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Mechanoluminescence (ML) with the unique mechanical‐to‐optical energy conversion attracts wide attention for stress sensing. However, the development of ML materials is primarily based on crystalline material due to the crystal structure can provide an appropriate crystal field environment for emission center, which limits the expansion of ML materials and affects the deeper understanding of ML mechanism. Herein, the tunable full‐color ML can be achieved in transparent amorphous glass system. The rare earth‐doped transparent amorphous glass can produce ML under stress stimulations when in direct contact with polydimethylsiloxane (PDMS) or mixed with PDMS to prepare the ML elastomers. Based on the excellent ML performance of amorphous glass, an advanced device regarding the visualized detection of automotive brake tribo‐force has been developed. The findings provide profound insights into the triboelectric potential induced ML phenomenon, which offers the guiding significance in the mechanics‐related visualized detection and the design of multi‐color ML materials in the future. [ABSTRACT FROM AUTHOR]

Highly transparent Ho:Y2O3 ceramics for laser diode lighting were prepared using the vacuum sintering method with 0.3 at.% Nb2O5 as a sintering additive. The microstructures, transmittance, and luminescence properties of the Ho:Y2O3 ceramic samples were investigated in detail. The transmittance levels of all samples with various Ho3+ concentrations reached ~81.5% (2 mm thick) at 1100 nm. Under the excitation of 363 nm (ultraviolet) or 448 nm (blue) light, Ho:Y2O3 transparent ceramic samples showed that green emission peaked at 550 nm. The emission intensity was strongly affected by the concentration of Ho3+ ions, reaching its highest level in the sample doped with 1 at.% Ho3+. The CIE coordinates of the luminescence were in the green region (i.e., the CIE coordinates of the sample doped with 1 at.% Ho3+ were [0.27, 0.53] and [0.30, 0.69], under the excitation of 363 nm and 448 nm light, respectively). The possibility of its application as laser diode lighting was reported. Under the excitation of 450 nm blue laser, the sample doped with 0.5 at.% Ho3+ had the best performance: the saturated luminous flux, lumen efficiency, and the luminescence saturation power densities were 800 lm, 57.7 lm/W, and 17.6 W/mm2, respectively. Furthermore, the materials have high thermal conductivity and mechanical strength due to their host of rare-earth sesquioxide. Thus, Ho:Y2O3 transparent ceramics are expected to be a promising candidate for green-light-emitting devices for solid-state lighting, such as laser diode lighting. [ABSTRACT FROM AUTHOR]

Constructing a solar-powered photothermal system that can self-regulate temperature without requiring extra energy input is significant for energy saving, but how to achieve zero-energy building remains challenging. Here, a photothermal system that integrates sunlight harvesting, photothermal conversion (PTC), and heat storage was constructed. Well-developed nanoscale pore silica aerogels with high transparency (visible-light transmittance 69.3%, near-infrared transmittance 86.9%), bending resistance (bending angle >30°), and low thermal conductivity were prepared by the interpenetration of C and Si molecular networks using vinyltrimethoxysilane as the silica source, which was used as a window material for the temperature self-regulating system to block heat loss and allow sunlight transmission. Simultaneously, the prepared CsxWO3 (CWO) film with PTC could convert sunlight into heat. Also, PEG 2000 is introduced into the system with a suitable phase transition temperature to further realize temperature self-regulation within a certain range. The outdoor simulation test results showed that the system could heat water to 69.8 °C using sunlight in cold weather around 0 °C, which was 67.6 °C higher than the ambient temperature and can stay above 18 °C for about 20 h, and even in cloudy weather, it could reach 58.2 °C. The highly transparent silica aerogel is given the ability to resist bending, which opens up more application prospects for silica aerogels, and the constructed self-regulating temperature system without additional energy input contributes to the development of the zero-energy building. [ABSTRACT FROM AUTHOR]

Highly transparent Er:Y2O3 ceramics (1–9 at.% Er) were fabricated by hot pressing sintering with ZrO2 as the sintering additive. The microstructures, transmittance, luminescent properties, thermal conductivity, and mechanical properties of the Er:Y2O3 ceramic samples were investigated in detail. The samples all exhibited dense and fine grain microstructures; the average grain sizes were about 0.8 μm. The transmittance levels of the samples with various Er concentrations (2 mm thick) at the wavelengths of 600 and 2700 nm were ~74 and ~83%, respectively. As the Er doping concentration increased from 1 to 9 at.%, the up-conversion luminescence of the samples gradually changed from green to red, with the intensity ratio of red/green light increasing from 0.28 to 2.01. Meanwhile, the down-conversion luminescence properties of the specimens were also studied. When the samples were under 980 nm excitation, the emission bands were detected at 1552, 1573, 1639, and 1661 nm. The thermal conductivity of the samples was found to decrease from 8.72 to 5.81 W/(m·K) with an increase of the Er concentration from 1 to 9 at.%. Moreover, the microhardness and fracture toughness of the samples with 1 at.% Er concentration were ~8.51 GPa and ~1.03 MPa·m1/2, respectively. [ABSTRACT FROM AUTHOR]

Highly transparent Ho:Y2O3 ceramics for laser diode lighting were prepared using the vacuum sintering method with 0.3 at.% Nb2O5 as a sintering additive. The microstructures, transmittance, and luminescence properties of the Ho:Y2O3 ceramic samples were investigated in detail. The transmittance levels of all samples with various Ho3+ concentrations reached ~81.5% (2 mm thick) at 1100 nm. Under the excitation of 363 nm (ultraviolet) or 448 nm (blue) light, Ho:Y2O3 transparent ceramic samples showed that green emission peaked at 550 nm. The emission intensity was strongly affected by the concentration of Ho3+ ions, reaching its highest level in the sample doped with 1 at.% Ho3+. The CIE coordinates of the luminescence were in the green region (i.e., the CIE coordinates of the sample doped with 1 at.% Ho3+ were [0.27, 0.53] and [0.30, 0.69], under the excitation of 363 nm and 448 nm light, respectively). The possibility of its application as laser diode lighting was reported. Under the excitation of 450 nm blue laser, the sample doped with 0.5 at.% Ho3+ had the best performance: the saturated luminous flux, lumen efficiency, and the luminescence saturation power densities were 800 lm, 57.7 lm/W, and 17.6 W/mm2, respectively. Furthermore, the materials have high thermal conductivity and mechanical strength due to their host of rare-earth sesquioxide. Thus, Ho:Y2O3 transparent ceramics are expected to be a promising candidate for green-light-emitting devices for solid-state lighting, such as laser diode lighting.

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 Er:Y2O3 ceramics (1–9 at.% Er) were fabricated by hot pressing sintering with ZrO2 as the sintering additive. The microstructures, transmittance, luminescent properties, thermal conductivity, and mechanical properties of the Er:Y2O3 ceramic samples were investigated in detail. The samples all exhibited dense and fine grain microstructures; the average grain sizes were about 0.8 μm. The transmittance levels of the samples with various Er concentrations (2 mm thick) at the wavelengths of 600 and 2700 nm were ~74 and ~83%, respectively. As the Er doping concentration increased from 1 to 9 at.%, the up-conversion luminescence of the samples gradually changed from green to red, with the intensity ratio of red/green light increasing from 0.28 to 2.01. Meanwhile, the down-conversion luminescence properties of the specimens were also studied. When the samples were under 980 nm excitation, the emission bands were detected at 1552, 1573, 1639, and 1661 nm. The thermal conductivity of the samples was found to decrease from 8.72 to 5.81 W/(m·K) with an increase of the Er concentration from 1 to 9 at.%. Moreover, the microhardness and fracture toughness of the samples with 1 at.% Er concentration were ~8.51 GPa and ~1.03 MPa·m1/2, respectively.

Effectively insulating against excessive heat generated by sunlight while also avoiding harmful ultraviolet (UV) and maintaining suitable levels of visible light transparency is vital for minimizing energy consumption and optimizing sunlight utilization. To address the challenge of photothermal collaborative management, the PI consisted of high fluorinated dianhydride and aliphatic diamine was used to effectively improve the performance of SiO 2 aerogels. The resulting PI-SiO 2 aerogels retain the characteristics of SiO 2 aerogels, such as low density, high transparency between 82∼89 %, and excellent thermal insulation properties with an ultralow thermal conductivity range from 0.023 W/(m.K) to 0.028 W/(m.K). Meanwhile, the coarsened skeleton of aerogels can withstand the extreme temperature difference between −196 ℃ and 200 ℃ without brittle fracture and yellowing. In addition, PI-SiO 2 aerogels exhibit the capability to absorb a significant proportion of UV light within the 200–400 nm, offering distinct advantages in transparent thermal insulation materials. The multifunctional PI-SiO 2 aerogels can be used as candidate materials in the fields of architecture, automobile, electronics, solar energy and aerospace. • An effective method was utilized to prepare highly transparent aerogels. • The PI consisted of high fluorinated dianhydride and aliphatic diamine was selected to improve SiO 2 gel skeleton. • Aerogels integrated high transparency, thermal insulation and UV-shielding properties. • Aerogels can be used in the temperature range of −196 °C to 200 °C. [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]

Chitin and gelatin are biodegradable and biocompatible polymers which have gained much attention applied as bio-based materials. In this study, Chitin nanofiber (ChNF)/gelatin nanocomposite was synthesized by immersion method followed with drying at room temperature. The ChNF content in the ChNF/gelatin was controlled in a broad range by changing the concentration of gelatin solutions from 2, 5 to 10% during the immersion processes. The prepared ChNF/gelatin showed uniformly nanofiber network structures which embedded inside the gelatin matrix. The UV measurement indicated that the transmittance of ChNF was increased to as high as 88.7% from 65% at 600 nm, regardless of nanofiber content. Young’s modulus of the 50.2%-ChNF/gelatin (with the ChNF content of 50.2%) was around 5192 MPa, which was almost two times higher than that of the pure gelatin. This mechanical improvement was attributed to the reinforcing effect from ChNF nano-networks as well as the formation of hydrogen bondings between gelatin and chitin moleculars. Therefore, with the highly transparent and improved mechanical properties, the prepared ChNF/gelatin nanocomposite films may offer promising and broad prospects in the field of food packaging and bio-medical industrials. [ABSTRACT FROM AUTHOR]

In order to prepare novel polyimides (PI) with high transparency and solubility in common solvents, three diamine monomers containing pyridine or methyl-substituted pyridine and cyclohexane, 1,1'-bis[4-(5-amino-2-pyridinoxy) phenyl]cyclohexane (IIIa), 1,1'-bis[4-(5-amino-3-methyl-2-pyridinoxy)phenyl]cyclohexane (IIIb), and 1,1'-bis[4-(5-amino2-methyl-6-pyridinoxy)phenyl]cyclohexane (IIIc), were synthesized and characterized. The diamine monomer (IIIa) was subsequently polymerized with 3,3',4,4'-oxydiphthalic anhydride, 4,4'-(hexafluoroisopropylidene)-diphthalic anhydride (6FDA) to obtain PIs, PI-1 and PI-2. Furthermore, PI-3 (IIIb/6FDA) and PI-4 (IIIc/6FDA) were prepared for structure -- property comparison studies. The structures of the resulting PIs were characterized by fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, and elemental analysis. The physical properties of the PI films were investigated by thermogravimetric analysis, differential scanning calorimetric analysis, dynamic mechanical analysis, and ultraviolet -- visible spectroscopy. In general, the PIs showed excellent thermal properties and good mechanical properties. Most had good solubility in polar organic solvents such as N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone (NMP), m-cresol, and even soluble in low boiling solvents such as tetrahydrofuran (THF) and CHCl3. The PI films also exhibited high optical transmittance of 94-97% at 500 nm and cut-off wavelength at 345-359 nm. In summary, the introduction of methyl, cyclohexane, and pyridine groups into the backbone was shown to improve the solubility and transparency of PI films. [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]

The scalable synthesis of highly transparent and robust sub-monolayers of Co3O4 nano-islands, which efficiently catalyze water oxidation, is reported. Rapid aerosol deposition of Co3O4 nanoparticles and thermally induced self-organization lead to an ultra-fine nano-island morphology with more than 94% light transmission at a wavelength of 500 nm. These transparent sub-monolayers demonstrate a remarkable mass-weighted water oxidation activity of 2070-2350 A gCo3O4−1 and per-metal turnover frequency of 0.38-0.62 s−1 at an overpotential of 400 mV in 1 m NaOH aqueous solution. This mixed valent cobalt oxide structure exhibits excellent long-term electrochemical and mechanical stability preserving the initial catalytic activity over more than 12 h of constant current electrolysis and 1000 consecutive voltammetric cycles. The potential of the Co3O4 nano-islands for photoelectrochemical water splitting has been demonstrated by incorporation of co-catalysts in GaN nanowire photoanodes. The Co3O4-GaN photoanodes reveal significantly reduced onset overpotentials, improved photoresponse and photostability compared to the bare GaN ones. These findings provide a highly performing catalyst structure and a scalable synthesis method for the engineering of efficient photoanodes for integrated solar water-splitting cells. [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]

To further increase the efficiency of multijunction thin-film silicon (TF-Si) solar cells, it is crucial for the front electrode to have a good transparency and conduction, to provide efficient light trapping for each subcell, and to ensure a suitable morphology for the growth of high-quality silicon layers. Here, we present the implementation of highly transparent modulated surface textured (MST) front electrodes as light-trapping structures in multijunction TF-Si solar cells. The MST substrates comprise a micro-textured glass, a thin layer of hydrogenated indium oxide (IOH), and a sub-micron nano-textured ZnO layer grown by low-pressure chemical vapor deposition (LPCVD ZnO). The bilayer IOH/LPCVD ZnO stack guarantees efficient light in-coupling and light trapping for the top amorphous silicon (a-Si:H) solar cell while minimizing the parasitic absorption losses. The crater-shaped micro-textured glass provides both efficient light trapping in the red and infrared wavelength range and a suitable morphology for the growth of high-quality nanocrystalline silicon (nc-Si:H) layers. Thanks to the efficient light trapping for the individual subcells and suitable morphology for the growth of high-quality silicon layers, multijunction solar cells deposited on MST substrates have a higher efficiency than those on single-textured state-of-the-art LPCVD ZnO substrates. Efficiencies of 14.8% (initial) and 12.5% (stable) have been achieved for a-Si:H/nc-Si:H tandem solar cells with the MST front electrode, surpassing efficiencies obtained on state-of-the-art LPCVD ZnO, thereby highlighting the high potential of MST front electrodes for high-efficiency multijunction solar cells. Copyright © 2015 John Wiley & Sons, Ltd. [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]

High-quality SnO2:Si films and SnO2:10 at.% Ga films were prepared by the solution method. The roughness of films is below 1.08 nm, and possess exceptional transparency (>75%) and decent semiconductor properties. Based on this, the SnO2:Si/SnO2: Ga homojunctions with different Si doping concentrations were prepared. It is found that the conductivity of the SnO2:Si thin film gradually increases, and the rectification characteristics of the homojunction are optimized with increasing Si doping content. The SnO2:15 at.% Si/SnO2:10 at.% Ga homogeneous junction has the best performance, the turn-on voltage is as low as 5.6 V, and it also exhibits good unidirectional conductivity. The photoresponse of the SnO2:15 at.% Si/SnO2:10 at.% Ga homojunction under the lights of red, yellow, and purple was explored respectively. The result shows that the device responds strongly to purple light. Compared with the test results in the dark environment, the device current increases by two orders, which is expected to be applied in the field of near-ultraviolet detection. [ABSTRACT FROM AUTHOR]

Environment-adaptable photonic-electronic-coupled devices can help overcome major challenges related to the extraction of highly specific angular information, such as human visual perception. However, a true implementation of such a device has rarely been investigated thus far. Herein, we provide an approach and demonstrate a proof-of-concept solid-state semiconductor-based highly transparent, optical-electrical-coupled, self-adaptive angular visual perception system that can fulfill the versatile criteria of the human vision system. Specifically, all of the primitive functions of visual perception, such as broad angular sensing, processing, and manifold memory storage, are demonstrated and comodulated using optical and electric pulses. This development represents an essential step forward in the fabrication of an environment-adaptable artificial angular perception framework with deep implications in the fields of optoelectronics, artificial eyes, and memory storage applications.

Solution-processable highly transparent and thickness-insensitive hybrid electron-transport layer (ETL) with enhanced electron-extraction and electron-transport properties for high-performance polymer solar cell was reported. With the incorporation of Cs 2 CO 3 into the poly[(9,9-bis(6'-((N,N-diethyl)-N-ethylammonium)-hexyl)-2,7-fluorene)-alt-1,4-diphenylsulfide]dibromide (PF6NPSBr) ETL, the power conversion efficiency (PCE) of resulted polymer solar cells (PSCs) was significantly enhanced due to the favorable interfacial contact, energy-level alignment, and thus facile electron transport in the PSC device. These organic-inorganic hybrid ETLs also exhibited high transparency and high electron mobility. All of these combined properties ensured us to design novel thickness-insensitive ETLs that avoid the parasitic absorption of ETL itself simultaneously. With the conventional device structure with poly{4,8-bis[5-(2-ethylhexyl)thiophen-2-yl]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophene-4,6-diyl} (PTB7-Th) as a donor and [6,6]-phenyl-C71-butyric acid methyl ester (PC 71 BM) as an acceptor, devices with hybrid ETLs exhibited PCE of 8.30-9.45% within a wide range of ETL thickness. A notable PCE of 10.78% was achieved with the thick active layer poly(2,5-thiophene-alt-5,5'-(5,10-bis(4-(2-octyldodecyl)thiophen-2-yl)naphtho[1,2-c:5,6-c']bis([1,2,5]thiadiazole)) (PTNT812):PC 71 BM. These findings indicated that doping alkali salt into the organic interfacial materials can be a promising strategy to design highly efficient and thickness-insensitive ETL, which may be suitable for large-area PSC modules device fabrication with roll-to-roll printing technique.