Wearable Electricity Generators Fabricated Utilizing Transparent Electronic Textiles Based on Polyester/Ag Nanowires/Graphene Core–Shell Nanocomposites

The technological realization of wearable triboelectric generators is attractive because of their promising applications in wearable self-powered intelligent systems. However, the low electrical conductivity, the low electrical stability, and the low compatibility of current electronic textiles (e-textiles) and clothing restrict the comfortable and aesthetic integration of wearable generators into human clothing. Here, we present high-performance, transparent, smart e-textiles that employ commercial textiles coated with silver nanowire/graphene sheets fabricated by using a scalable, environmentally friendly, full-solution process. The smart e-textiles show superb and stable conduction of below 20 Ω/square as well as excellent flexibility, stretchability, foldability, and washability. In addition, wearable electricity-generating textiles, in which the e-textiles act as electrodes as well as wearable substrates, are presented. Because of the high compatibility of smart e-textiles and clothing, the electricity-generating textiles can be easily integrated into a glove to harvest the mechanical energy induced by the motion of the fingers. The effective output power generated by a single generator due to that motion reached as high as 7 nW/cm². The successful demonstration of the electricity-generating glove suggests a promising future for polyester/Ag nanowire/graphene core–shell nanocomposite-based smart e-textiles for real wearable electronic systems and self-powered clothing

Wearable Electricity Generators Fabricated Utilizing Transparent Electronic Textiles Based on Polyester/Ag Nanowires/Graphene Core–Shell Nanocomposites

The technological realization of wearable triboelectric generators is attractive because of their promising applications in wearable self-powered intelligent systems. However, the low electrical conductivity, the low electrical stability, and the low compatibility of current electronic textiles (e-textiles) and clothing restrict the comfortable and aesthetic integration of wearable generators into human clothing. Here, we present high-performance, transparent, smart e-textiles that employ commercial textiles coated with silver nanowire/graphene sheets fabricated by using a scalable, environmentally friendly, full-solution process. The smart e-textiles show superb and stable conduction of below 20 Ω/square as well as excellent flexibility, stretchability, foldability, and washability. In addition, wearable electricity-generating textiles, in which the e-textiles act as electrodes as well as wearable substrates, are presented. Because of the high compatibility of smart e-textiles and clothing, the electricity-generating textiles can be easily integrated into a glove to harvest the mechanical energy induced by the motion of the fingers. The effective output power generated by a single generator due to that motion reached as high as 7 nW/cm². The successful demonstration of the electricity-generating glove suggests a promising future for polyester/Ag nanowire/graphene core–shell nanocomposite-based smart e-textiles for real wearable electronic systems and self-powered clothing

Boosting the Efficiency of High-Resolution Quantum Dot Light-Emitting Devices Based on Localized Surface Plasmon Resonance

With pixel miniaturization, the performance of high-resolution quantum dot light-emitting diodes (QLEDs) usually degrades. Considering the dimension of ultrasmall pixels, herein, a barrier architecture based on localized surface plasmon resonance (LSPR) that promotes the radiative recombination of neighboring quantum dots is rationally designed to improve the device performance. Au nanoparticles (NPs) are embedded in an insulating polymer to form a honeycomb-patterned barrier layer via the nanoimprint process. Each pixel fabricated in the void area (average diameter of 1.5 μm) of the barrier layer is surrounded by a number of LSPR-NPs to enhance the luminescence. The resultant green QLEDs with a resolution of 9027 pixels per inch show a maximum external quantum efficiency of 11.1%, a 42.8% enhancement compared to the control device. Additionally, the lifetime of high-resolution QLEDs is obviously improved by the LSPR effect

Fabrication of Large-Scale Microlens Arrays Based on Screen Printing for Integral Imaging 3D Display

The low-cost large-scale fabrication of microlens arrays (MLAs) with precise alignment, great uniformity of focusing, and good converging performance are of great importance for integral imaging 3D display. In this work, a simple and effective method for large-scale polymer microlens arrays using screen printing has been successfully presented. The results show that the MLAs possess high-quality surface morphology and excellent optical performances. Furthermore, the microlens’ shape and size, i.e., the diameter, the height, and the distance between two adjacent microlenses of the MLAs can be easily controlled by modifying the reflowing time and the size of open apertures of the screen. MLAs with the neighboring microlenses almost tangent can be achieved under suitable size of open apertures of the screen and reflowing time, which can remarkably reduce the color moiré patterns caused by the stray light between the blank areas of the MLAs in the integral imaging 3D display system, exhibiting much better reconstruction performance

Inkjet-Printed Photodetector Arrays Based on Hybrid Perovskite CH₃NH₃PbI₃ Microwires

Hybrid perovskite CH₃NH₃PbI₃ has attracted extensive research interests in optoelectronic devices in recent years. Herein an inkjet printing method has been employed to deposit a perovskite CH₃NH₃PbI₃ layer. By choosing the proper solvent and controlling the crystal growth rate, hybrid perovskite CH₃NH₃PbI₃ nanowires, microwires, a network, and islands were synthesized by means of inkjet printing. Electrode–gap–electrode lateral-structured photodetectors were fabricated with these different crystals, of which a hybrid perovskite microwire-based photodetector would balance the uniformity and low defects to obtain a switching ratio of 16000%, responsivity of 1.2 A/W, and normalized detectivity of 2.39 × 10¹² Jones at a light power density of 0.1 mW/cm². Furthermore, the hybrid perovskite microwire-based photodetector arrays were fabricated and applied in an imaging sensor, from which the clear mapping of the light source signal was successfully obtained. This work paves the way for the realization of low-cost, solution-processed, and high-performance hybrid perovskite-based photodetector arrays

Research on Suitable Viscosity and Driving Waveform of Chromatic Electrowetting with Good Photoelectric Characteristics

This paper proposes a kind of periodic complex ramp pulse driving waveform in the electrowetting display system with suitable viscosity ink. Firstly, considering the fluid-motion characteristics of different viscosity inks, the relationship between the contact angle and viscosity of inks in the liquid-oil-solid three-phase contact display system is calculated to obtain the suitable viscosity range and driving voltage range. Secondly, the physical model of ink motion with different viscosity is established by COMSOL simulation. Then, During the ink shrinkage movement after applying voltage, the change of the meniscus height at the oil-liquid interface is calculated. Finally, the appropriate viscosity range of the ink movement is verified and obtained based on the meniscus height. On this basis, after applying the driving voltage of different amplitude and frequency respectively, the ink movement situation is observed to design a suitable driving waveform. The results show that when the viscosity of ink fluid is between 0.005 and 0.015Pa·s, the higher the voltage amplitude and the lower the frequency, the higher the meniscus height of ink shrinkage, which is consistent with the characteristics of magenta ink tested in the experiment. Experimental tests show that the driving waveform designed in this paper can not only suppress the phenomenon of oil film splitting, backflow and contact angle saturation hysteresis, but also improve the ink response speed and pixel aperture ratio, in which the aperture ratio is increased to 68.69%. This research is of great significance to optimize the structure of fluid material and the design of driving in electrowetting display

Importance of Solvent Removal Rate on the Morphology and Device Performance of Organic Photovoltaics with Solvent Annealing

Solvent vapor annealing has been widely used in organic photovoltaics (OPV) to tune the morphology of bulk heterojunction active layer for the improvement of device performance. Unfortunately, the effect of solvent removal rate (SRR) after solvent annealing, which is one of the key factors that impact resultant morphology, on the morphology and device performance of OPV has never been reported. In this work, the nanoscale morphology of small molecule (SM):fullerene bulk heterojunction (BHJ) solar cell from different SRRs after solvent annealing was examined by small-angle neutron scattering and grazing incidence X-ray scattering. The results clearly demonstrate that the nanoscale morphology of SM:fullerene BHJ especially fullerene phase separation and concentration of fullerene in noncrystalline SM was significantly impacted by the SRR. The enhanced fullerene phase separation was found with a decrease of SRR, while the crystallinity and molecular packing of SM remained unchanged. Correlation to device performance shows that the balance between pure fullerene phase and mixing phase of SM and fullerene is crucial for the optimization of morphology and enhancement of device performance. Moreover, the specific interfacial area between pure fullerene phase and mixing phase is crucial for the electron transport and thus device performance. More importantly, this finding would provide a more careful and precise control of morphology of SM:fullerene BHJ and offers a guideline for further improvement of device performance with solvent annealing

Impact of Fullerene Structure on Nanoscale Morphology and Miscibility and Correlation of Performance on Small Molecules: Fullerene Solar Cell

This manuscript reports the impact of fullerene structure on the morphology and miscibility of small molecules via a fullerene bulk heterojunction solar cell. The small angle neutron scattering and neutron reflectometry measurements were analyzed to provide quantifiable measures of the morphology of the resultant mixtures, offering miscibility, domain sizes, interfacial area between the small molecule and fullerene, and depth profiles in the mixtures. These results indicate that the bis-adduct fullerenes exhibit lower miscibility in small molecules. Correlation of miscibility and morphology to photovoltaic properties indicates that small molecule/fullerene miscibility is crucial to rationally optimize the design of fullerenes for use in small molecule organic photovoltaics. A higher open circuit voltage was obtained for bis-adduct fullerene devices which, however, does not translate to an increased power conversion efficiency. This decrease in performance is associated with the lower miscibility of bis-fullerene, which decreases the probability of the dissociation of excitons and enhances charge recombination rate in the miscible region. A quantitative analysis shows that an increase in the average separation of fullerenes in the miscible region is detrimental to electron transport in the miscible region, especially for a distance greater than ∼11 Å

Supplementary document for Omnidirectional Color Shift Suppression of Full-color Micro-LED Displays with Enhanced Light Extraction Efficiency - 6306210.pdf

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Efficient All-Solution Processed Quantum Dot Light Emitting Diodes Based on Inkjet Printing Technique

Quantum dot light emitting diodes (QLEDs) are increasingly attractive owing to their compatibility with the inkjet printing process and potential application in low-cost large-area full-color pixelated display. The strategy for controlling the morphology of the quantum dot layer is definitely critical for realizing all-solution processed QLEDs with high performance, which certainly requires in-depth thinking regarding the design of ink composition and their optimization in the printing process. Herein, by carefully controlling the quantum dot ink composition and physicochemical properties, we demonstrate that the viscosity, contact angle, and the three-phase contact line moving would affect the final morphology of the quantum dot film formed by inkjet printing. We achieved coffee ring-free and low-roughness quantum dot film, and all-solution processed QLEDs with normal structure were fabricated for the first time. The devices have a low turn-on voltage of 2.0 V, a luminance of 12100 cd/m² at the voltage of 12 V, and a maximum current efficiency of 4.44 cd/A at the luminance of 1974 cd/m², which is the best result to date for inkjet-printed red QLEDs. The results will pave the way for future application of inkjet printing in solution processed pixelated QLED display