Commission Internationale Research Articles

International models of accreditation and certification for hospitals with a focus on nursing: a scoping review

Abstract Background Quality assurance in hospitals is essential for ensuring patient safety, quality of care and efficiency. The nursing profession is a key contributor to healthcare quality, yet, a comprehensive overview and comparison of the role and scope of nursing as part of accreditation and certification schemes has been lacking. The aim was to identify if and to what extent international accreditation or certification schemes focus on nursing, and to compare their conceptual models and outcome indicators. Methods A scoping review was conducted. A search strategy was developed together with a librarian and carried out in January 2024 in Medline, CINAHL, Web of Science Core Collection, Cochrane Reviews and Google Scholar. Additionally, authoritative websites of accreditation/certification holders were searched. Inclusion criteria were studies on international accreditation or certification schemes for hospital settings with relevance to nursing published in English or German. Screening and data analysis adhered to the Joanna Briggs Institute’s methodology, with reporting following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guideline (PRISMA-ScR). Results The search identified 17.315 records. After removing duplicates and screening of titles/abstracts, 336 full-texts remained. A total of 124 studies were included, identifying seven international accreditation/certification schemes: European Foundation for Quality Management, Evaluation and Quality Improvement Program, International Organization for Standardization 9001, Joint Commission International®, Magnet Recognition Program®, Pathway to Excellence® Program, Qmentum®. The different schemes ranged from nursing-specific to having no specific focus on, but relevance for, nursing and varied in their topics, focus on structure, process and outcome quality and structure and content of requirements. Additionally, outcome indicators varied, with differences in the extent to which indicators were nurse-sensitive, compulsoriness of data collection, and use of external benchmarking. Conclusions The seven international schemes show large conceptual variations as to their focus on nursing and differences in the degree of nurse-specific outcome indicators. Hospital and nursing managers, policymakers, patients and the public need to understand the content and outcome dimensions of the schemes when making decisions or assessing hospital quality data.

Simple‐Structure and Anti‐Quenching Deep‐Blue Multi‐Resonance TADF Emitters Enable High‐Efficiency OLEDs with BT.2020 Blue Gamut

AbstractDeveloping highly efficient pure‐blue organic light‐emitting diodes (OLEDs) that meet the stringent BT.2020 standard by using multi‐resonance thermally activated delayed fluorescence (MR‐TADF) materials has long been a formidable challenge. In this study, a strategy is demonstrated for high‐performance blue MR‐TADF emitters by gradually decorating the MR framework with alkyl groups, and subsequently introducing a diarylamino group at the para‐position of boron atom. The proof‐of‐concept molecule, IPrBN‐mCP, exhibits a narrowband deep‐blue emission peaking at 452 nm, with a very narrow full‐width at half maximum (FWHM) of 19 nm in solution, and a remarkably high photoluminescence quantum yield (PLQY) approaching unity in doped films. As a result, OLEDs based on IPrBN‐mCP achieve not only a high maximum external quantum efficiency (EQEmax) of 33.4% but also ultrapure blue emission with a Commission Internationale de L'Eclairage (CIE) y value of 0.046, fully satisfying the BT.2020 blue standard. This represents the first OLED example fully meeting the rigorous color requirements of the BT.2020 blue standard while simultaneously achieving an EQE exceeding 30%.

Solution Processed Bilayer Metal Halide White Light Emitting Diodes.

Metal halide perovskites and perovskite-related organic metal halide hybrids (OMHHs) have recently emerged as a new class of luminescent materials for light emitting diodes (LEDs), owing to their unique and remarkable properties, including near-unity photoluminescence quantum efficiencies, highly tunable emission colors, and low temperature solution processing. While substantial progress has been made in developing monochromatic LEDs with electroluminescence across blue, green, red, and near-infrared regions, achieving highly efficient and stable white electroluminescence from a single LED remains a challenging and under-explored area. Here, a facile approach to generating white electroluminescence is reported by combining narrow sky-blue emission from metal halide perovskites and broadband orange/red emission from zero-dimensional (0D) OMHHs. For the proof of concept, utilizing TPPcarz+ passivated two-dimensional (2D) CsPbBr3 nanoplatelets (NPLs) as sky blue emitter and 0D TPPcarzSbBr4 as orange/red emitter (TPPcarz+ = triphenyl (9-phenyl-9H-carbazol-3-yl) phosphonium), white LEDs (WLEDs) with a solution processed bilayer structure have been fabricated to exhibit a peak external quantum efficiency (EQE) of 4.8% and luminance of 1507 cd m-2 at the Commission Internationale de L'Eclairage (CIE) coordinate of (0.32, 0.35). This work opens a new pathway for creating highly efficient and stable WLEDs using metal halide perovskites and related materials.

Spiro-Carbon-Locking and Sulfur-Embedding Strategy for Constructing Deep-Red Organic Electroluminescent Emitter with High Efficiency.

The discovery of multiple resonance thermally activated delayed fluorescence (MR-TADF) materials with remarkable narrowband emission has opened a new avenue for the development of organic light-emitting diodes (OLEDs) with high color purity. However, the lack of construction strategies for purely red MR-TADF materials significantly impedes their application in full-color high-definition displays. Herein, we propose a unique and handy approach of spiro-carbon-locking and sulfur-embedding strategy to modify the parent MR-TADF framework, resulting in a red MR-TADF emitter with high color purity. The reported MR-TADF molecule (namely, FSBN) demonstrates a pure red emission with an emission maximum of 621 nm in toluene solution. The OLED with FSBN as emitter exhibits Commission Internationale de l'Éclairage (CIE) coordinates of (0.67, 0.33), which exactly matches the red standard defined by the National Television Standards Committee (NTSC). Importantly, the single-host OLED achieves a high power efficiency (PE) of up to 50.1 lm W-1, suggesting the potential for the development of low power consumption red OLEDs.

Spiro‐Carbon‐Locking and Sulfur‐Embedding Strategy for Constructing Deep‐Red Organic Electroluminescent Emitter with High Efficiency

The discovery of multiple resonance thermally activated delayed fluorescence (MR‐TADF) materials with remarkable narrowband emission has opened a new avenue for the development of organic light‐emitting diodes (OLEDs) with high color purity. However, the lack of construction strategies for purely red MR‐TADF materials significantly impedes their application in full‐color high‐definition displays. Herein, we propose a unique and handy approach of spiro‐carbon‐locking and sulfur‐embedding strategy to modify the parent MR‐TADF framework, resulting in a red MR‐TADF emitter with high color purity. The reported MR‐TADF molecule (namely, FSBN) demonstrates a pure red emission with an emission maximum of 621 nm in toluene solution. The OLED with FSBN as emitter exhibits Commission Internationale de l’Éclairage (CIE) coordinates of (0.67, 0.33), which exactly matches the red standard defined by the National Television Standards Committee (NTSC). Importantly, the single‐host OLED achieves a high power efficiency (PE) of up to 50.1 lm W−1, suggesting the potential for the development of low power consumption red OLEDs.

Lead‐free Halide Perovskites With ≈100% PLQY and Dual‐Color Emission for White Light‐Emitting Diodes

AbstractLead‐free halide perovskites (LHP) have attracted extensive attention in the field of next‐generation solid‐state lighting. However, single perovskite phosphor with tunable white‐light emission and ultra‐high photoluminescence quantum yield (PLQY) are rare. Here, the tunable dual‐color emission LHP phosphor is developed with a near‐unity PLQY of 99.5%. The LHP phosphor comprises Cs2NaInCl6: Sb3+/Bi3+ and Cs2InCl5·H2O: Sb3+/Bi3+ crystals, with the transition between these two perovskite structures being adjustable by the concentration of Na+. The addition of NaCl inhibits the hydrolysis of the [Sb(H2O)Cl5]2− octahedron, resulting in 3D connected [SbCl6]3− octahedron with less Jahn‐Teller distortion, and the PLQY of LHP is greater than 90%. Finally, the white‐light diode device is fabricated by assembling the LHP with a ultraviolet light‐emitting diode chip and the white light‐emitting diode device achieved Commission Internationale de l'Eclairage color coordinates of (0.34, 0.33), correlated color temperature of 4936 K, and a high color rendering index of 92.9. The LHP perovskite exhibited multimodal luminescence when excited by 365, 335, and 310 nm UV light, showing the multi‐mode anti‐counterfeiting capabilities of the LHP crystals.

White Light Emission in Europium‐Doped Inorganic Perovskite Single Matrix

AbstractThe realization of stable single‐component white light emission in metal halide perovskites is still challenging due to the fast halide ion migration and narrow luminescence bands. In this work, all‐inorganic single CsPbClxBr3−x perovskite microplates with stable red‐blue‐green triple color light emission are prepared by introducing europium ions Eu3+ as dopants. Eu doping effectively suppresses ion migration and enables two spatially separated halide phases with stable dual‐wavelength emissions. Furthermore, the incorporation of Eu3+ compensates for the absence of red‐light emission, thereby yielding a superior white emission with exceptional quality. The color rendering index of triple‐color‐emitting perovskites can be tuned successfully by controlling the halogen ratios, and the optimal microplate achieved a Commissions Internationale de l’Eclairage (CIE) coordinates of (0.32, 0.32). The results present a new enlightenment for the preparation of low‐cost single‐component white light materials.

Calcium vacancy enhanced self-reduction of Ce4+ for single-phase full-spectrum lighting and information encryption

Due to the wide and adjustable emission range, Ce3+ is an indispensable luminous center for full spectrum lighting. However, it needs to be sintered at high temperature in a reducing atmosphere, resulting in difficulty to coexisting with other multivalent activated ions (such as Eu3+, Tm3+), which greatly hinders the formation of full spectrum. In this study, a calcium vacancy enhanced self-reduction of Ce4+ is realized in CaNaSb2O6F (CNSOF) host under air atmosphere sintering, through which Ce3+, Tm3+ and Eu3+ coexisting in a single-phase full spectrum phosphor was prepared. Notably, the artificial introduction of a calcium vacancy was designed to verify this self-reduction mechanism. Moreover, the energy transfer kinetics among Tm3+, Ce3+ and Eu3+ were explored. Finally, combined with a 340 nm UV chip, a full spectrum phosphor-converted light-emitting diode (pc-LED) was fabricated, showing a broad emission range from 400 to 750 nm, Commission Internationale de I’Eclairage (CIE) of (0.3485, 0.3673), Ra of 92 and correlated color temperature (CCT) of 4933 K. Utilizing the variation in emission colors of this phosphor under different UV wavelengths, a dual encryption method combining point character code and fluorescent encryption technique is proposed. This work provides an effective path for Ce4+ self-reduction to apply in full spectrum pc-LED and information encryption.

Evaluating the general V(λ), mismatch spectral quality factor index ƒ₁ and the uncertainty of photometers

The general term photometry refers to the measurement of light and its perceived brightness; it can be applied to various purposes, including lighting design, display calibration, and the setting of safety standards. A device used for measuring light is called a light meter or photometer. Ideally, such devices should have a spectral responsivity-that is, they should respond to light in a way which mimics the human eye's sensitivity to different wavelengths. The sensitivity of the human eye is described by the Commission Internationale de l'Éclairage, CIE, luminous efficiency function, V(λ), a plot of the sensitivity of the eye versus wavelength over the visible region, from violet, approximately 380 nm, through red, approximately 780 nm. In practical applications, it is usually preferable to detect light with silicon or selenium photodetectors and measure the electrical current generated. These photodetectors are sensitive to a wide range of wavelengths, including those outside of the visible spectrum: ultraviolet (UV) and infrared (IR). However, due to its nature, the spectral responsivity of silicon and selenium photodetectors is also different from that of the human eye. For example, silicon photodetectors are much more sensitive to infrared radiation, which is imperceptible to human vision. This in turn leads to erroneous light measurements when using the direct raw response of the detector. The spectral quality factor and , indicating the mismatch between the spectral responsivity and the CIE luminous efficiency function V(λ), is the most crucial characteristic of photometers. The general mismatch index , denoted as V(λ), delineates the disparity between a photometer's relative spectral responsivity and the spectral luminous efficiency function for photopic vision, V(λ). It's highly probable that photometers will adopt white light-emitting diode (LED) sources as calibration references going forward. This transition may necessitate refining the general V(λ) mismatch index's definition, possibly through alternative normalization methods for or by introducing a different assessment function for evaluating mismatches . In this research, spectral quality factor for the photometer NIS-2 has been determined with value 3.8%. This percentage value is classified the photometer NIS-2 as medium quality. The uncertainty was determined through a calculation performed using my Microsoft Excel program, and the final value obtained is 0.010.

Hybrid Local and Charge Transfer Emitters Utilizing Hyperconjugation Effect Towards Solution‐Processed Ultra‐Deep‐Blue OLEDs with External Quantum Efficiency Approaching 12 %

AbstractHybrid local and charge transfer (HLCT) excited state materials, which possess weak donor‐acceptor (D–A) pure organic structures, deserve one of the most promising efficient and stable blue emitters. Through high‐lying reverse intersystem crossing (hRISC) process, 75 % triplet excitons generated by electrical excitation could be harvested and utilized in organic light‐emitting diodes (OLEDs). However, there are still significant challenges to achieve high‐efficiency ultra‐deep‐blue HLCT emitters with low Commission Internationale de l'Eclairage (CIE) 1931 chromaticity coordinate y values. Here, a series of novel blue HLCT emitters based on spiro[1,8‐diazafluorene‐9,2′‐imidazole] structure were designed and synthesized by fine‐tuning the spiro[fluorene‐9,2′‐imidazole] core structure in our previous work through heteroatom substitution and hyperconjugation effect. The target emitters were endowed with excellent photophysical and electrochemical merits, thermal stability and solution processibility. The solution‐processed OLED based on 4′,5′‐bis(4‐(9H‐carbazol‐9‐yl)phenyl)spiro[1,8‐diazafluorene‐9,2′‐imidazole] (NFIP‐CZ) achieved efficient ultra‐deep‐blue emission (CIEx,y=0.1581, 0.0422) with the maximum external quantum efficiency (EQEmax), maximum current efficiency (CEmax) and maximum power efficiency (PEmax) of 11.94 %, 4.07 cd ⋅ A−1 and 2.56 lm ⋅ W−1. The record EQE is a breakthrough in both solution‐processed and vacuum vapor deposition ultra‐deep‐blue HLCT OLEDs currently.

Color tunability, concentration dependence, and temperature responsive afterglow of SrZn2(PO4)2: Eu2+, Mn2+ phosphors.

Long persistent luminescence (LPL) materials with color adjustable afterglow have a wide application prospect in display and information encryption, yet there are few reports on such materials. In this paper, SrZn2(PO4)2 phosphors with tunable and thermal stimuli-responsive afterglow emissions were synthesized by a solid-state method. After ultraviolet (UV) excitation, the prepared samples exhibited emission at 419 nm, 533 nm, and 633 nm due to Eu2+: 4f65d1 → 4f7 transitions, Mn2+: 4T2(4G) →6A1(6S) transitions, and Mn2+: 4T1(4G) → 6A1(6S) transitions, respectively. The Commission Internationale de I' Eclairage (CIE) coordinates of samples can be changed among blue, white, and yellow by varying the Mn2+ concentration. Additionally, due to the differing thermal stability of Eu2+ and Mn2+, the phosphor exhibited a temperature-responsive afterglow, and its colors can be adjusted between white and yellow over a temperature range from 293 K to 383 K. Given its distinctive temperature-responsive afterglow, the prepared phosphor is suitable for use as a temperature sensor. Moreover, the tunable afterglow colors of the phosphors are advantageous for application in anti-counterfeiting.

Efficient Deep-Blue Fluorescent OLEDs Based on a D-π-A Emitter Profiting From Intramolecular Hydrogen Bonds and a Hybridized Excited State.

High performance deep-blue emitters with a Commission International de l'Eclairage (CIE) coordinate of CIEy≤0.08 are highly desired in ultrahigh-definition displays. Herein, we designed and synthesized an efficient D-π-A deep-blue emitter, 2-(6-([1,1' : 3',1''-terphenyl]-5'-yl)pyridin-3-yl)-1-phenyl-1H-phenanthro[9,10-d] imidazole (mPTPH), using the synergistic effect of intramolecular hydrogen bond (H-bond) and hybridized excited state. Single-crystal structure analysis confirmed that there exist intra- and intermolecular H-bond interactions which could inhibit the structure vibration and increase photoluminescence efficiency. The photophysical and theoretical results show that mPTPH exhibited hybridized local and charge-transfer (HLCT) feature with strong deep-blue emission. Ultimately, the non-doped device based on mPTPH exhibited high maximum luminance of 20610 cd m-2. The doped device achieved high maximum external quantum efficiency of 5.4 % and small efficiency roll-off with deep-blue emission peak of 413 nm and CIE coordinate of (0.16, 0.08).

Modulating Charge-Transfer Excited States of Multiple Resonance Emitters via Intramolecular Covalent Bond Locking.

Advanced multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters with high efficiency and color purity have emerged as a research focus in the development of ultra-high-definition displays. Herein, we disclose an approach to modulate the charge-transfer excited states of MR emitters via intramolecular covalent bond locking. This strategy can promote the evolution of strong intramolecular charge-transfer (ICT) states into weak ICT states, ultimately narrowing the full-width at half-maximum (FWHM) of emitters. To modulate the ICT intensity, two octagonal rings are introduced to yield molecule m-DCzDAz-BNCz. Compounds m-CzDAz-BNCz and m-DCzDAz-BNCz exhibit bright light-green and green fluorescence in toluene, with emission maxima of 504 and 513 nm, and FWHMs of 28 and 34 nm, respectively. Sensitized organic light-emitting diodes (OLEDs) employing emitters m-CzDAz-BNCz and m-DCzDAz-BNCz exhibit green emission with peaks of 508 and 520 nm, Commission Internationale de L'Eclairage (CIE) coordinates of (0.12, 0.65) and (0.19, 0.69), and maximum external quantum efficiencies (EQEs) of 30.2 % and 32.6 %, respectively.

Au···I coinage bonds: Boosting photoluminescence efficiency and solid‐state molecular motion

AbstractCoinage bonds, a type of noncovalent interaction, occur between group 11 elements (Au, Ag, and Cu) with electron donor groups. Despite theoretical validation, empirical evidence remains limited. In this study, an aggregation‐induced emission (AIE)‐active Au(I) complex, ITCPAu, which exhibits Au···I coinage bonds, was revealed based on the single‐crystal X‐ray diffraction and theoretical calculations. Further examination of the luminescence properties of the ITCPAu revealed multiswitchable behavior, including mechanochromism and thermochromism. Nearly pure white‐light emission was achieved with Commission Internationale de L'Eclairage (CIE) 1931 chromaticity coordinates of (0.30, 0.31) by grinding the green‐emissive ITCPAu monomer crystals. Moreover, visualization and manipulation of solid‐state molecular motion (SSMM) in the yellow‐emissive ITCPAu dimer crystals, driven by the robust Au···I coinage bonds, were revealed through a combination of crystal engineering and luminescent properties. Furthermore, to support the robust Au···I coinage bonds, a versatile carrier for small solvent molecules in crystal lattices was developed for uptake and release. Our findings provide experimental and theoretical evidence for Au···I coinage bonds, highlighting their ability to boost photoluminescence quantum yield (PLQY) and trigger SSMM, emphasizing their potential in developing smart materials with stimuli‐responsive properties.

Peripheral Substitution Engineering of MR-TADF Emitters Embedded With B‒N Covalent Bond Towards Efficient BT.2020 Blue Electroluminescence.

Compared with the classical boron/nitrogen (B/N) doped ones, multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters embedded with B-N covalent bond behave a significantly blue-shifted narrowband TADF, and thus show a greater potential in ultrapure blue organic light-emitting diodes (OLEDs). As a proof of concept, herein a peripheral substitution engineering is demonstrated based on such a B‒N embedded parent core. The simple approach is found to ensure easy synthesis via a one-pot lithium-free borylation-annulation, manipulate the excited states through different electronic coupling between core and substituent, and introduce the steric hindrance to minimize the unwanted spectral broadening. Impressively, ultrapure blue OLEDs are realized to give a high external quantum efficiency of 20.3% together with Commission Internationale de l'Éclairage coordinates of (0.152, 0.046). The performance is well competent with those of B/N doped MR-TADF emitters, clearly highlighting that the B‒N embedded framework is a novel promising paradigm towards efficient BT.2020 blue standard.

Unlocking the Luminescent Potential of Fish-Scale-Derived Carbon Nanoparticles for Multicolor Conversion.

This study introduces a novel approach to addressing environmental issues by developing fish-scale carbon nanoparticles (FSCNPs) with a wide range of colors from discarded fish scales. The process involves hydrothermally synthesizing raw tamban (Sardinella) fish scales sourced from Universal Canning, Inc. in Zamboanga City, Philippines. The optimization of the synthesis was achieved using the response surface methodology with a Box-Behnken design. The resulting FSCNPs exhibited unique structural and chemical properties akin to carbonized polymer dots, enhancing their versatility. The solid-state fluorescence of these nanoparticles can be modulated by varying their concentration in a polyvinylpyrrolidone matrix, yielding colors such as blue, green, yellow, and red-orange with Commission Internationale de l'Eclairage coordinates of (0.23, 0.38), (0.32, 0.43), (0.37, 0.43), and (0.46, 0.48), respectively. An analysis of the luminescence mechanism highlights cross-linking emissions, aggregation-induced emissions, and non-covalent interactions, which contribute to concentration-dependent fluorescence and tunable emission colors. These optical characteristics suggest that FSCNPs have significant potential for diverse applications, particularly in opto-electronic devices.

Copper‐Mediated C–H Cyclization of Heterocycles: Facile Access to Multiple Resonance Thermally Activated Delayed Fluorescence Materials

AbstractReported herein is the first example of a copper‐mediated C─H cyclization of heterocycles to construct structurally diverse carbonyl‐bridged triphenylamine compounds with multiple resonance thermally activated delayed fluorescence (TADF) characteristics. The one‐pot synthesis method exhibits a broad substrate scope and opens a new avenue for rapidly screening high‐performance organic TADF luminescent materials. Novel organic TADF single‐molecule white‐light material 5g with anti‐Kasha dual‐emission character is the first time developed herein and shows a Commission Internationale de l’Eclairage (CIE) coordinate of (0.33, 0.35) in the thin film, and can be used to fabricate robust and low cost organic white light‐emitting diodes (LED). Furthermore, the anti‐Kasha dual‐emission material 5g is fabricated as water‐dispersed nanoparticles (NPs)NPs, which can be efficiently endocytosed into the HeLa cells and dual emission imaging in living cells, and be used in two‐channel emission intensity ratio imaging to observe the intercellular structure.

Photoluminescence properties of Mn2+-activated red-emitting phosphors with superior thermal stability for backlighting display applications

The red-emitting phosphors, Na2Mg1-x(PO3)4:xMn2+ with concentrations ranging from 0.01 to 0.11, have been successfully synthesized using a simple solid-state method. The as-synthesized phosphors are crystallized in an orthorhombic structure. The luminescence mechanism of Mn2+ ions in Na2Mg(PO3)4 lattice has been deeply explained using the Tanabe-Sugano (T-S) energy level diagram for the d5 electron configuration. The typical photoluminescent emission (PL) and photoluminescent excitation (PLE) spectra were measured. Several excitation peaks in the spectral range of 250–550 nm on the PLE spectrum and a strong emission peak at 613 nm indicate that the as-synthesized phosphors can be effectively excited using ultraviolet (UV) and near-UV LED chips. Several photometric characteristics were measured, such as the Commission International de'LEclarirage (CIE) chromaticity coordinate (x, y), color purity (CP), and correlated color temperature (CCT), corresponding to the concentration-dependent PL spectra. Furthermore, the thermal stability of the Na2Mg1-x(PO3)4:xMn2+ phosphors was investigated through temperature-dependent PL spectra and decay curves from 10 to 500 K. All results confirm that the as-synthesized red-emitting phosphors exhibit excellent thermal stability, which are attractive characteristics for white light emitting diodes (W-LEDs) applications.

Pyrene-encapsulated light-emitting π-conjugated polymer with excellent ozone tolerance capacity for large-area and flexible ultra-deep-blue PLEDs with CIEy = 0.08

Emerging flexible polymer light-emitting diodes (PLEDs) are crucial for the development of information display and solid lighting. However, achieving ultrastable light-emitting polymers with robust emissions and outstanding chem-physic stabilities, remains a serious challenge due to the intrinsic oxidative and degrading properties of aromatic units. Herein, we present a universal and convenient pyrene-encapsulation strategy to enhance the ozone tolerance capacity of deep-blue light-emitting conjugated polymers (PPyDPF) for the narrowband flexible PLEDs. More intestingly, compared to the comparison polymers, PPyDPF showed a lower free volume ratio of 71.78 %, facilitating dense interchain packing, which contributes to its excellent ozone tolerance capacity. Large-area PLEDs were fabricated, which exhibit ultra-deep-blue emission with a FWHM of 40 nm and Commission internationale de l’éclairage (CIE) coordinates of (0.16, 0.08). The demonstrated potential for application in light-emitting devices underscores the significance of this approach, providing an effective strategy for developing aging-resistant light-emitting conjugated polymers for optoelectronic applications.

Enhanced Emitting Dipole Orientation Based on Asymmetric Iridium(III) Complexes for Efficient Saturated-Blue Phosphorescent OLEDs.

Three novel asymmetric Ir(III) complexes have been rationally designed to optimize their emitting dipole orientations (EDO) and enhance light outcoupling in blue phosphorescent organic light-emitting diodes (OLEDs), thereby boosting their external quantum efficiency (EQE). Bulky electron-donating groups (EDGs), namely: carbazole (Cz), di-tert-butyl carbazole (tBuCz), and phenoxazine (Pxz) are incorporated into the tridentate dicarbene pincer chelate to induce high degree of packing anisotropy, simultaneously enhancing their photophysical properties. Angle-dependent photoluminescence (ADPL) measurements indicate increased horizontal transition dipole ratios of 0.89 and 0.90 for the Ir(III) complexes Cz-dfppy-CN and tBuCz-dfppy-CN, respectively. Analysis of the single crystal structure and density functional theory (DFT) calculation results revealed an inherent correlation between molecular aspect ratio and EDO. Utilizing the newly obtained emitters, the blue OLED devices demonstrated exceptional performance, achieving a maximum EQE of 30.7% at a Commission International de l'Eclairage (CIE) coordinate of (0.140, 0.148). Optical transfer matrix-based simulations confirmed a maximum outcoupling efficiency of 35% due to improved EDO. Finally, the tandem OLED and hyper-OLED devices exhibited a maximumEQE of 44.2% and 31.6%, respectively, together with good device stability. This rational molecular design provides straightforward guidelines to reach highly efficient and stable saturated blue emission.