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Anti-blue light films with high transparency and low haze that completely originate from renewable and biodegradable biomass materials for eye protection is a growing trend with great demand in the near future. Therefore, in this study, a natural bioactive ingredient, lutein, was incorporated into the cellulose matrix via a green and facile adsorption strategy to prepare biodegradable ultraviolet (UV) and blue light filters. The lutein/carboxymethylated cellulose films (L-CCFs) displayed high anti-UV capacity, with UV-A and UV-B blocking ratios of 52.7 %-90.9 % and 44.1–85.2 %, respectively. The composite films could block 83.1–97.8 % of blue light in the 400−500 nm region while maintaining high transparency (86.6–89.3 %) and low haze (2.1–2.6 %). By light absorption, the films can effectively shield blue light emitted by light-emitting diodes, sunshine, lighting systems, mobile phone, and computer screens. Quite encouragingly, the addition of lutein significantly increased the water contact angle from 40.1 to 70.5° and the composite films have excellent liquid barrier properties. Meanwhile, these films exhibit higher light stability than lutein powders, thus greatly extending the service life of the film as a blue light shielding material. Moreover, the films have excellent mechanical strength (>110 MPa) and biodegradability. These films prepared entirely from natural resources offer great application value in the fields of electronic screen films and spectacle lenses. [Display omitted] • High tensile strength lutein-cellulose films were prepared for eye protection. • Lutein-cellulose films demonstrated UV and blue light double-blocking capacity. • Lutein-cellulose films exhibited high optical transmittance and low haze. • Compositing with lutein could improve water contact angle of films. [ABSTRACT FROM AUTHOR]

• Highly transparent and nearly superhydrophobic surface can be achieved. • The relationship between optical transmittance and etching depth was studied. • Surface roughness-dependent water contact angle and sliding angle were studied. Highly transparent, superhydrophobic coatings are highly desirable for maintaining long-lasting clarity for outdoor camera windows. In this study, the authors present a simple approach to create a wide–range anti-reflective and highly hydrophobic layer on a glass surface. This is accomplished through a hydrothermal alkali etching process combined with a dip-coating process using 1 H, 1 H, 2 H, 2 H-Perfluorooctyltrimethoxysilane (POTS). The sample, etched for 20 h and modified by POTS, exhibiting an average transmittance of 96.5 %, a water contact angle (WCA) of 140° and a sliding angle (SA) of 40°. The results of the water spray experiment indicate this surface exhibits excellent water repellent performance, preventing water droplets larger than 0.01 mm in size. The relationship between optical transmittance and etching depth was thoroughly studied, revealing that an etched depth ranging from 200 nm to 600 nm yields optimal wide-spectrum anti-reflective properties. Furthermore, the influence of surface roughness on apparent WCA and SA was investigated. It was found that root mean square (RMS) roughness can be an effective factor to predict the apparent WCA of a surface, while both the RMS roughness and morphological structure affect the SA. [ABSTRACT FROM AUTHOR]

• Put forward a transparent electrically responsive fluid to prepare focus-tunable lenticular microlens array (LMA) • The position of the lenticular microlens unit can be changed by switching the polarity of the electric field. • The proposed LMA with movable positions have potential applications in increasing the number of viewpoints in 3D displays. In this work, a focus-tunable lenticular microlens array (LMA) is demonstrated by coating an electro-responsive fluid - Acetyl tributyl citrate (ATBC) onto an in-plane switching (IPS) electrode. ATBC is a transparent liquid that is difficult to hydrolyzed, difficult to ionized, and has a wide working temperature range (-50 ∼ 260 ℃). At initial state, the ATBC film is smooth and flat, and the device has no lensing effect at this time. When a DC electric field is applied, the charge injected from the cathode polarizes the electronegative ATBC molecules and moves them toward the anode region, a wavy shape is formed and the device exhibit LMA lensing effect. After removing the voltage, the ATBC fluid rapidly returns to a flat state. When the voltage reaches 60 V, the focal length can reach as low as ∼ 180 μm. The proposed ATBC liquid lens has high transmittance, good thermal stability, compact structure, which has potential applications in imaging, information processing and 2D/3D displays. [ABSTRACT FROM AUTHOR]

Abstract The combination of dye or quantum dots sensitized solar cell and electrochromic device has led to the realization of the photoelectrochromic device (PECD). In this study, a PECD consisted of carbon quantum dots (CQDs) sensitized photoanode, poly(3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProDOT-Me 2) electrochromic film, Br-/Br 3 - with Li+ as electrolyte was fabricated, and it shows advantages of highly transparency for bleached state when compared with conventional photoelectrochromic device. As a PECD, it exhibits a reversible optical modulation under constant illumination (100 mW cm−2) by simply altering its circuit states between on and off. A high optical window of 54.6% with coloration time of 4.9 s, and bleaching time of 5.2 s was achieved at 580 nm. Additionally, stable switching for transmittance modulation after 400 cycles demonstrates its good cycle durability, exhibiting great potential in developing energy-saving applications. Graphical abstract Photoelectrochromic device based on carbon quantum dots was fabricated, achieving high optical window of 54.6% at 580 nm. fx1 Highlights • Photoelectrochromic device based on carbon quantum dots sensitized photoanode was fabricated. • Highly transparency of bleached states when compared with conventional PECD. • A high optical window of 54.6% with fast switching time could be achieved. • The optical modulation remaining stable after 400 cycles reveals good stability. [ABSTRACT FROM AUTHOR]

Transparent flexible electronics have captured tremendous attention as the next-generation of electronic devices. Recently, flexible devices for wearing are in high demand in practical applications under special circumstances, such as aeronautics and astronautics, which require highly-transparent and large-scale flexibility, as well as stability at elevated temperature. Here, highly transparent, epitaxial Pb(Zr 0.1 Ti 0.9 )O 3 (PZT) ferroelectric thin films were fabricated on Sn-doped In 2 O 3 (ITO) transparent electrodes on yttria-stabilized zirconia (YSZ) bufferred mica substrate using pulsed laser deposition. The structural, optical, mechanical, and electrical properties of these all-oxide heterostructures of the PZT/ITO/YSZ/mica were studied. The heteroepitaxy exhibit a high transmittance and an excellent remarkable mechanical properties with robust operation in bending cycle tests. Moreover, the electrical properties are examined to show the preservation of the primitive properties of PZT. Various bending tests are performed to show the tunability of functionalities and to confirm that the heterostructures retain the physical properties under repeated cycles at high temperature. These results demonstrated that these high-performance transparent flexible capacitors would open a route for the applications in transparent flexible devices under harsh conditions. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) generally suffer from aggregation-induced fluorescence quenching effect in solid-state, which significantly limits their application in photoelectric devices. Due to this effect, it is a great challenge to achieve high-transparency and high-performance luminescent solar concentrators (LSCs) based on CDs. Here, the synthesis of organosilane-grafted carbon dots (Si-CDs) is rationally designed by hydrothermal method using anhydrous citric acid, ethanolamine and KH-792 as the reaction precursors. The obtained Si-CDs can be uniformly dispersed in the polyvinyl alcohol (PVA) matrix through the dehydration condensation reaction and hydrogen bonding between the silicon hydroxyl group of Si-CDs and the hydroxyl group of PVA. Based on this property, Si-CDs/PVA thin-film LSCs (5 × 5 × 0.2 cm3) with ultrahigh CD loading (25 wt%) and high transparency can be fabricated, exhibiting excellent absorption in the UV spectral region and about 90 % transmission in the visible range. Furthermore, the power conversion efficiency (PCE) of the LSCs can reach 2.09 % under a standard solar light and shows excellent stability even over 12 weeks. This synthetic design is expected to be beneficial for future development of CD synthesis and paves the way for the development of CDs-based photoelectric devices. [Display omitted] • Rational design of organosilane grafted carbon dots (Si-CDs) by hydrothermal method is reported. • The Si-CDs can be uniformly dispersed in the polyvinyl alcohol (PVA) matrix through the dehydration condensation reaction. • Luminescent solar concentrators (LSCs) with ultrahigh CD loading (25 wt%) and ultrahigh transparency were fabricated. • The power conversion efficiency (PCE) of the LSCs could reach 2.09 % with excellent stability even over 12 weeks. [ABSTRACT FROM AUTHOR]

Solution-processed silver nanowires (AgNWs) have been considered as a promising material for next generation flexible transparent conductive electrodes. However AgNWs films have several intrinsic drawbacks, such as thermal stability and storage stability. Herein, we demonstrate a laminated ZnO/MgO (ZnMgO, ZMO) as a protective layer on the AgNWs films using atomic layer deposition (ALD). The fabricated films exhibited a low sheet resistance of 16 Ω/sq with high transmittance of 91% at 550 nm, an excellent thermal stability and bending property. The ZMO film grows perpendicularly on the surface of the AgNWs, making a perfect coverage of bulk silver nanowires and junction, which can effectively prompt the electrical transport behavior and enhance stability of the silver nanowires network. [ABSTRACT FROM AUTHOR]

Optical transparency, mechanical flexibility, and fast regeneration are important factors to expand the application of superhydrophobic surfaces. Herein, we fabricated highly transparent, stable, and superhydrophobic coatings through a novel gradient structure design by versatile dip-coating of silica colloid particles (SCPs) and diethoxydimethysiliane cross-linked silica nanoparticles (DDS-SNPs) on polyethylene terephthalate (PET) film and glass, followed by the modification of octadecyltrichlorosiliane (OTCS). When the DDS concentration reached 5 wt%, the modified SCPs/DDS-SNPs coating exhibited a water contact angle (WCA) of 153° and a sliding angle (SA) <5°. Besides, the average transmittance of this superhydrophobic coating on PET film and glass was increased by 2.7% and 1% in the visible wavelength, respectively. This superhydrophobic coating also showed good robustness and stability against water dropping impact, ultrasonic damage, and acid solution. Moreover, the superhydrophobic PET film after physical damage can quickly regain the superhydrophobicity by one-step spray regenerative solution of dodecyltrichlorosilane (DTCS) modified silica nanoparticles at room temperature. The demonstrated method for the preparation and regeneration of superhydrophobic coating is available for different substrates and large-scale production at room temperature. [ABSTRACT FROM AUTHOR]

• Highly transparent and submicrometer-grained Yb:Y 2 O 3 ceramics were prepared only by hot pressing for the first time. • The mechanical properties of hot-pressed Yb:Y 2 O 3 transparent ceramics have better mechanical properties than pressureless sintered samples. • The highest transmittance of the Yb:Y 2 O 3 ceramic was 81.7% at 1100 nm and 77.2% at 600 nm, which is near the theoretical value. Highly transparent and submicrometer-grained Yb:Y 2 O 3 ceramics were obtained by hot-pressing method with ZrO 2 sintering additive. Hot-pressing method provides extra driving force to promote the densification of Yb:Y 2 O 3 transparent ceramics, resulting in high transmittance achieved. The transmittances of all samples were ranging from 80.5% to 81.8% at 1100 nm and 72.7–77.7% at 600 nm. The ceramic samples in this work were sintered at a low temperature of 1600 ℃ for 3 h, providing dense microstructures with average grain size less than 1 µm, which are smaller than those of Yb:Y 2 O 3 ceramics prepared by other traditional sintering techniques. The microhardness and fracture toughness were ranging from 8.16 to 7.99 GPa, and from 0.94 to 0.88 MPa·m1/2, respectively, which are higher than the comparison samples fabricated by pressureless sintering. The absorption cross-sections of the 1 at% Yb-doped sample at 950 and 976 nm were 0.93 × 10−20 and 1.22 × 10−20 cm2, respectively. The fluorescence decay lifetime at 1032 nm was in the range of 0.79–1.36 ms. According to the available literature, this is the first report about Yb:Y 2 O 3 transparent ceramics fabricated by hot-pressing sintering without any combined sintering process. The ceramics obtained may have potential use for solid-state lasers partly replacing single crystals. [ABSTRACT FROM AUTHOR]

Abstract: In2O3 epitaxial thin films with heavy Nb doping have been investigated in expectation of achieving higher doping efficiency per doping atom than what has been achieved by Sn-doping because Nb has one more available valence electron. The films were deposited by co-sputtering of Nb and In2O3 on (001) YSZ substrates, and are found to follow the epitaxial relations of [001]In2O3||[001]YSZ and [110]In2O3||[110]YSZ aligned within Δω∼0.31–0.41° of full rocking width at half maximum (FWHM). The doped thin films present optical transparencies of 97–99 % with electrical resistivities down to 10−4 Ωcm, 100 times lower than the as-deposited pristine thin films of no intentional doping. Optimal doping efficiency of η max∼1 charge carrier per Nb-atom added, not the hoped 2, suggests an effective ionization state of Nb· In, much like Nb· Sn, rather than the anticipated Nb·· In. This singly-charged state is associated with the formation of Nb2O4 molecules by drawing extra interstitial Oi atoms to gather around the substitutional NbIn sites, as confirmed by XPS based on the chemical-shift of the X-ray photoelectron energy that measures the binding energy of core–shell electrons. Plasma oscillation analysis by FTIR optical spectroscopy shows an anomalously-high effective mass, about 10 times larger than the reported m ⁎=0.35m e. A dual-band model is proposed to reconcile with the findings. [Copyright &y& Elsevier]

Photonic image sensors with programmable non-volatile manifold memory can offer an essential breakthrough for the advancement of optoelectronic memory, smart machine vision, and optical neuromorphic computing. Here, we developed a two-terminal, nickel oxide and titanium dioxide-based, highly transparent (> 65%), non-volatile, programmable, self-powered ultraviolet photodetector. The self-powered photoresponse was customized at various levels by fine-tuning an electric pulse, even without changing illumination intensity. Moreover, the photodetector mimics the optical-electrical-coupled versatile features of a bio-synapse, such as manifold memory capability, paired-pulse facilitation, and excitation or depression. The observed results are quantitatively explained by the dynamics of oxygen vacancy migration-induced junction width modulation. Furthermore, photoconductive atomic force microscopy revealed a tunable and scalable (over the desired area) photocurrent even at the nanoscale (~30 nm), providing high-density integration, with a pixel density of ~716 GB/in2. Moreover, an array was developed and integrated with the well-developed camera, which was trained dynamically to memorize and classify the desired input optical patterns, demonstrating self-adaptive human-like visual perception. Our programmable photodetector represents a unique possibility to develop a trainable photoresponse that collects information for the desired shape, offering profound implications for building a complex, trainable, and energy‐efficient neuromorphic imaging system. Highly transparent, self-powered, multi-levels, and scalable neuromorphic photodetectors were developed and integrated with a commercially available camera. Zero-biased photocurrent mimics the optical-electrical-coupled self-adaptive human-like visual perception like trainable memorize, classify and recognize of input optical patterns. Furthermore, PC-AFM revealed a tunable and scalable photocurrent even at the nanoscale (~30 nm), providing high-density integration, with a pixel density of ~716 GB/in2. [Display omitted] • Two-terminal, highly transparent (>65%), non-volatile, programmable, self-powered ultraviolet photodetector is developed. • Self-powered photoresponse was customized at various levels by fine-tuning an electric pulse. • Photodetector mimics optical-electrical-coupled versatile features of a bio-synapse such as manifold memory capability. • Photoconductive AFM revealed tunable and scalable photocurrent, providing high-density integration of ~716 GB/in2. • Array was developed and integrated with the well-developed camera, demonstrating self-adaptive human-like visual perception. [ABSTRACT FROM AUTHOR]

• Highly transparent all oxide-based two-terminal solid-state artificial synapse. • Carrier selective layer plays a crucial role to provide the stability in two terminal artificial synapse. • The charge trapping/detrapping is the governing mechanism that confirmed by KPFM. • Nanoscale neuromorphic behavior has been confirmed by cAFM measurements. A synaptic device based on memristive switching that functionally mimics a biological synapse uses an electronic synapse (like a wire) to realize neuromorphic computing. Conventional two-terminal based memristors can be used for high-performing synaptic devices; however, these memristors suffer from several shortcomings (e.g. reproducibility) due to unstable filament formation during the switching process. Here, a solid state electronic synaptic device based on WO 3 /NiO/FTO heterostructures has been demonstrated. The typical artificial synaptic device behavior was observed from the current–voltage characteristics under consecutive voltage sweeps which revealing clockwise hysteresis. The schematic of the working mechanism of the solid-state electronic synapses revealed that the presence of the NiO layer, working as a carrier selective layer, enhances the trapping of charge carriers and thereby improves the stability and switching uniformity. In addition, from the analysis on the carrier transport mechanisms, the trap-filled assists space-charge-limited-current conduction mechanism is found to be dominant. This work will be an important step forward towards the realization of low-cost and transparent synaptic behavior. [ABSTRACT FROM AUTHOR]

• Fabrication of transparent, flexible, and light in weight PVA@WTR-CDs composite thin films. • Waste based, sustainable, green and fluorescent UV blocking agent (WTR-CDs). • Capable to absorb UV light and remission in the visible region. • Applicable in fruits packaging, coatings for various material and devices. Herein, we have fabricated a highly transparent, flexible and re-emissive polyvinyl alcohol/waste tea residue carbon dots (PVA@WTR-CDs) composite thin films by simple solvent casting method. Incorporated WTR-CDs as a function of UV blocking (absorption of UV light and re-emission in the visible region) agent synthesized from waste tea residue powder as a sustainable material. The results revealed that, the WTR-CDs have the best compatibility with PVA. The incorporated fluorescent WTR-CDs impart fluorescence to the whole film and films are capable to not only block the UV region but also re-emit absorbed UV light into the visible region. The increased concentrations of WTR-CDs into PVA films enhances the UV blocking capability of the composite films. The composite, PVA@WTR-CDs-3 films were succeeded to block full (100%) of UV-C (230−280 nm) and UV-B (280−315 nm) region, while 20−60% of UV-A (315−400 nm). We achieved the maximum of UV blocking by PVA@WTR-CDs-5 composite films by controlling the transparency and thickness. By the successive addition of the UV blocking agent, there was no extreme changes observed in the intrinsic mechanical as well as tensile properties of PVA films. The thermal analysis study showed that, there was no adverse effect of WTR-CDs incorporation on the thermal stability and degradation profile of original PVA films. In detail, the possible mechanism of UV absorption and re-emission in the visible region by fabricated films is also discussed. Furthermore, practicability of the composite film was also investigated on a model (grape) fruit and thus can be used as a modern UV blocking material in packaging, pharmaceutical storage, wrapping, and coating etc. [ABSTRACT FROM AUTHOR]

Intelligent neuromorphic tactile perception architecture requires the integration of pressure sensors, connecting cables, and artificial synapses, which poses serious challenges to complex device integration and overall energy consumption. Therefore, the development of self-adaptive, high performance and sophisticated artificial synapses with an uncomplicated fabrication process that can adjust its output with the tactile environment is essential. Here, we developed a proof-of-concept simple two-terminal, highly transparent, and flexible piezotronic artificial synapse that emulates environment-adaptable tactile perception. Specifically, all typical synaptic functions, such as excitation/depression, plasticity, and paired-pulse facilitation, are sensitive to the applied strain, thus providing artificial in-situ "touch sensing". The observed effect is attributed to the dynamic charge trapping/detraining via strain-modulated band alignment and is qualitatively confirmed by Kelvin probe force microscopy measurements. The presented work provides new insights into simplifying the circuitry of neuromorphic tactile perception, resulting in a number of additional applications toward skin‐attachable electronics, robotics, and prosthetics. A highly transparent, flexible, and piezotronic two-terminal artificial synapse has been developed that emulates environment-adaptable tactile perception. All typical synaptic functions, such as excitation/depression, plasticity, and paired-pulse facilitation, are sensitive to the applied strain, thus providing artificial in-situ "touch sensing". Presented work provides new insights into simplifying the circuitry of neuromorphic tactile perception toward skin‐attachable electronics, robotics, and prosthetics applications. Image 1 [ABSTRACT FROM AUTHOR]