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Nanopatterning driven by electrohydrodynamic (EHD) instability can aid in the resolution of the drawbacks inherent in conventional imprinting or other molding methods. This is because EHD force negates the requirement of physical contact and is easily tuned. However, its potential has not examined owing to the limited size of the pattern replica (several to tens of micrometers). Thus, this study proposes a new route for large-area patterning through high-speed evolution of EHD-driven pattern growth along the in-plane axis. Through the acceleration of the in-plane growth, while selectively controlling a specific edge growth, the pattern replica area can be extended from the micro- to centimeter scale with high fidelity. Moreover, even in the case of nonuniform contact mode, the proposed rapid in-plane growth mode facilitates uniform large-scale replication, which is not possible in conventional imprinting or other molding methods.
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The semiconductor thin film engineering technique plays a key role in the development of advanced electronics. Printing uniform nanofilms on freeform surfaces with high efficiency and low cost is significant for actual industrialization in electronics. Herein, a high-throughput colloidal printing (HTCP) strategy is reported for fabricating large-area and uniform semiconductor nanofilms on freeform surfaces. High-throughput and uniform printing rely on the balance of atomization and evaporation, as well as the introduced thermal Marangoni flows of colloidal dispersion, that suppresses outward capillary flows. Colloidal printing with in situ heating enables the fast fabrication of large-area semiconductor nanofilms on freeform surfaces, such as SiO2/Si, Al2O3, quartz glass, poly(ethylene terephthalate) (PET), Al foil, plastic tube, and Ni foam, expanding their technological applications where substrates are essential. The printed SnS2 nanofilms are integrated into thin-film semiconductor gas sensors with one of the fastest responses (8 s) while maintaining the highest sensitivity (Rg/Ra = 21) (toward 10 ppm NO2), as well as an ultralow limit of detection (LOD) of 46 ppt. The ability to print uniform semiconductor nanofilms on freeform surfaces with high-throughput promises the development of next-generation electronics with low cost and high efficiency.
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The tunable properties of 2D transition-metal dichalcogenide (TMDs) materials are extensively investigated for high-performance and wavelength-tunable optoelectronic applications. However, the precise modification of large-scale systems for practical optoelectronic applications remains a challenge. In this study, a wafer-scale atomic assembly process to produce 2D multinary (binary, ternary, and quaternary) TMDs for broadband photodetection is demonstrated. The large-area growth of homogeneous MoS2, Ni0.06Mo0.26S0.68, and Ni0.1Mo0.9S1.79Se0.21 is carried out using a succinct coating of the single-source precursor and subsequent thermal decomposition combined with thermal evaporation of the chalcogen powder. The optoelectrical properties of the multinary TMDs are dependent on the combination of heteroatoms. The maximum photoresponsivity of the MoS2-, Ni0.06Mo0.26S0.68-, and Ni0.1Mo0.9S1.79Se0.21-based photodetectors is 3.51 × 10-4, 1.48, and 0.9 A W-1 for 532 nm and 0.063, 0.42, and 1.4 A W-1 for 1064 nm, respectively. The devices exhibited excellent photoelectrical properties, which is highly beneficial for visible and near-infrared (NIR) photodetection.
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Excitation of Dirac plasmon polaritons (DPPs) in bi-dimensional materials have attracted considerable interest in recent years, both from perspectives of understanding their physics and exploring their transformative potential for nanophotonic devices, including ultra-sensitive plasmonic sensors, ultrafast saturable absorbers, modulators, and switches. Topological insulators (TIs) represent an ideal technological platform in this respect because they can support plasmon polaritons formed by Dirac carriers in the topological surface states. Tracing propagation of DPPs is a very challenging task, particularly at terahertz (THz) frequencies, where the DPP wavelength becomes over one order of magnitude shorter than the free space photon wavelength. Furthermore, severe attenuation hinders the comprehensive analysis of their characteristics. Here, the properties of DPPs in real TI-based devices are revealed. Bi2Se3 rectangular antennas can efficiently confine the propagation of DPPs to a single dimension and, as a result, enhance the DPPs visibility despite the strong intrinsic attenuation. The plasmon dispersion and loss properties from plasmon profiles are experimentally determined, along the antennas, obtained using holographic near-field nano-imaging in a wide range of THz frequencies, from 2.05 to 4.3 THz. The detailed investigation of the unveiled DPP properties can guide the design of novel topological quantum devices exploiting their directional propagation.
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The lithium deposited via the complex electrochemical heterogeneous lithium deposition reaction (LDR) process on a lithium foil-based anode (LFA) forms a high-aspect-ratio shape whenever the reaction kinetics reach its limit, threatening battery safety. Thereby, a research strategy that boosts the LDR kinetics is needed to construct a high-power and safe lithium metal anode. In this study, the kinetic limitations of the LDR process on LFA are elucidated through operando and ex situ observations using in-depth electrochemical analyses. In addition, ultra-thin (≈0.5 µm) and high modulus (≥19 GPa) double-walled carbon nanotube (DWNT) membranes with different surface properties are designed to catalyze high-safety LDRs. The oxygen-functionalized DWNT membranes introduced on the LFA top surface simultaneously induce multitudinous lithium nuclei, leading to film-like lithium deposition even at a high current density of 20 mA cm-2. More importantly, the layer-by-layer assembly of the oxygen-functionalized and pristine DWNT membranes results in different surface energies between the top and bottom surfaces, enabling selective surface LDRs underneath the high-modulus bilayer membranes. The protective LDR on the bilayer-covered LFA guarantees an invulnerable cycling process in large-area pouch cells at high current densities for more than 1000 cycles, demonstrating the practicability of LFA in a conventional liquid electrolyte system.
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Carbon-based perovskite solar cells (PSCs) coupled with solution-processed hole transport layers (HTLs) have shown potential owing to their combination of low cost and high performance. However, the commonly used poly(3-hexylthiophene) (P3HT) semicrystalline-polymer HTL dominantly shows edge-on molecular orientation, in which the alkyl side chains directly contact the perovskite layer, resulting in an electronically poor contact at the perovskite/P3HT interface. The study adopts a synergetic strategy comprising of additive and solvent engineering to transfer the edge-on molecular orientation of P3HT HTL into 3D molecular orientation. The target P3HT HTL possesses improved charge transport as well as enhanced moisture-repelling capability. Moreover, energy level alignment between target P3HT HTL and perovskite layer is realized. As a result, the champion devices with small (0.04 cm2) and larger areas (1 cm2) deliver notable efficiencies of 20.55% and 18.32%, respectively, which are among the highest efficiency of carbon-electrode PSCs.
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Reducing the defect density of perovskite films during the crystallization process is critical in preparing high-performance perovskite solar cells (PSCs). Here, a multi-functional molecule, 3-phenyl-4-aminobutyric acid hydrochloride (APH), with three functional groups including a benzene ring, âNH3 + and âCOOH, is added into the perovskite precursor solution to improve perovskite crystallization and device performance. The benzene ring increases the hydrophobicity of perovskites, while âNH3 + and âCOOH passivate defects related to I- and Pb2+, respectively. Consequently, the power conversion efficiency (PCE) of the optimal device increased to 24.65%. Additionally, an effective area of 1 cm2 with a PCE of 22.45% is also prepared using APH as an additive. Furthermore, PSCs prepared with APH exhibit excellent stability by 87% initial PCE without encapsulation after exposure at room temperature under 25% humidity for 5000 h and retaining 70% of initial PCE after aging at 85 °C in an N2 environment for 864 h.
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Thermal management is critical in contemporary electronic systems, and integrating diamond with semiconductors offers the most promising solution to improve heat dissipation. However, developing a technique that can fully exploit the high thermal conductivity of diamond, withstand high-temperature annealing processes, and enable mass production is a significant challenge. In this study, the successful transfer of AlGaN/GaN/3C-SiC layers grown on Si to a large-size diamond substrate is demonstrated, followed by the fabrication of GaN high electron mobility transistors (HEMTs) on the diamond. Notably, no exfoliation of 3C-SiC/diamond bonding interfaces is observed even after annealing at 1100 °C, which is essential for high-quality GaN crystal growth on the diamond. The thermal boundary conductance of the 3C-SiC-diamond interface reaches ≈55 MW m-2 K-1, which is efficient for device cooling. GaN HEMTs fabricated on the diamond substrate exhibit the highest maximum drain current and the lowest surface temperature compared to those on Si and SiC substrates. Furthermore, the device thermal resistance of GaN HEMTs on the diamond substrate is significantly reduced compared to those on SiC substrates. These results indicate that the GaN/3C-SiC on diamond technique has the potential to revolutionize the development of power and radio-frequency electronics with improved thermal management capabilities.
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The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has exceeded those of conventional thin-film solar cell technologies, and the speed at which this increase has been achieved is unprecedented in the history of photovoltaics. Despite the significant progress achieved by PSCs at the laboratory level, their commercial prospects still face two significant challenges: scaling up in size and ensuring long-term stability. Small-area devices (~1 cm2) are typically fabricated using spin-coating. However, this approach may not be suitable for preparing the large-area (>100 cm2) substrates required for commercialization. Thus, new materials and methods must be developed to facilitate the coating of large-area PSCs. This review will discuss the development of scaling up organic-inorganic hybrid PSCs and the challenges of increasing the device area. Furthermore, it will provide an overview of the methodologies for achieving high-efficiency perovskite solar modules.
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Emerging technology has immense potential to increase the scale and efficiency of marine conservation. One such technology is large-area imaging (LAI), which relies on structure-from-motion photogrammetry to create composite products, including 3-dimensional (3-D) environmental models, that are larger in spatial extent than the individual images used to create them. Use of LAI has become widespread in certain fields of marine science, primarily to measure the 3D structure of benthic ecosystems and track change over time. However, the use of LAI in the field of marine conservation appears limited. We conducted a review of the coral reef literature on the use of LAI to identify research themes and regional trends in applications of this technology. We also surveyed 135 coral reef scientists and conservation practitioners to determine community familiarity with LAI, evaluate barriers practitioners face in using LAI, and identify applications of LAI believed to be most exciting or relevant to coral conservation. Adoption of LAI was limited primarily to researchers at institutions based in advanced economies and was applied infrequently to conservation, although conservation practitioners and survey respondents from emerging economies indicated they expect to use LAI in the future. Our results revealed disconnect between current LAI research topics and conservation priorities identified by practitioners, highlighting the need for more diverse, conservation-relevant research using LAI. We provide recommendations for how early adopters of LAI (typically Global North scientists from well-resourced institutions) can facilitate access to this conservation technology. These recommendations include developing training resources, creating partnerships for data storage and analysis, publishing standard operating procedures for LAI workflows, standardizing methods, developing tools for efficient data extraction from LAI products, and conducting conservation-relevant research using LAI.
Reducción de la brecha entre la investigación actual de imágenes de gran superficie y las necesidades de la conservación marina Resumen Las nuevas tecnologías tienen un enorme potencial para aumentar la escala y la eficiencia de la conservación marina. Una de ellas son las imágenes de gran superficie (IGS), que se basan en la fotogrametría de estructura a partir del movimiento para crear productos compuestos, incluidos modelos ambientales tridimensionales (3D), cuya extensión espacial es mayor que la de las imágenes individuales utilizadas para crearlos. El uso de las IGS se ha generalizado en determinados campos de las ciencias marinas, principalmente para medir la estructura tridimensional de los ecosistemas bentónicos y realizar un seguimiento de los cambios a lo largo del tiempo. Sin embargo, el uso de las IGS en el campo de la conservación marina parece limitado. Realizamos una revisión de la bibliografía sobre el uso de las IGS en los arrecifes de coral para identificar temas de investigación y tendencias regionales en las aplicaciones de esta tecnología. También encuestamos a 135 científicos de arrecifes de coral y profesionales de la conservación para determinar la familiaridad de la comunidad con las IGS, evaluar las barreras a las que se enfrentan los profesionales en el uso de las IGS e identificar sus aplicaciones consideradas como las más interesantes o relevantes para la conservación del coral. La adopción de las IGS se limitó principalmente a los investigadores de las instituciones con sede en las economías avanzadas y se aplicó con poca frecuencia a la conservación, aunque los profesionales de la conservación y los encuestados de las economías emergentes indicaron que esperan utilizar las IGS en el futuro. Nuestros resultados revelaron una desconexión entre los actuales temas de investigación de las IGS y las prioridades de conservación identificadas por los profesionales, lo que subraya la necesidad de una investigación más diversa y relevante para la conservación mediante el uso de las IGS.
Assuntos
Antozoários , Ecossistema , Animais , Conservação dos Recursos Naturais/métodos , Recifes de CoraisRESUMO
The lack of low-cost methods to synthesize large-area graphene-based materials is still an important factor that limits the practical application of graphene devices. Herein, we present a facile method for producing large-area graphene oxide-metal (GO-M) films, which are size controllable and transferable. The sensor constructed using the GO-M film exhibited humidity sensitivity while being unaffected by pressure. The relationship between the sensor's resistance and relative humidity followed an exponential trend. The GO-Mg sensor was the most sensitive among all the tested sensors. The facile synthesis of GO-M films will accelerate the widespread utilization of graphene-based materials.
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In the realm of molecular detection, the surface-enhanced Raman scattering (SERS) technique has garnered increasing attention due to its rapid detection, high sensitivity, and non-destructive characteristics. However, conventional rigid SERS substrates are either costly to fabricate and challenging to prepare over a large area, or they exhibit poor uniformity and repeatability, making them unsuitable for inspecting curved object surfaces. In this work, we present a flexible SERS substrate with high sensitivity as well as good uniformity and repeatability. First, the flexible polydimethylsiloxane (PDMS) substrate is manually formulated and cured. SiO2/Ag layer on the substrate can be obtained in a single process by using ion beam sputtering. Then, reactive ion etching is used to etch the upper SiO2layer of the film, which directly leads to the desired densely packed nanostructure. Finally, a layer of precious metal is deposited on the densely packed nanostructure by thermal evaporation. In our proposed system, the densely packed nanostructure obtained by etching the SiO2layer directly determines the SERS ability of the substrate. The bottom layer of silver mirror can reflect the penetrative incident light, the spacer layer of SiO2and the top layer of silver thin film can further localize the light in the system, which can realize the excellent absorption of Raman laser light, thus enhancing SERS ability. In the tests, the prepared substrates show excellent SERS performance in detecting crystalline violet with a detection limit of 10-11M. The development of this SERS substrate is anticipated to offer a highly effective and convenient method for molecular substance detection.
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Dual-layer detectors provide a low-cost solution to improved material decomposition and lesion differentiation in X-ray imaging, while eliminating motion artifacts from multiple exposures. Most designs utilize two indirect detectors with scintillators designed for low-energy and higher-energy detection and separated by a copper filter to harden the beam for high energy detection. To improve the performance of the bottom detector and lower dose requirements, we have previously proposed an alloyed amorphous selenium photodetector to achieve improved resolution and absorption at green wavelengths, better suited to high-performance scintillators such as CsI:Tl. In this work, we demonstrate a baseline prototype for the bottom layer-a continuous, large area 83 µm pixel pitch flat panel indirect detector with well-established amorphous selenium as the photodetector-and verify the architecture's performance and detector design. We characterize lag, noise-power spectrum, detective quantum efficiency, and modular transfer function of the detector, and show resolution up to 6 lp/mm when operated at an applied bias of 150 V. This provides a starting point for evaluating the alloyed selenium materials, and shows promise for this detector in the future dual-layer design.
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High-precision temperature control of large-area blackbodies has a pivotal role in temperature calibration and thermal imaging correction. Meanwhile, it is necessary to correct the temperature difference between the radiating (surface of use) and back surfaces (where the temperature sensor is installed) of the blackbody during the testing phase. Moreover, large-area blackbodies are usually composed of multiple temperature control channels, and manual correction in this scenario is error-prone and inefficient. At present, there is no method that can achieve temperature-automated calibration for a large-area blackbody radiation source. Therefore, this article is dedicated to achieving temperature-automated calibration for a large-area blackbody radiation source. First, utilizing two calibrated infrared thermometers, the optimal temperature measurement location was determined using a focusing algorithm. Then, a three-axis movement system was used to obtain the true temperature at the same measurement location on a large-area blackbody surface from different channels. This temperature was subtracted from the blackbody's back surface. The temperature difference was calculated employing a weighted algorithm to derive the parameters for calibration. Finally, regarding experimental verification, the consistency error of the temperature measurement point was reduced by 85.4%, the temperature uniformity of the surface source was improved by 40.4%, and the average temperature measurement deviation decreased by 43.8%. In addition, this system demonstrated the characteristics of strong environmental adaptability that was able to perform temperature calibration under the working conditions of a blackbody surface temperature from 100 K to 573 K, which decreased the calibration time by 9.82 times.
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In this study, a controllable equal-gap large-area silicon drift detector (L-SDD) is designed. The surface leakage current is reduced by reducing the SiO2-Si interface through the new controllable equal-gap design. The design of the equal gap also solves the problem whereby the gap widens due to the larger detector size in the previous SDD design, which leads to a large invalid area of the detector. In this paper, a spiral hexagonal equal-gap L-SDD of 1 cm radius is selected for design calculation, and we implement 3D modeling and simulation of the device. The simulation results show that the internal potential gradient distribution of the L-SDD is uniform and forms a drift electric field, with the direction of electron drift pointing towards the collecting anode. The L-SDD has an excellent electron drift channel inside, and this article also analyzes the electrical performance of the drift channel to verify the correctness of the design method of the L-SDD.
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Despite the rapid progress in perovskite light-emitting diodes (PeLEDs), the electroluminescence performance of large-area perovskite devices lags far behind that of laboratory-size ones. Here, we report a 3.5 cm × 3.5 cm large-area PeLED with a record-high external quantum efficiency of 12.1% by creating an amphipathic molecular interface modifier of betaine citrate (BC) between the perovskite layer and the underlying hole transport layer (HTL). It is found that the surface wettability for various HTLs can be efficiently improved as a result of the coexistence of methyl and carboxyl groups in the BC molecules that makes favorable groups to selectively contact with the HTL surface and increases the surface free energy, which greatly facilitates the scalable process of solution-processed perovskite films. Moreover, the luminous performance of perovskite emitters is simultaneously enhanced through the coordination between CâO in the carboxyl groups and Pb dangling bonds.
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Despite the great success of perovskite photovoltaics in terms of device efficiency and stability using laboratory-scale spin-coating methods, the demand for high-throughput and cost-effective solutions remains unresolved and rarely reported because of the complicated nature of perovskite crystallization. In this work, we propose a stable precursor ink design strategy to control the solvent volatilization and perovskite crystallization to enable the wide speed window printing (0.3 to 18.0â m/min) of phase-pure FAPbI3 perovskite solar cells (pero-SCs) in ambient atmosphere. The FAPbI3 perovskite precursor ink uses volatile acetonitrile (ACN) as the main solvent with DMF and DMSO as coordination additives is beneficial to improve the ink stability, inhibit the coffee rings, and the complicated intermediate FAPbI3 phases, delivering high-quality pin-hole free and phase-pure FAPbI3 perovskite films with large-scale uniformity. Ultimately, small-area FAPbI3 pero-SCs (0.062â cm2 ) and large-area modules (15.64â cm2 ) achieved remarkable efficiencies of 24.32 % and 21.90 %, respectively, whereas the PCE of the devices can be maintained at 23.76 % when the printing speed increases to 18.0â m/min. Specifically, the unencapsulated device exhibits superior operational stability with T90 >1350â h. This work represents a step towards the scalable, cost-effective manufacturing of perovskite photovoltaics with both high performance and high throughput.
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Ultrathin continuous metal-organic framework (MOF) membranes have the potential to achieve high gas permeance and selectivity simultaneously for otherwise difficult gas separations, but with few exceptions for zeolitic-imidazolate frameworks (ZIF) membranes, current methods cannot conveniently realize practical large-area fabrication. Here, we propose a ligand back diffusion-assisted bipolymer-directed metal ion distribution strategy for preparing large-area ultrathin MOF membranes on flexible polymeric support layers. The bipolymer directs metal ions to form a cross-linked two-dimensional (2D) network with a uniform distribution of metal ions on support layers. Ligand back diffusion controls the feed of ligand molecules available for nuclei formation, resulting in the continuous growth of large-area ultrathin MOF membranes. We report the practical fabrication of three representative defect-free MOF membranes with areas larger than 2,400â cm2 and ultrathin selective layers (50-130â nm), including ZIFs and carboxylate-linker MOFs. Among these, the ZIF-8 membrane displays high gas permeance of 3,979â GPU for C3H6, with good mixed gas selectivity (43.88 for C3H6/C3H8). To illustrate its scale-up practicality, MOF membranes were prepared and incorporated into spiral-wound membrane modules with an active area of 4,800â cm2. The ZIF-8 membrane module presents high gas permeance (3,930â GPU for C3H6) with acceptable ideal gas selectivity (37.45 for C3H6/C3H8).
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Perovskite light-emitting diodes (PeLEDs) that can be air-processed promises the development of displaying optoelectronic device, while is challenged by technical difficulty on both the active layer and hole transport layer (HTL) caused by the unavoidable humidity interference. Here, we propose and validate that, planting the polymer brush with tailored functional groups in inorganic HTL, provides unique bilateral embedded anchoring that is capable of simultaneously addressing the n phases crystallization rates in the active layer as well as the deteriorated particulate surface defects in HTL. Exemplified by zwitterionic polyethyleneimine-sulfonate (PEIS) in present study, its implanting in NiOx HTL offers abundant nuclei sites of amino and sulfonate groups that balance the growth rate of different n phases in quasi-2D perovskite films. Moreover, the PEIS effectively nailed the interfacial contact between perovskite and NiOx, and reduced the particulate surface defects in HTL, leading to the enhanced PLQY and stability of large-area blue perovskite film in ambient air. By virtue of these merits, present work achieves the first demonstration of the air-processed blue PeLEDs in large emitting area of 1.0 cm2 with peak external quantum efficiency (EQE) of 2.09 %, which is comparable to the similar pure-bromide blue PeLEDs fabricated in glovebox.
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Near-infrared light-emitting diodes (NIR LEDs) based on perovskite quantum dots (QDs) have produced external quantum efficiency (EQE) of ~15 %. However, these high-performance NIR-QLEDs suffer from immediate carrier quenching because of the accumulation of migratable ions at the surface of the QDs. These uncoordinated ions and carriers-if not bound to the nanocrystal surface-serve as centers for exciton quenching and device degradation. In this work, we overcome this issue and fabricate high-performance NIR QLEDs by devising a ligand anchoring strategy, which entails dissolving the strong-binding ligand (Guanidine Hydroiodide, GAI) in the mediate-polar solvent. By employing the dye-sensitized device structure (phosphorescent indicator), we demonstrate the elimination of the interface defects. The treated QDs films exhibit an exciton binding energy of 117â meV: this represents a 1.5-fold increase compared to that of the control (74â meV). We report, as a result, the NIR QLEDs with an EQE of 21 % which is a record among NIR perovskite QLEDs. These QLEDs also exhibit a 7-fold higher operational stability than that of the best previously reported NIR QLEDs. Furthermore, we demonstrate that the QDs are compatible with large-area QLEDs: we showcase 900â mm2 QLEDs with EQE approaching 20 %.