anode) is typically ∼20%, largely due to external losses, i.e., substrate waveguide modes, internal waveguide modes between the metal cathode and the anode/substrate interface, and surface plasmon-polariton modes at the metal cathode/organic interface. We address these major photon loss paths, presenting various extraction approaches. Some approaches are devoid of light extraction structures; they include replacing the commonly used ITO anode, manipulating the refractive index of the substrate and/or organic layers, and evaluating emitters with preferential horizontal transition dipoles. Other approaches include the use of enhancing structures such as microlens arrays, scattering layers and patterned substrates, as well as substrates with various buried structures that are planarized by high index layers. A maximal external quantum efficiency as high as 78% was reported for white planarized OLEDs with a hemispherical lens to extract the substrate mode. Light outcoupling from OLEDs on flexible substrates is also addressed, as the latter become of increasing interest in foldable displays and decorative lighting, with plastic substrates also being evaluated for biomedical, wearable, and automotive applications.

White organic light-emitting diodes (OLEDs) offer a promising solution for next-generation lighting technologies and their ability to emit white light through various mechanisms make them an attractive option for illumination and display applications. Here, we design and prepare a series of N,N-difluorenevinylaniline-based small molecules and polymer, and realize white OLEDs based on these luminescent materials with combined blue monomer emission and orange electromer emission upon electronic excitation in the solution-processed devices. Impressively, the single-component nonconjugated polymer exhibits the best device performance, because the nonconjugated structure favors good solubility of the polymers, while the conjugated starburst unit functions as highly luminescent fluorophore in both single molecular and aggregated structures for the blue and orange emissions, respectively. Specifically, the non-doped solution-processed OLEDs achieve warm white electroluminescence with a maximum luminance of 1806 cd/m2 and a maximum external quantum efficiency of 2.63%. And, the OLEDs based on the monomer also exhibit white electroluminescence with Commission Internationale de L’Eclairage coordinates of (0.30, 0.32). These results highlight a promising strategy for the material design and preparation of single-component nonconjugated polymers with rich emissive behaviors in solid states towards efficient and solution-processable white OLEDs.

Spin-flip in purely organic molecular systems is often described as a forbidden process; however, it is commonly observed and utilized to harvest triplet excitons in a wide variety of organic material-based applications. Although the initial and final electronic states of spin-flip between the lowest singlet and lowest triplet excited state are self-evident, the exact process and the role of intermediate states through which spin-flip occurs are still far from being comprehensively determined. Here, via experimental photo-physical investigations in solution combined with first-principles quantum-mechanical calculations, we show that efficient spin-flip in multiple donor–acceptor charge-transfer-type organic molecular systems involves the critical role of an intermediate triplet excited state that corresponds to a partial molecular structure of the system. Our proposed mechanism unifies the understanding of the intersystem crossing mechanism in a wide variety of charge-transfer-type molecular systems, opening the way to greater control over spin-flip rates.

Organic light-emitting diodes (OLEDs) offer lucrative advantages in screening and illuminating technologies, including high luminance, design flexibility and energy efficiency. However, commercial adoption is hindered by challenges like device degradation and efficiency roll-off, especially under thermal and electrical stress. This review focuses on the application of lanthanide-based materials in OLEDs, emphasizing their unique photophysical properties and roles as emissive dopants and buffer layers. Lanthanide complexes such as europium(III), samarium(III), terbium(III) and cerium(III) possess unique photophysical properties that enhance exciton confinement, reduce polaron–exciton annihilation and improve radiative efficiency. Ligand systems, including β-diketonates, phenanthroline derivatives, scorpionate frameworks and boron-containing ligands, further support high triplet-energy transfer, improved solubility and efficient charge balance within host–dopant architectures. Europium-based emitters demonstrate reduced roll-off and improved luminance. Additionally, cerium(III) complexes show ultrafast excited-state lifetimes and near-unity quantum yields. Metal alloys incorporating ytterbium and its oxides act as superior buffer layers in cathodes that can inhibit the penetration of moisture and oxygen, enhancing both transparency and lifetime. Yb-based cathodes and interlayers, especially in combinations like Yb/Ag or LiF/Yb/Ag, enable efficient electron injection and mitigate degradation through improved stability. These innovations collectively address core issues in OLED performance, laying the foundation for highly durable, high-brightness and flexible optoelectronic devices.

In academic research, OLEDs have exhibited rapid evolution thanks to the development of innovative materials, new device architectures, and optimized fabrication methods, achieving high performance in recent years. The numerous advantages that increasingly distinguish them from traditional light sources, such as a large and customizable emission area, color tunability, flexibility, and transparency, have positioned them as a promising candidate for various applications in the lighting market, including the residential, automotive, industrial, and agricultural sectors. However, despite these promising attributes, the widespread industrial production of OLEDs encounters significant challenges. Key considerations center around efficiency and lifetime. In the present review, after introducing the theoretical basis of OLEDs and summarizing the main performance developments in the industrial field, three crucial aspects enabling OLEDs to establish a competitive advantage in terms of performance and versatility are critically discussed: the quality and stability of the emitted light, with a specific focus on white light and its tunability; the transparency of both electrodes for the development of fully transparent and integrable devices; and the uniformity of emission over a large area.