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An ultra-thin spiral diffractive lens (SDL) was fabricated by using focused ion beam milling on a fiber end-facet coated with a 100 nm thick Au film. Focusing vortex beams (FVBs) were successfully excited by the SDLs due to the coherent superposition of diffracted waves and their azimuth dependence of the phase accumulated from the spiral aperture to the beam axis. The polarization and phase characteristics of the FVBs were experimentally investigated. Results show that the input beams with various polarization states were converted to FVBs, whose polarization states were the same as those of the input beams. Furthermore, the focal length of the SDL and the in-tensity and phase distribution at the focus spot of the FVBs were numerically simulated by the FDTD method in the ultra-wide near-infrared waveband from 1300 nm to 1800 nm. The focal length was tuned from 21.8 μm to 14.7 μm, the intensity profiles exhibited a doughnut-like shape, and the vortex phase was converted throughout the broadband range. The devices are expected to be candidates for widespread applications including optical communications, optical imaging, and optical tweezers. [ABSTRACT FROM AUTHOR]

Temperature sensors play important roles in wide-spreading human activities. The non-contact method of using temperature sensors offers significant advantages but faces challenges in detection precision. In this work, a double-layer asymmetric terahertz (THz) metamaterial combined with phase transition oxide was proposed to realize non-contact temperature sensor with high sensitivity. The metamaterial exhibited band-stop filtering effects in the simulated transmission spectra. Temperature changes induced a reversible phase transition in VO2, resulting in altered conductivity. The numerical results indicated that the S21 parameter increases from −44.33 dB to −4.78 dB at a frequency of 1.22 THz as the conductivity of the VO2 film increases from 10 to 5000 S/m, achieving a modulation depth of 89%. In addition, the 86 nm thick VO2 film underwent a phase transition in the temperature range of 54.93 °C to 66.93 °C, achieving a sensitivity of 1.82 dB/°C for temperature sensing. This work provided great insights into the development of metamaterials based on high-precision temperature measurement. [ABSTRACT FROM AUTHOR]

This work investigates the endurance and performance of aluminum-doped zinc oxide (AZO) thin films fabricated on flexible polyethylene terephthalate (PET) substrates, providing new insights into their degradation linked to mechanical flexing and accelerated thermal cycling (ATC). The current study uniquely combines cyclic bending fatigue at 23 °C and 70 °C with ATC between 0 °C and 100 °C, simulating operational stresses in real-world environments, in contrast to previous research that has focused primarily on either isolated mechanical or thermal effects. The 425 nm thick films showed high transparency and conductivity, making them suitable materials for flexible electronics and optoelectronic devices. In this work, electrical resistivity, one of the most important performance parameters, was investigated after each mechanical or thermal cycle. The results indicate that mechanical cycling at high temperatures can drastically enhance the crack formation and electrical degradation, with an over 250% change in the electrical resistance (PCER) after 12,000 cycles at 70 °C and more than 300% after 500 thermal cycles. The highly deleterious effects of combined stressors on the structural integrity and electrical properties of AZO films are underlined by these observations. This study further suggests that the design of more robust AZO-based materials/coatings would contribute toward achieving better durability in flexible electronic applications. These findings also go hand in glove with the ninth goal of the United Nations' Sustainable Development Goals, specifically Target 9.5: Enhance Research and Upgrade Industrial Technologies. [ABSTRACT FROM AUTHOR]

This study examines copper thin films under tensile stress and their shape and percentage change in electrical resistance (PCER) as a function of applied strain. Copper films of 100 and 200 nm thickness were sputtered onto polyethylene terephthalate (PET) substrates and were then sequentially stretched to examine how film thickness affects strain-induced morphological changes and electrical resistance. A scanning electron microscope (SEM) was used to track crack patterns, and electrical resistance was monitored throughout tensile testing. Thinner films (100 nm) had quick crack initiation and propagation, leading to an increase in PCER under strain, while thicker films (200 nm) had more gradual morphological and electrical resistance changes. This differential reaction demonstrates the importance of film thickness in mechanical deformation and strain sensitivity, which could affect the design of flexible electronic devices that require mechanical durability and reliable electrical performance. These findings will help to optimize film thickness for stretchable sensors and wearable electronics to balance strain sensitivity and morphological degradation. This study will help designers and users of sensors, stretchable electronics, and other devices that require mechanical durability and electrical performance to understand the relationship between mechanical deformation and electrical properties in thin films. This paper aligns with the ninth goal of the United Nations Sustainable Development Goals, specifically Target 9.5: Enhance Research and Upgrade Industrial Technologies. [ABSTRACT FROM AUTHOR]

Wrinkling, creasing, and folding are frequent phenomena encountered in biological and man-made bilayers made by thin films bonded to thicker and softer substrates often containing fibers. Paradigmatic examples of the latter are the skin, the brain, and arterial walls, for which wiggly cross sections are detected. Although experimental investigations on corrugation of these and analog bilayers would greatly benefit from scaling laws for prompt comparison of the wrinkling features, neither are they available nor have systematic approaches yielding to such laws ever been provided before. This gap is filled in this paper, where a uniaxially compressed bilayer formed by a thin elastic film bonded on a hyperelastic fiber-reinforced substrate is considered. The force balance at the film–substrate interface is here analytically and numerically investigated for highly mismatched film–substrates. The onset of wrinkling is then characterized in terms of both the critical strain and its corresponding wavenumber. Inspired by the asymptotic laws available for neo-Hookean bilayers, the paper then provides a systematic way to achieve novel scaling laws for the wrinkling features for fiber-reinforced highly mismatched hyperelastic bilayers. Such novel scaling laws shed light on the key contributions defining the response of the bilayer, as it is characterized by a fiber-induced complex anisotropy. Results are compared with finite element analyses and also with outcomes of both existing linear models and available ad hoc scalings. Furthermore, the amplitude, the global maximum and minimum of ruga occurring under increasing compression spanning the wrinkling, period doubling, and folding regimes are also obtained. [ABSTRACT FROM AUTHOR]

Surface Phonon Polaritons (SPhPs) as an evanescent electromagnetic surface wave supports long propagation which readily surpasses the mean free path of classical heat carriers, e.g., phonons and electrons in solids. SPhPs have emerged as a promising candidate to dominate heat transfer in thin films. Polaritonic heat transfer has two distinct advantages: superior thermal conduction and a wide range of manipulation. Here, we study the upper limit of the thermal conductivity mediated by long-range polaritons in asymmetric surrounding media, where its surface effect overwhelms the volumetric one. The thin film structure strengthens the interactions of two surface waves at the top and bottom surfaces, and the asymmetric surrounding media makes an evanescent surface wave to further penetrate the free space with a higher refractive index, but it requires a fine tuning of asymmetric permittivity of the surrounding media to reach the upper limit of energy transmission efficiency near to the modal cut-off, where the transverse wavevector becomes zero. Both analytical and numerical simulations were introduced to investigate dispersion in asymmetric surrounding media and to model the thermal conductivity of glass thin films. Anomalously high thermal conductivity of 248 W/m-K was achieved with a 50 nm thick SiO2 film in asymmetric surrounding media, yet subtly dissimilar. [ABSTRACT FROM AUTHOR]

Nowadays metal oxide nanoparticles and transition metal dichalcogenides play a vital role in various areas like optical sensors, solar cells, energy storage devices, gas sensors and biomedical applications. In the current research work, we synthesized ZrSe2 nanoparticles by hydrothermal method. The ZrSe2 nanoparticles were synthesis using precursors such as ZrOCl2.8H2O and Na2SeO3.5H2O in the addition of surfactant cetyl trimethyl ammonia bromide CTAB and reductant hydrazine hydrate, respectively. By using synthesized ZrSe2 nanopowder thick films were developed on a glass substrate using the screen printing method. The structural properties of ZrSe2 powder were studied by X-ray diffraction (XRD). The X-ray diffraction analysis revealed that the hexagonal crystal structure and crystalline size were found to be 55.75 nm. The thick films of ZrSe2 were characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX). The surface morphological analysis of ZrSe2 nanostructured thick film shows hierarchical nanoparticles. The energy band gap of synthesized powder was calculated using a Tauc plot from UV-visible spectroscopy. The gas-sensing properties of ZrSe2 thick films were studied. The developed ZrSe2 thick films show maximum sensitivity and selectivity towards the ammonia NH3 gas at an operating temperature of 120 °C and the gas concentration was 500 ppm. The developed thick films show fast response and recovery time.Nowadays metal oxide nanoparticles and transition metal dichalcogenides play a vital role in various areas like optical sensors, solar cells, energy storage devices, gas sensors and biomedical applications. In the current research work, we synthesized ZrSe2 nanoparticles by hydrothermal method. The ZrSe2 nanoparticles were synthesis using precursors such as ZrOCl2.8H2O and Na2SeO3.5H2O in the addition of surfactant cetyl trimethyl ammonia bromide CTAB and reductant hydrazine hydrate, respectively. By using synthesized ZrSe2 nanopowder thick films were developed on a glass substrate using the screen printing method. The structural properties of ZrSe2 powder were studied by X-ray diffraction (XRD). The X-ray diffraction analysis revealed that the hexagonal crystal structure and crystalline size were found to be 55.75 nm. The thick films of ZrSe2 were characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX). The surface morphological analysis of ZrSe2 nanostructured thick film shows hierarchical nanoparticles. The energy band gap of synthesized powder was calculated using a Tauc plot from UV-visible spectroscopy. The gas-sensing properties of ZrSe2 thick films were studied. The developed ZrSe2 thick films show maximum sensitivity and selectivity towards the ammonia NH3 gas at an operating temperature of 120 °C and the gas concentration was 500 ppm. The developed thick films show fast response and recovery time.

The 20CrNi4Mo alloy with excellent high‐temperature stability is often used to manufacture low‐alloy steel piercing plugs, which are subject to harsh service conditions and usually fail due to severe wear. Repairing and remanufacturing failed piercing plugs not only extends the product's lifecycle but also has significant resource and environmental benefits. In this work, the feasibility of laser additive repair of failed piercing plugs using 20CrNi4Mo powder by selective laser melting technology is explored and the effect of preoxidation on the surface microstructure and mechanical properties of the repaired layer is investigated. The results show that the repaired layer has good metallurgical bonding with the substrate, and the densification reaches 99.8%. Compared with the substrate, the ultimate tensile strength and microhardness of the repaired layer increase by 88.97% and 70.68% to 1287 MPa and 380 HV, respectively. The oxide film exhibits a clear two‐layer, with the repair layer exhibiting a thicker oxide film. The average friction coefficient of the oxidized repair layer (0.263) is reduced compared with that of the oxidized substrate (0.382). This work provides a feasible and effective way to realize the repairing and remanufacturing of failed piercing plugs with enhanced surface mechanical properties. [ABSTRACT FROM AUTHOR]

Proton exchange membrane fuel cells (PEMFCs), which use hydrogen as fuel, present an eco-friendly alternative to internal combustion engines (ICEs) for powering low-to-heavy-duty vehicles and various devices. Despite their promise, PEMFCs must meet strict cost, performance, and durability standards to reach their full potential. A key challenge lies in optimizing the electrode, where a thin ionomer layer is responsible for proton conduction and binding catalyst particles to the electrode. Enhancing ion transport within these sub-μm thick films is critical to improving the oxygen reduction reaction (ORR) at the cathodes of PEMFCs. For the past 15 years, our research has targeted this limitation through a comprehensive "Unravel – Engineer – Design" approach. We first unraveled the behavior of ionomers, gaining deeper insights into both the average and distributed proton conduction properties within sub-μm thick films and at interfaces that mimic catalyst binder layers. Next, we engineered ionomer–substrate interfaces to gain control over interfacial makeup and boost proton conductivity, essential for PEMFC efficiency. Finally, we designed novel nature-derived or nature-inspired, fluorine-free ionomers to tackle the ion transport limitations seen in state-of-the-art ionomers under thin-film confinement. Some of these ionomers even pave the way to address cost and sustainability challenges in PEMFC materials. This feature article highlights our contributions and their importance in advancing PEMFCs and other sustainable energy conversion and storage technologies. [ABSTRACT FROM AUTHOR]

Due to its outstanding optical and electronic properties, molybdenum ditelluride (MoTe2) has become a highly regarded material for next-generation optoelectronics. This study presents a comprehensive, comparative analysis of thin (8 nm) and thick (30 nm) MoTe2-based photodetectors to elucidate the impact of thickness on device performance. A few layers of MoTe2 were exfoliated on a silicon dioxide (SiO2) dielectric substrate, and electrical contacts were constructed via EBL and thermal evaporation. The thin MoTe2-based device presented a maximum photoresponsivity of 1.2 A/W and detectivity of 4.32 × 108 Jones, compared to 1.0 A/W and 3.6 × 108 Jones for the thick MoTe2 device at 520 nm. Moreover, at 1064 nm, the thick MoTe2 device outperformed the thin device with a responsivity of 8.8 A/W and specific detectivity of 3.19 × 109 Jones. Both devices demonstrated n-type behavior, with linear output curves representing decent ohmic contact amongst the MoTe2 and Au/Cr electrodes. The enhanced performance of the thin MoTe2 device at 520 nm is attributed to improved carrier dynamics resulting from effective electric field penetration. In comparison, the superior performance of the thick device at 1064 nm is due to sufficient absorption in the near-infrared range. These findings highlight the importance of thickness control in designing high-performance MoTe2-based photodetectors and position MoTe2 as a highly suitable material for next-generation optoelectronics. [ABSTRACT FROM AUTHOR]

(1-x) (Na 0.2 K 0.8)NbO 3 -xSrTiO 3 [(1-x) (N 0.2 K 0.8)N-xST] ceramics with a homogeneous perovskite structure were well-sintered in the range of 1080–1160 °C. The 0.9(N 0.2 K 0.8)N-0.1ST ceramic was found to have a temperature-stable dielectric constant (ε r) that complies with the X9R multilayer ceramic capacitor (MLCC) requirement. The temperature stability of the ε r value was also investigated for the 0.9(N 1-z K z)N-0.1ST ceramics (0.0 ≤ z ≤ 1.0). The results indicated that as z (or K+ ions) increased, the Curie temperature (T C) decreased, and its peak broadened. The broadening of the T C peak was attributed to the development of the relaxor property owing to the tilting of the NbO 6 octahedra. The 0.9(N 1-z K z)N-0.1ST ceramics (0.7 ≤ z ≤ 1.0) exhibited a temperature-independent ε r value, thus fulfilling the X9R MLCC requirement because of the broad T C peak. The MLCC fabricated from 0.9(N 0.2 K 0.8)N-0.1ST thick films complied with the X9R MLCC requirement with excellent capacitance stability under the supplied electric field. Hence, 0.9(N 1-z K z)N-0.1ST ceramics (0.7 ≤ z ≤ 1.0) are good candidates for X9R MLCCs. [ABSTRACT FROM AUTHOR]

In response to the toxic heavy metal absorbers in perovskite solar cells (PSCs), this work focuses on the development of an environmentally friendly simple solution‐processed infrared (IR) absorber. In this work, a simple solution‐crystallized IR‐absorbing AgBiS2 film is reported by spin‐coating silver, bismuth nitrates, and thiourea dissolved in dimethylformamide (DMF) to produce thick AgBiS2 film. Extensive optimization of the precursor concentrations thicknesses and conductive substrates used allow for obtaining 250 nm AgBiS2 film with different crystal sizes. When applied as an absorber in solar cells, solution‐crystalized AgBiS2 thick film delivers an extraordinarily high current density of over 31 mA cm−2. The devices show high stability under continuous 100 mW cm−2 illumination and when stored in the dark for more than six months. When the AgBiS2 layer is fabricated in a gradient fashion combining one layer of 0.25 m and three layers of 0.5 m precursor concentrations, the efficiency of 5.15% is registered which is the highest reported for the simple solution‐crystallized AgBiS2 films. [ABSTRACT FROM AUTHOR]

The electrophysical properties of nanostructured MgAl2O4 ceramics sintered at 1300 °C for 5 h, as well as thick films were obtained and investigated. The study of adsorption-desorption cycles was carried out after sintering and aging test. It is shown that ceramic has a sensitivity to humidity in the range of 25–95% with minimal hysteresis of the characteristic in adsorption-desorption cycles, which can be eliminated after the aging test. Thick films based on it are characterized by hysteresis and loss of sensitivity at low values of relative humidity, which is caused by the clogging of small nanopores. [ABSTRACT FROM AUTHOR]

A number of chalcogenides show a remarkable portfolio of properties, which enables a plethora of applications including thermoelectric power generation and phase change material (PCM)‐based information storage. PCMs exhibit fast and reversible switching between two (typically, amorphous and crystalline) states, characterized by different optical and electrical properties. In the last decade, textured chalcogenide thin films have been investigated to develop a better understanding of structure – property relationships, improve material performance and understand how these properties change upon reducing film thickness. In this review, the present knowledge concerning the textured growth is summarized, focusing on films of GeTe, Sb2Te3, and GeSbTe compounds. In particular, the impact of different deposition methods, substrate surface modifications, and methods to influence film formation is reviewed. In the second part of this review, confinement effects are discussed. Surprisingly pronounced changes in atomic arrangement, that affect film properties, and device performance are presented. These changes are attributed to the unconventional bonding mechanism in these chalcogenides coined metavalent bonding, which is trongly affected by the confinement. Bonding becomes covalent‐like in the two‐dimensional limit, whereas Metavalent Bonding emerges for thicker films, where electron delocalization is increased This explains the pronounced property changes with film thickness. [ABSTRACT FROM AUTHOR]

The immobilization of suspension catalysts in flexible, fibrillated films offers a promising solution to the mass transfer limitations often encountered in three-phase hydrogenation reactions. This study investigates the catalytic performance and mass transfer properties of fibrillated films in the hydrogenation of nitrobenzene to aniline, comparing them to free-flowing powdered catalysts. Fibrillated films were prepared from Pd/C catalysts with varying thicknesses (100–400 µm), and their performance was evaluated through kinetic studies in both batch reactors and microreactors. The specific activity of the films was significantly influenced by film thickness with thinner films demonstrating lower mass transfer limitations. However, mass transfer limitations were observed in thicker films, prompting the development of alternative film designs, including enhanced macro-porous films and sandwich structures. These modifications successfully minimized diffusion limitations, achieving similar specific activity to the powder catalysts while maintaining the mechanical stability of the films. This work demonstrates the feasibility of using fibrillated films for continuous catalytic processes and highlights their potential for efficient catalyst reuse, avoiding filtration steps and enhancing process sustainability. Furthermore, while PTFE remains indispensable for producing such films due to its mechanical and thermal stability, ongoing research focuses on identifying more environmentally friendly alternatives without compromising performance. [ABSTRACT FROM AUTHOR]

This study investigates the potential of hydrolyzed bacterial cellulose (hBC) for UV radiation protection. BC membranes are produced under static conditions by Komagataeibacter sucrofermentans, purified, mechanically shredded, and hydrolyzed. As a result, hBC exhibits colloidal properties at various concentrations (0.34 – 11 mg ml−1). With a water-holding capacity of 89.1% ± 0.341, hBC forms a 3.65 μm thick transparent film with an approximate density of 7 μg per mm2. In Scanning Electron Microscopy (SEM) analysis, the lengths of filamentous BC particles were between 50 and 300 nm, while the lengths of rod-like nanocrystalline cellulose were between 400 and 1500 µm. According to dynamic light scattering (DLS) result, 88% of the particles were approximately 1 µm long. The zeta potential was −25.13 ± 0.65 mV, hBC showed thixotropic behaviour, and its crystallinity was 92. hBC and its films exhibited barrier properties to UV radiation (190–400 nm). The highest UV absorbance (almost 100%) for all UV regions (UV-A, UV-B and UV-C) of hBC in colloidal form is at a concentration of 11 mg ml−1. At most, the UV transmittance of all UV regions of the hBC films was 16%. Sun protective factor (SPF) values of colloidal and film forms of the hBC at a concentration of 11 mg ml−1 and 212 µg/mm2 were 29 and 12, respectively. hBC was not cytotoxic on mouse fibroblast L929 and human keratinocyte (HaCaT) cells. In conclusion, hBC can be an alternative UV radiation protector and thickening agent. This study represents the first report on the UV barrier property of hBC for aqueous formulations. [ABSTRACT FROM AUTHOR]

In response to the toxic heavy metal absorbers in perovskite solar cells (PSCs), this work focuses on the development of an environmentally friendly simple solution‐processed infrared (IR) absorber. In this work, a simple solution‐crystallized IR‐absorbing AgBiS2 film is reported by spin‐coating silver, bismuth nitrates, and thiourea dissolved in dimethylformamide (DMF) to produce thick AgBiS2 film. Extensive optimization of the precursor concentrations thicknesses and conductive substrates used allow for obtaining 250 nm AgBiS2 film with different crystal sizes. When applied as an absorber in solar cells, solution‐crystalized AgBiS2 thick film delivers an extraordinarily high current density of over 31 mA cm−2. The devices show high stability under continuous 100 mW cm−2 illumination and when stored in the dark for more than six months. When the AgBiS2 layer is fabricated in a gradient fashion combining one layer of 0.25 m and three layers of 0.5 m precursor concentrations, the efficiency of 5.15% is registered which is the highest reported for the simple solution‐crystallized AgBiS2 films. [ABSTRACT FROM AUTHOR]

The realization of large‐area high‐quality perovskite thick films under an atmospheric environment without humidity control is confronting an urgent challenge for the applications in X‐ray detection and imaging. A spray‐coating method with air as the gas carrier is employed to achieve large‐area perovskite thick films for X‐ray flat‐panel detection applications. To further improve the quality of the thick films, the 10 µm‐thick CsPbIBr2 films with (100)‐preferred orientation, low trap density (7.1 × 1012 cm−3) and high resistivity corresponding to low dark current (3.2 × 10−9 A) are prepared via dual‐additive‐assisted (NH4SCN and L‐α‐phosphatidylcholine (LP)) solution strategy under atmospheric environment with relative humidity of 60% (60% RH). Thus, the metal‐semiconductor‐metal‐structured (Au/CsPbIBr2/Au) transverse X‐ray detection device under 40 KeV X‐ray irradiation possesses a high sensitivity up to 1420 µC Gyair−1 cm−2 under a weak electric field of 18 V mm−1 and a low dose rate of 3.3 µGyair s−1 that is lower than a dose rate of ≈5.5 µGyair s−1 required for routine medical diagnosis. Strikingly, the unencapsulated device maintains 80% (1120 µC Gyair−1 cm−2) of the original sensitivity after 1000 h under the atmospheric environment with 45–55% RH. These results pave the way for the practical applications of perovskite thick films in X‐ray medical detection and imaging. [ABSTRACT FROM AUTHOR]

Self‐powered near‐infrared (NIR) photodetectors are essential for surveillance systems, sensing in IoT electronics, facial recognition, health monitoring, optical communication networks, night vision, and biomedical imaging. However, silicon commercial detectors need external power to operate and cooling to suppress large dark currents. This work demonstrates a new class of CMOS‐compatible self‐powered NIR photodetector based on ferroelectric 5‐nm thick ZrO2 films which do not require cooling and therefore have two key advantages over Si, and at the same time have comparable performance metrics. At room‐temperature, under 940 nm wavelength illumination (1.4 mW cm−2 power density, 10 Hz repetition rate), and without any power applied, fast rise and fall times of ≈2 and 4 µs, respectively, are achieved in Al/Si/SiOx/ZrO2/ITO devices, along with responsivity, detectivity and sensitivity values of up to ≈3.4 A W−1, 1.2 × 1010 Jones and 4.2 × 103, respectively, far exceeding all other emerging self‐powered systems. Furthermore, dual‐band NIR detection is shown for different NIR wavelengths, proof‐of‐concept feasibility being demonstrated for the smart identification of NIR targets. Therefore, it is demonstrated, for the first time, that coupling together the pyroelectric effect, the photovoltaic effect, and the ferroelectric effect is a novel method to significantly enhance the performance of CMOS‐compatible ZrO2‐based self‐powered photodetectors in the NIR region. [ABSTRACT FROM AUTHOR]

Interest in self-cleaning coatings is rising due to their potential to enhance comfort and quality of life in polluted urban environments, driving the search for materials with optimal physical properties. Convergent with this goal, this study investigates the wetting properties and photo-catalytic efficiency of reticulated TiO 2 layers. It shows that these properties are significantly influenced by the topographical characteristics of the TiO 2 surface, which can be precisely controlled through variations in pulverization pressure and low-temperature post-annealing treatments. Post-deposition annealing of the TiO 2 layers achieves 100 % self-cleaning efficiency for both thick and thin films, with optical transmission ranging from approximately 60 %–80 % in the visible spectrum. Additionally, the TiO 2 layers exhibited promising capabilities for eliminating pathogenic microorganisms and disinfecting surfaces. The underlying causal factors of these remarkable and technologically promising surface features are explored and discussed. [ABSTRACT FROM AUTHOR]

Bifacial perovskite solar cells (PSCs) possess a dual light‐absorbing structure, which enables higher power output at lower additional costs. However, the replacement of metal electrodes with transparent ones leads to serious light loss, necessitating a thicker perovskite layer to compensate for this drawback. In this study, the impact of different rubidium halide (RbCl, RbBr, and RbI) additives is systematically investigated on precursor solubility and the quality of micron‐sized perovskite thick films prepared using a two‐step method. It is observed that RbCl exhibited the strongest interactions with PbI2, enhancing its solubility and leading to the formation of multihole PbI2 films that promote subsequent crystallization of thick perovskite film. Additionally, the RbCl‐based perovskite film demonstrates a narrowed bandgap attributed to the formation of a‐FAPbI3. Consequently, the short‐circuit current density (Jsc) and open‐circuit voltage (Voc) in the RbCl‐based bifacial PSCs are simultaneously enhanced, and a record efficiency of 20.86% (21.04% certified) is also obtained among n‐i‐p bifacial PSCs, exhibiting an ≈80% bifaciality and a power generation density (PGD) exceeding 24 mW cm−2 with a reflectivity value of 0.2. More importantly, the optimized device does not show any performance degradation after continuous illumination under 1sun for 1000 h. [ABSTRACT FROM AUTHOR]

Alumina, as a pivotal ceramic material extensively utilized in contemporary applications, the surface modification and enhancement of tribological properties are crucial. In this study, reactive magnetron sputtering was employed to deposit Ti, Si co-doped hydrogen-free (TiSi/a-C), and hydrogenated amorphous carbon films (TiSi/a-C:H) with a thickness exceeding 7 μm onto the surface of alumina ceramic substrates. Utilizing the design of the film structure, the difficulty of film-substrate adhesion was resolved by controlling the deposition time to influence the growth rate of the film, thereby enabling the reliable fabrication of thick films. The adhesion of the TiSi/a-C film exhibits the highest value, with an Lc1 value of 36.7 N. The hardness of the TiSi/a-C:H reaches a maximum of 15.2 GPa, and the hardness is closely correlated with the reaction gas utilized during its depositional process. The wear rate of amorphous carbon film decreases by 34 times compared to alumina substrate. During the dissociation of CH 4 at a high hydrogen-to-carbon ratio, more hydrogen atoms are involved in the chemical reaction. The introduction of hydrogen elevates the H/E and sp3/sp2 ratios within the film, thereby favoring the generation of low-friction surfaces and refining the tribological performance of alumina ceramics. [ABSTRACT FROM AUTHOR]

This study investigates Co 40 Fe 40 Dy 20 thin films on glass substrates with thicknesses ranging from 10 nm to 50 nm under four conditions: as-deposited, annealed at 100 °C, 200 °C, and 300 °C. X-ray diffraction (XRD) confirms film amorphousness due to limited thermal energy. Maximum low-frequency alternate-current magnetic susceptibility (χ ac) is observed at thicker films and higher annealing temperatures, with films at 300 °C showing the highest value 0.41. Annealing at 200 °C yields exceptional properties high saturation magnetization (M s) 748 emu/cm³ and low coercivity (Hc) 10 Oe, though Ms decreases at 300 °C due to thermal effects. Electrical resistivity and sheet resistance decrease with thickness and annealing, enhancing carrier transport. Transmittance (%) decreases notably with increased thickness, attributed to thickness and interface effects. Variations in surface roughness from annealing affect properties, with smoother surfaces improving carrier conductivity but reducing optical transparency. Overall, Co 40 Fe 40 Dy 20 exhibits excellent soft magnetic properties suitable for various applications. [ABSTRACT FROM AUTHOR]

he flexoelectric energy harvesters face such challenges as the monotonous energy harvesting mode, the low electromechanical coupling coefficient, the only prominent effect on microscales, and the limited energy conversion efficiency on macroscales. The electret, as a dielectric material with embedded charges, exhibits significant flexoelectric-like responses induced by non-uniform deformation. The crumpled film in complex bidirectional contraction, provides a novel efficient energy harvesting approach due to high strain gradients on macroscales. Herein the strong macroscopic electromechanical coupling properties of electrets were combined with the advantageous high strain gradients of crumpling, to establish a deformation theory for crumpled flexoelectret films. Based on this model, the flexoelectric-like responses and energy harvesting characteristics of crumpled flexoelectret films were analyzed for different charge densities, supporting cup radii, film thicknesses, and scales. The results indicate that, for a 1 mm thick flexoelectret film, the effective flexoelectric-like intensity is 2 orders higher than that of the intrinsic flexoelectric effect of the pure PDMS film, with the charge density q=-0.2 mC·m-2. [ABSTRACT FROM AUTHOR]

This work demonstrates the fabrication, characterization, and energy storage capacity of high calcium-doped strontium titanate thick films (Sr0.60Ca0.40TiO3) for the first time. The thick films were fabricated using the screen-printing technique and densified using uniaxial pressing. The effect of densification on the structural, morphological, and surface chemical compositional of the materials was studied. The densified thick film revealed a notable frequency stability of dielectric permittivity (ε′) ≈ 198 with a low dielectric loss tangent (tanδ) in the order of 10− 3 between 100 Hz and 1 MHz and was characterized by slim P-E loops signifying its paraelectric nature. A high energy recovery density (Ue) of 4.1 J/cm3 and a high energy efficiency of 96% were simultaneously reached. [ABSTRACT FROM AUTHOR]

Photon‐pair generation based on optical parametric down‐conversion has attracted for the application as a light source for quantum information. Highly efficient wavelength‐conversion devices require a polarity‐inversion structure when using nitride semiconductors. A transverse quasi‐phase‐matching (QPM) polarity‐inverted GaN bilayer channel waveguide device is suitable for efficient wavelength conversion. This study designed a cross‐section device to satisfy the modal dispersion phase‐matching condition between the TM02 mode pump light and the TM00 mode signal/idler light. Moreover, an AlN oxidation interlayer fabricates the Ga‐polar/N‐polar (+c/−c) GaN layers via metalorganic vapor‐phase epitaxy (MOVPE). A 145 nm thick film layer with a macro‐step‐free surface is grown by optimizing the −c‐GaN growth conditions and reducing the substrate off‐angle to 0.2°. Next, the AlN layer is oxidized in an electric furnace and MOVPE is used to regrow a 1500 nm thick +c‐GaN layer. A macrosteps‐free surface can be achieved by reducing the off‐angle to 0.2° and optimizing the −c‐GaN growth conditions to avoid hillock formation. These results pave the way for improving the efficiency of GaN transverse QPM wavelength‐conversion devices. [ABSTRACT FROM AUTHOR]

Radiative cooling, an emerging technology that reflects sunlight and emits radiation into outer space, has gained much attention due to its energy-efficient nature and broad applicability in buildings, photovoltaic cells, and vehicles. This study focused on fabricating SiO2-polymethyl methacrylate (PMMA) and TiO2-SiO2-PMMA thick films via the blade-coating method. The investigation aimed to improve cooling performance by adding TiO2 particles to increase the coverage area and utilize the TiO2 reflectance ability. The characterizations of the emissivity/absorptivity, solar reflectance, and microstructure of the thick films were conducted by using ultraviolet–visible/near-infrared (UV-Vis/NIR) diffuse reflection spectroscopy and scanning electron microscopy, respectively. Experimental results revealed that the maximum temperature drops of approximately 9.4 and 9.8 °C were achieved during the daytime period for SiO2-PMMA and TiO2-SiO2-PMMA thick films. The total solar radiation reflectivity increased from 71.7 to 75.6% for SiO2-PMMA radiative cooling thick films after adding TiO2. These findings underscored the potential of TiO2-SiO2-PMMA thick films in advancing radiative cooling technology and cooling capabilities across various applications. [ABSTRACT FROM AUTHOR]

In the field of modern optical computing and communication, optical bistability plays a crucial role. With a weak third-order nonlinear coefficient, low switch thresholds of optical bistability from Si-based nanophotonic structures remain a challenge. In this work, a metasurface consisting of silicon nanostrip arrays placed on the optically thick silver film is proposed. The light–matter interaction is enhanced by mirror-inducing the magnetic anapole states (MASs) and asymmetrically optimizing its silicon nanostrip. Numerical results show that the average enhancement factor (EF) of an electric field can be greatly enhanced to be 1524.8. Moreover, the optical bistability of the proposed metasurface achieves the thresholds of ION-OFF and IOFF-ON of 8.5 MW/cm2 and 7.1 MW/cm2, respectively, which is the lowest threshold when compared to the previous works based on silicon nanostructures. The angular dependance of the bistability performance is also investigated. This work facilitates the proposed hybrid metasurface in the fields of miniaturized all-optical switches and modulators, which are key components in optical computing and communication. [ABSTRACT FROM AUTHOR]

The purpose of this study was to prepare Pickering emulsions stabilized by waste jujube kernel cellulose nanocrystals (CNC) using composite essential oils (EOs) (i.e., cinnamon essential oil [CIN] combined with clove essential oil [CL]). The Pickering emulsions were blended with chitosan (CS) to generate a composite film (CS/CNC/EOs Pickering emulsions). We evaluated the mechanical properties, barrier properties, and microstructures of CS/CNC/EOs bio-based packaging films containing different concentrations of EOs. In addition, the fresh-keeping effects of the composite membranes on beef sausages were evaluated over a 12-day storage period. Notably, the EOs exhibited good compatibility with CS. With the increase in the EOs concentration, the droplet size increased, the composite films became thicker, the elongation at break decreased, the tensile strength increased, and the water vapor permeability decreased. When the composite films were used for preserving beef sausages, the antioxidant and antibacterial activity of the membranes improved as the concentration of EOs increased, effectively prolonging the shelf life of the sausages. Composite membranes with an EOs concentration of 2% exerted the best fresh-keeping effects. Overall, owing to their antioxidant and antimicrobial properties, the bio-based composite films prepared using CS/CNC/EOs Pickering emulsions demonstrated immense potential for application in the packaging of meat products. [ABSTRACT FROM AUTHOR]

The microstructure of aluminum thin films, including the grain morphology and surface roughness, are key parameters for improving the thermal or electrical properties and optical reflectance of films. The first step in optimizing these parameters is a thorough understanding of the grain growth mechanisms and film structure. To investigate these issues, thin aluminum films with thicknesses ranging from 25 to 280 nm were coated on SiOx/Si substrates at ambient temperature under high-vacuum conditions and a low argon pressure of 3 × 10−3 mbar (0.3 Pa) using the radio frequency magnetron sputtering method. Quantitative analyses of the surface roughness and nanograin characteristics were conducted using atomic force microscopy (AFM), transmission electron microscopy (TEM), and X-ray diffraction. Changes in specular reflectance were measured using ultraviolet–visible and near-infrared spectroscopy. The low roughness values obtained from the AFM images resulted in high film reflectivity, even for thicker films. TEM and AFM results indicate monomodal, randomly oriented grain growth without a distinct columnar or spherical morphology. Using TEM cross-sectional images and the dependence of the grain size on the film thickness, we propose a grain growth mechanism based on the diffusion mobility of aluminum atoms through grain boundaries. [ABSTRACT FROM AUTHOR]

In this novel study, BaCe 0.9 Y 0.1 O 3– δ , BaCe 0. 9 Eu 0.1 O 3– δ , BaCe 0.9 Nd 0.1 O 3– δ , and BaCe 0.9 Dy 0.1 O 3– δ powders were synthesized by the self-combustion method and processed into thick porous films (60–70 % porosity) to investigate the water vapor sensing properties in the 400–700 °C temperature range. All samples showed a stable response value to water vapor in the whole temperature range, expressed as impedance ratio in dry and wet argon (Z dryAr / Z wetAr), and were able to detect 0.03 vol% of water vapor at 550 °C within the impedance range of 103 Ω at 100 Hz. The response values increased with the partial pressure of water and decreased with the temperature, whereas the maximal value of 3.41 reached the BaCe 0.9 Eu 0.1 O 3– δ sample at 550 °C and p (H 2 O) = 4.28 kPa. The average response time was several seconds and only slightly changed with the material type and experimental conditions. The recovery time depended on temperature and the Z dryAr / Z wetAr ratio, whereas the increase in the gas flow rate from 100 cm3/min to 200 cm3/min significantly reduced the recovery time for the BaCe 0.9 Eu 0.1 O 3– δ sample from 230 s to 55 s at 550 °C and p (H 2 O) = 2.14 kPa. All the samples exhibited stability and a high degree of reversibility after multiple exchanges of wet and dry atmospheres at different temperatures. Yet, their tendency to deteriorate in the presence of CO 2 might challenge a potential application in aggressive environments. [ABSTRACT FROM AUTHOR]

We report on metalorganic chemical vapor deposition (MOCVD) growth of controllably Si-doped 4.5 μm thick β-Ga2O3 films with electron concentrations in the 1015 cm−3 range and record-high room temperature Hall electron mobilities of up to 200 cm2/Vs, reaching the predicted theoretical maximum room temperature phonon scattering-limited mobility value for β-Ga2O3. Growth of the homoepitaxial films was performed on Fe-doped (010) β-Ga2O3 substrates at a growth rate of 1.9 μm/h using TEGa as the Gallium precursor. To probe the background electron concentration, an unintentionally doped film was grown with a Hall concentration of 3.43 × 1015 cm−3 and Hall mobility of 196 cm2/Vs. Growth of intentionally Si-doped films was accomplished by fixing all growth conditions and varying only the silane flow, with controllable Hall electron concentrations ranging from 4.38 × 1015 to 8.30 × 1015 cm−3 and exceptional Hall mobilities ranging from 194 to 200 cm2/Vs demonstrated. C-V measurements showed a flat charge profile with the ND+–NA− values correlating well with the Hall-measured electron concentration in the films. SIMS measurements showed the silicon atomic concentration matched the Hall electron concentration with carbon and hydrogen below detection limit in the films. The Hall, C-V, and SIMS data indicate the growth of high-quality 4.5 μm thick β-Ga2O3 films and controllable doping into the mid 1015 cm−3 range. These results demonstrate MOCVD growth of electronics grade record-high mobility, low carrier density, and thick β-Ga2O3 drift layers for next-generation vertical β-Ga2O3 power devices. [ABSTRACT FROM AUTHOR]

Insertion storage in battery electrodes and supercapacitive storage are typically considered to be independent phenomena and thus are dealt with in separate scientific communities. Using tailored experiments on titanium oxide thin films of various thicknesses, we demonstrate the simultaneous occurrence of both processes. For the interpretation of the entire storage profile encompassing both contributions, the (free) energies of the charge carriers in the mixed conductor and the neighboring phase are the only materials parameters required. The experimental results enable no less than a unification of insertion and supercapacitive storage, the first being dominant for thick films, the latter for thin films or negligible electronic conductivity. Therefore, the size of the storage medium and the nature of the current collecting phases can be used to tune power density versus energy density. [ABSTRACT FROM AUTHOR]

The tantalum oxide film was fabricated using an anodization process in a 0.5M H 2 SO 4 electrolyte. The evolution and corrosion resistance mechanism of anodized film on the Ta surface has been investigated by experiments and theoretical calculations. The results indicate that the sample with an anodic oxidation voltage of 20V and an anodic oxidation time of 60 min (Ta 20-60) exhibits the thickest oxidation film, measuring 360.00 nm and comprising an outer porous layer and an inner dense layer. Ta 20-60 demonstrates the highest E corr value of 0.009 V and the lowest I corr value of 0.879 μA cm−2, with a minimal density of point defects at 1.24 × 1019 cm−3, which imparts superior corrosion resistance. The calculation result shows that the growth rate of Ta anodic oxidation film is controlled by the diffusion and migration of vacancy defects. The O atom passes through one bridge site from the tetrahedral gap to another tetrahedral gap (Path 1) on the complete (110) surface has a low diffusion barrier of 0.470 eV and the shortest diffusion path of 2.04 Å, which is the most favorable path for the diffusion of O atoms. This paper offers a fresh perspective on the corrosion resistance of tantalum while furnishing guidance for improving Ta oxide film performance. [ABSTRACT FROM AUTHOR]

Nanocrystal (NC)-based devices suffer from a trade-off between absorption, pushing for thicker films, and charge conduction that is only efficient over a few NC sizes. Therefore, the design of detectors based on NCs strongly benefits from the introduction of optical resonators that engineer the light–matter coupling. Traditionally, the design of such a cavity relies on analytic scaling rules. However, the design becomes far more complex when multiple resonances are targeted, requiring alternative design strategies. In this study, we explore how infrared nanocrystals can be coupled to a guided mode resonator to achieve a broadband enhancement of absorption. A genetic algorithm is used to systematically investigate how geometric factors can be tuned to increase the absorption × bandwidth product. In comparison to the pristine film, a significant increase in absorption was demonstrated across the targeted spectral range (1–2.5 μm). The detector based on the design metasurface exhibited high detectivity (2 × 1010 Jones @ 200 K) and fast time response (18 ns). [ABSTRACT FROM AUTHOR]

Aramid copolymers have garnered significant interest due to their potential applications in extreme environments such as the aerospace, defense, and automotive industries. Recent developments in aramid copolymers have moved beyond their traditional use in high-strength, high-temperature resistant fibers. There is now a demand for new polymers that can easily be processed into thin films for applications such as electrical insulation films and membranes, utilizing the inherent properties of aramid copolymers. In this work, we demonstrate two novel aramid copolymers that are capable of polymerizing in polar organic solvents with a high degree of polymerization, achieved by incorporating flexible bis(4-aminophenoxy) benzene moieties into the chain backbone. The synthesized MBAB-aramid and PBAB-aramid have enabled the fabrication of exceptionally thin, clear films, with an average molecular weight exceeding 150 kDa and a thickness ranging from 3 to 10 μm. The dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) reveal that the thin films of MBAB-aramid and PBAB-aramid exhibited glass transition temperatures of 270.1 °C and 292.7 °C, respectively, and thermal decomposition temperatures of 449.6 °C and 465.5 °C, respectively. The mechanical tensile analysis of the 5 μm thick films confirmed that the tensile strengths, with elongation at break, are 107.1 MPa (50.7%) for MBAB-aramid and 113.5 MPa (58.4%) for PBAB-aramid, respectively. The thermal and mechanical properties consistently differ between the two polymers, which is attributed to variations in the linearity of the polymer structures and the resulting differences in the density of intermolecular hydrogen bonding and pi-pi interactions. The resulting high-strength, ultra-thin aramid materials offer numerous potential applications in thin films, membranes, and functional coatings across various industries. [ABSTRACT FROM AUTHOR]

Polymer-derived ceramics (PDCs) find extensive applications as sensitive materials in in-situ thin/thick film sensors (TFSs) co-fabricated with components. However, the prolonged high-temperature sintering steps of PDCs inevitably lead to severe thermal damage to their co-sintered substrates. In this study, we employed an ultrafast high-temperature sintering (UHS) method, achieving rapid sintering of preceramic polymer slurry sensitive films in just a few minutes. Through direct ink writing technology, we patterned the preceramic polymer slurry, followed by UHS to prepare high-temperature ITO/SiCN TFSs. UHS-ITO/SiCN exhibited high sensitivity of microstructure, composition, and electrical characteristics to UHS parameters. The obtained ITO/SiCN resistance grid showed high electrical conductivity (706.89 S m−1 at room temperature), highly dense surface structure and excellent oxidation resistance. In an air atmosphere, the resistance drift rate of the resistance grid at 900 °C was only 0.54 %·h−1 without any protective layers. Finally, we fabricated an ITO/SiCN heat flux sensor with high sensitivity (78.75 mV/(kW·m−2)), a wide range (94.8 kW m−2), and excellent repeatability. This work has the potential to expand the application of UHS in the manufacturing of novel in-situ TFSs integrated with components. [ABSTRACT FROM AUTHOR]

Due to its superior reliability and performance, thick film technology is extensively employed in various applications, including automotive electronics, consumer electronics, communication engineering, and aerospace. However, a challenge arises from the mutual diffusion during the electronic paste production process, which leads to a decline in insulation performance and hinders the production of three-dimensional equipment. Inspired by the principles of low-temperature co-fired ceramic technology, a multi-layered ceramic structure has been successfully bonded using thick film technology by introducing a borosilicate glass-ceramics layer. To further enhance the properties of this multi-layered ceramic structure, approximately 8 wt% SiO 2 was incorporated into the borosilicate glass-ceramics. This addition effectively inhibits silver diffusion and reduces the diffusion depth within the glass-ceramic film. The key mechanisms behind this improvement are the increased activation energy for crystallization, resulting in a slower crystallization rate due to the addition of SiO 2. Moreover, the multi-layered ceramic with a sandwich structure exhibits remarkable properties. Notably, the dielectric strength of this system has been significantly enhanced to 13.9 kV/mm, accompanied by a high adhesion strength of 790 N. These enhanced properties of the optimized system indicate promising characteristics for multi-layer circuit applications. [ABSTRACT FROM AUTHOR]

Hydrogen sensors are important in a hydrogen‐driven society to prevent explosions caused by hydrogen leaks into the atmosphere. In previous studies, resistive hydrogen sensors on polymer films have metal oxide nanostructures decorated with novel metals that enable good responses at room temperature. However, the in situ growth process of sensing nanostructures has the disadvantage of ineffective fabrication, particularly when preparing a thick catalyst layer to produce reliable readouts from the catalytic hydrogen combustion. This work presents a catalytic combustion hydrogen sensor with a thick catalyst layer anchored in a UV resin layer on polyimide film. Catalyst anchoring channels are made by UV imprinting with a glass mold. The sensor consists of a sensing electrode and a microheater, both made of Au within an area of 1.2 mm diameter. UV imprinting produces a UV resin layer of 27 µm thick and catalyst anchoring channels of 14 µm deep and 20–30 µm wide, which are filled with Pt/TiO2 as a catalyst. The sensing response is 7.9% for 1% H2 under ambient conditions, and the detection range is 0.1–3% H2. The UV‐resin microstructures can effectively retain a thick catalyst layer to enhance sensitivity, and their low thermal conductivity reduces heat loss. [ABSTRACT FROM AUTHOR]

Metal halide perovskites are revolutionizing X‐ray detection through a combination of low cost, solution processing, favorable optoelectronic properties, and high stopping power for high‐energy ionizing radiation. While perovskite single crystals and polycrystalline wafers are considered direct X‐ray converters, most medical X‐ray applications are based on scintillators that shift high‐energy radiation into the visible. Several materials are on the market, but demonstrations based on CsPbBr3 nanocrystals, possibly embedded in a matrix material or combined with organic molecules as luminescent species, highlight their competitiveness with established scintillators in terms of radioluminescence yield and transient behavior. Major hurdles that perovskite nanocrystal scintillators must overcome are environmental stability and toxicity. While there are still few examples of high‐performance lead‐free perovskite nanocrystal scintillators, microcrystalline perovskites are emerging with promising properties, reduced toxicity, and significant Stokes shifts to avoid reabsorption of emission in thick films. Thus, the near future of perovskite nanocrystal scintillator materials will primarily be the adoption of recipes for materials with proven properties in microcrystalline form. The nanocrystal colloidal solutions will facilitate the large‐scale printing of homogeneous and scattering‐free films to obtain high contrast and spatial resolution X‐ray images by scintillation. [ABSTRACT FROM AUTHOR]

This paper investigates the optoelectronic properties of CsPbBr3, a lead-based perovskite, and Cs2AgBiBr6, a lead-free double perovskite, in composite thick films synthesized using mechanochemical and hot press methods, with poly(butyl methacrylate) as the matrix. Comprehensive characterization was conducted, including X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV–visible spectroscopy (UV–Vis), and photoluminescence (PL). Results indicate that the polymer matrix does not significantly impact the crystalline structure of the perovskites but has a direct impact on the grain size and surface area, enhancing the interfacial charge transfer of the composites. Optical characterization indicates minimal changes in bandgap energies across all different phases, with CsPbBr3 exhibiting higher photocurrent than Cs2AgBiBr6. This is attributed to the CsPbBr3 superior charge carrier mobility. Both composites showed photoconductive behavior, with Cs2AgBiBr6 also demonstrating higher-energy (X-ray) photon detection. These findings highlight the potential of both materials for advanced photodetector applications, with Cs2AgBiBr6 offering an environmentally Pb-free alternative. [ABSTRACT FROM AUTHOR]

This study assesses the gas and water vapor permeance of PIM-derivative thin-film composite (TFC) membranes using pervaporation and "pressure increase" methods, and provides a comparative view of "time lag" measurements of thick films obtained from our previous work. In this study, TFC membranes were prepared using PIM-1 and homopolymers that were modified with different side groups to explore their effects on gas and water vapor transport. Rigid and bulky aliphatic groups were used to increase the polymer's free volume and were evaluated for their impact on both gas and water transport. Aromatic side groups were specifically employed to assess water affinity. The permeance of CO2, H2, CH4 and water vapor through these membranes was analyzed using the 'pressure increase' method to determine the modifications' influence on transport efficiency and interaction with water molecules. Over a 20 h period, the aging and the permeance of the TFC membranes were analyzed using this method. In parallel, pervaporation experiments were conducted on samples taken independently from the same membrane roll to assess water flux, with particular attention paid to the liquid form on the feed side. The significantly higher water vapor transport rates observed in pervaporation experiments compared to those using the "pressure increase" method underline the efficiency of pervaporation. This efficiency suggests that membranes designed for pervaporation can serve as effective alternatives to conventional porous membranes used in distillation applications. Additionally, incorporating "time lag" results from a pioneering study into the comparison revealed that the trends observed in "time lag" and pervaporation results exhibited similar trends, whereas "pressure increase" data showed a different development. This discrepancy is attributed to the state of the polymer, which varies significantly depending on the operating conditions. [ABSTRACT FROM AUTHOR]

It is a big challenge to prepare thick CsPbCl3 films using traditional solution processed approaches owing to the low solubility of precursors of PbCl2 and CsCl in common solvents. Here, we propose an indirect solution process to prepare thick CsPbCl3 films. In this new approach, a mother film of CsPbBr3 is first prepared through a solution process, and then it is dipped into a diluted HCl/methanol solution. During the dipping process, it triggers a halide exchange reaction between Br− and Cl−, and it eventually produces a thick CsPbCl3 film (∼400 nm) with high quality and purity. Afterwards, a carbon based hole transportation layer (HTL) free solar cell with a configuration of FTO/TiO2/CsPbCl3/carbon is constructed, and it delivers an average PCE of 1.23% and an outstanding PCE of 1.39% in a batch of PSCs. Meanwhile, the solar cell maintains its 82% initial PCE after storage in open air for 31 days. This work overcomes the obstacle of the traditional solution approach for the preparation of CsPbCl3 films, which makes it promising for preparing various CsPbCl3 film-based devices via a solution process. [ABSTRACT FROM AUTHOR]

We investigated the spin Hall effect of Pt thin films deposited by atomic layer deposition (ALD) using the MeCpPtMe3 precursor on c-plane sapphire substrates. We show that while the spin Hall conductivity of ALD-grown Pt is relatively low (0.2–0.6 × 105 ℏ 2 e Ω−1 m−1) for Pt film thicknesses less than 7 nm, it suddenly increases for thicker films, reaching 2.5–3.0 × 105 ℏ 2 e Ω−1 m−1. This behavior is attributed to the intrinsic morphology of Pt thin films grown by ALD on sapphire, where ultrathin films (<7 nm) contain small islands, while thicker films are smoother due to the coalescence of islands. Our findings underscore the necessity of growing continuous films when applying ALD-grown spin Hall materials in three-dimensional (3D) spin–orbit torque (SOT) devices. These results confirm the potential of ALD in advancing SOT applications and pave the way for the development of next-generation three-dimensional SOT spintronic devices. [ABSTRACT FROM AUTHOR]

This work proposes an original method that reveals the transformation dynamics of nanosized Bi films into semiconductor films of bismuth oxide (Bi2O3) and the factors affecting the low‐energy cold plasma on the electro‐optical properties of Bi2O3. In the plasma microreactor with a photosensitive GaAs:Cr electrode, the transformed Bi films 400–1100 nm thick are analyzed by X‐ray diffraction to determine the crystal structure of Bi2O3 and by an electron probe microanalyzer to explore the evolution of the composition. The morphological properties of the Bi films exposed to electron–ion flow are examined by processing the scanning electron microscope images. It is found that as a result of the combined effect of photoactive illumination, charged particles, and active plasma components: 1) an absorption spectrum of a new substance is formed in the range λ = 330–1100 nm; 2) the optical width of the bandgap of the resulting substance is Eg ≈ 3 eV, which satisfactorily coincides with the width of the bandgap of Bi2O3; and 3) to overcome the potential barrier and formation of semiconducting Bi2O3 film energy is required, which is provided by the combined kinetic energy of electrons and negatively charged oxygen ions bombarding on the Bi film. [ABSTRACT FROM AUTHOR]

Polaritons are generated by strong interaction between photons and matter, with the hybridization fundamentally changing the energy landscape of the system. Future exploitation of polaritons will benefit from implementing low‐cost, flexible, and easily tuneable configurations, as electronics have before. Here, coherent coupling of the carbonyl stretch vibrations of polyester (poly(ethylene terephthalate), PET) films to the optical modes of a Fabry–Perot (FP) cavity is presented, in which the FP cavity is directly formed on flexible, free‐standing, and commercially available PET films. For 2‐µm thick PET films, the carbonyl stretch vibration of the PET overlaps with the half‐wavelength FP cavity mode, leading to the coupling of the two modes, a Rabi splitting above 160 cm−1, and associated anticrossing in angular dispersion measurements. The study demonstrates dynamic control of light‐matter interaction strength by modulating film thickness under tension, finding that a 25% tensile stretch can tune the light‐matter interaction from 20:80 mixing to near‐perfect 50:50 hybridization at normal incidence. These findings are discussed in the context of future foldable/twistable/wearable polaritonic devices. [ABSTRACT FROM AUTHOR]

In the present paper, we studied the microstructural and sensing behaviors of undoped SnO2 and PbO-doped SnO2 thick film. Three samples have been fabricated using the screen-printing technique on an aluminum substrate and these are S1 (undoped SnO2) S2 (1wt% PbO doped SnO2 firing at 800 oC), and S3 (1 wt% PbO doped SnO2 firing at 900 oC). XRD and AFM techniques are used to observe the microstructural behaviors and it is found that the crystallite size decreases with PbO doping. The reduction in crystallinity is to improve the sensing application. The sensing properties such as sensing response, selectivity, and transient time of the deposited thick films were studied at an operating temperature of 200 oC for various test gases such as ethanol, LPG, and acetone concentrations (0–5000 ppm level). Also, we found that the response of sensor S3 to the ethanol gas is ~ 3.38 times of LPG and ~ 1.95 times that of acetone gas. The response and recovery times of the ethanol gas for the S3 sensor are 41s and 125s, respectively. Therefore, the PbO doping improves the response and recovery time for ethanol gas (5000 ppm) over LPG and acetone. [ABSTRACT FROM AUTHOR]

Elemental tellurium electrical switch, relying on a transient crystal–liquid–crystal phase transition, has recently been proposed as a promising selector candidate for the next‐generation 3D high‐density memory, bridging performance gap in today's computer. Further miniaturization of the switch cell to increase memory density strongly depends on the scalability of the tellurium film, which, however, has not been experimentally studied. Herein, the tellurium films are prepared with the thickness downscaled from 400 to 2 nm and a significant increase is found in the bandgap from 0.29 to 0.91 eV, as predicted by ab initio molecular dynamics. Interestingly, the as‐deposited tellurium films with a thickness above 3 nm are in the crystalline trigonal phase, whereas 2 nm thick film suddenly becomes amorphous, observed by both Raman and transmission electron microscopies. In this finding, since the leakage current of the elemental tellurium switch is determined by both the Schottky barrier between tellurium/electrode interface and the bandgap of the tellurium film, a reduction in leakage current is predicted with further miniaturization. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) are a promising alternative to traditional silicon-based photovoltaic systems due to their efficient light-to-electricity conversion. A critical component of DSSCs is titanium dioxide (TiO2), responsible for converting light into electrical energy. Spray pyrolysis was one of the methods for fabricating TiO2 thin films. However, there are several drawbacks, such as challenges in particle size control, maintaining homogeneity of the thin film, and scalability issues during the deposition process. Modifications to the manufacturing process are necessary to achieve optimal performance in DSSCs, particularly with the thickness of the cell. This work focuses on the 2-axis spray pyrolysis process, a cost-effective way to create thin and thick films. In particular, it focuses on TiO2 thin films utilized as working electrodes in DSSC applications. The method was performed at different motor speeds, namely MS80, MS100, and MS120. The X-ray diffraction (XRD) spectrum showed that the dominance of the anatase phase appeared in an MS100. The UV-Vis results depict that the band gap value is 3.02 eV. The surface profiler analysis indicates that sample MS100 has an optimal thickness of 15.17 µm. The DSSC achieved 9.4% efficiency with sample MS100. This finding demonstrates that using 2-axis controlled spray pyrolysis deposition improves DSSC performance with an optimal motor speed. [ABSTRACT FROM AUTHOR]