Search

This study is the first attempt to examine the electrochemical properties of TiO 2 composite with Fe 3 O 4 thin film. In our analysis, X-Ray diffraction (XRD) confirms the formation of Fe 3 O 4 on TiO 2. Fourier Transform Infrared Spectroscopy (FT-IR) and Raman spectroscopy confirmed the functional groups. The UV–Vis spectroscopy analysis shows that the addition of Fe 3 O 4 results in decrease in optical band gap. Our Cyclic Voltammetry (CV) results demonstrate that, under steady state conditions, the behaviors of TiO 2 and Fe 3 O 4 /TiO 2 electrodes regarding ion adsorption and charge transmission vary. Pseudocapacitive effects and charge transfer affects the functionality of the TiO 2 electrode, whereas two-layer capacitance effects primarily control the response of the Fe 3 O 4 /TiO 2 electrode. Numerous factors, including ion diffusion, rate capability, charge transfer, and series resistance, can be directly determined using electrochemical impedance spectroscopy (EIS). The experimental results and analysis presented in this work brings to light the significance of Fe 3 O 4 in the electrochemical response of an electrode-electrolyte interface. [ABSTRACT FROM AUTHOR]

In this work, the transverse size effect of the new-generation relaxor ferroelectric Pb(In 1/2 Nb 1/2)O 3 -Pb(Mg 1/3 Nb 2/3)O 3 -PbTiO 3 (PIMNT) thin film was studied by finite element method, aiming to revealing the lateral size and shape dependence of the piezoelectric, dielectric, and pyroelectric behavior for guiding one- and two-dimensional integrated array sensor applications. The results indicated that as the aspect ratio (width to thickness ratio) decreased from 100 to 0.01, for both one-dimensional rectangular and two-dimensional square PIMNT array elements, a sharp increase in piezoelectric and dielectric constants could be observed for the PIMNT with <001> direction while a slight increase could be found for those along <111> orientation, exhibiting a strong orientation dependence. In comparison, the PIMNT with <110> direction exhibited strong shape dependence. The piezoelectric and dielectric constants of <110>-oriented square element increased more remarkably than those of the rectangular one. The pyroelectric coefficients of PIMNT exhibited weak shape dependence, decreasing from 8.5 × 10−4 C/(m2·K) to about 8.0 × 10−4 C/(m2·K) for both element shapes with transverse size decreasing. These findings give insight into the transverse size and shape effect on the new-generation PIMNT thin film and provide a guide for its design in one- and two-dimensional piezoelectric and pyroelectric array sensor applications. [ABSTRACT FROM AUTHOR]

A linear sixth-order partial differential equation (PDE) of "parabolic" type describes the dynamics of thin liquid films beneath surfaces with elastic bending resistance when deflections from the equilibrium film height are small. On a finite domain, the associated sixth-order eigenvalue problem is self-adjoint for the boundary conditions corresponding to a thin film in a closed trough, and the eigenfunctions form a complete orthonormal set. Using these eigenfunctions, we derive the Green's function for the governing sixth-order PDE on a finite interval and compare it to the known infinite-line solution. Further, we propose a Galerkin spectral method based on the constructed sixth-order eigenfunctions and their derivative expansions. The system of ordinary differential equations for the time-dependent expansion coefficients is solved by standard numerical methods. The numerical approach is applied to versions of the governing PDE with a second-order spatial derivative (in addition to the sixth-order one), which arises from gravity acting on the film. In the absence of gravity, we demonstrate the self-similar intermediate asymptotics of initially localized disturbances on the film surface, at least until the disturbances "feel" the finite boundaries, and show that the derived Green's function is an attractor for such solutions. In the presence of gravity, we use the proposed Galerkin numerical method to demonstrate that self-similar behavior persists, albeit for shortened intervals of time, even for large values of the gravity-to-bending ratio. [ABSTRACT FROM AUTHOR]

The molecular self‐organization and reorganization and thus volumetric and density changes during structural relaxation and melting of modern organic semi‐conducting materials remains largely unknown, particularly in the device relevant thin film geometry where the initial state may be structurally quenched away from equilibrium. Here, the apparent mass‐thickness of a range of semi‐conducting polymeric or molecular model materials systems is measured through in situ ellipsometry. Surprisingly, the volume changes upon melting correlate inversely, with a few exceptions, to the quality of crystallinity found via x‐ray methods (i.e., directly correlate with the paracrystalline g‐parameter) rather than the melting enthalpy that is possibly a proxy for the degree of crystallinity. This study also observes changes in orientation and/or density due to segmental relaxation during the first heat, thus complementing other characterization methods that measure relaxation or reorganization transitions. Semiconducting materials exhibit very large melt expansion and a richer phase‐behavior compared to commodity polymers, presumably due to their complex chemical structure. The results delineate an important and novel structure‐function relation that, together with simulations constrained by these results, will lead to better rational design of semi‐conducting materials. [ABSTRACT FROM AUTHOR]

Efficient wound and burn healing is crucial for minimising complications, preventing infections, and enhancing overall well-being, necessitating the development of innovative strategies. This study aimed to formulate a novel thin film combining chitosan, carboxymethyl cellulose, tannic acid, and beeswax for improved wound healing applications. Several formulations, incorporating chitosan, carboxymethyl cellulose, tannic acid, and beeswax in various percentages, were utilized to deposit thin films via the solvent evaporation technique, Mechanical properties, morphology, antioxidant activity, antibacterial efficacy, and wound healing potential were evaluated. The optimized thin film (M4), composed of 2% chitosan, 2% carboxymethyl cellulose, and 1% tannic acid, along with 0.2% glycerol and 0.2% tween80, exhibited a thickness of 39.0 ± 1.14 μm and a tensile strength of 0.275 ± 0.003 MPa. It demonstrated a swelling degree of 283.0 ± 2.0% and a drug release capacity of 89.4% within 24 h. The film also showed a low contact angle of 40.5° and a water vapour transmission rate of 1912.25 ± 13.10 g m−2 0.24 h−1. FT-IR spectroscopy indicated that chitosan and carboxymethyl cellulose were cross-linked through amide linkages, with tannic acid occupying the interstitial spaces and hydrogen bonding stabilizing the structure. Microscopy of M4 revealed a uniform morphology. The film exhibited strong antioxidant activity of (95.17 ± 0.02%) and antibacterial efficiency (80.8%) against S. aureus. In a rabbit model, the film significantly enhanced burn and excision wound recovery, with 90.0 ± 3.3% healing for burns and 88.85 ± 1.7% for infected wounds by day 7. Complete skin regeneration was observed within 10–12 days. The M4 thin film demonstrated exceptional mechanical properties and bioactivity, offering protection against pathogens and promoting efficient wound healing. These findings suggest its potential for further investigation in treating various infections and its role in developing novel therapeutic interventions. [ABSTRACT FROM AUTHOR]

Thin composite films hold great promise for microwave devices for microwave absorption. This work mainly focuses on the investigation of the microwave absorption and mechanical studies of a composite thin film of activated carbon and manganese ferrite as conductive fillers within a polyvinylidene fluoride (PVDF) matrix. The production of activated carbon was successfully accomplished using a pyrolysis technique. Composite films consisting of polyvinylidene fluoride (PVDF) and activated carbon‐manganese ferrite were fabricated using a solution blending method. The composite films maintained a consistent concentration of activated carbon at 5 wt%. The characterization of the materials was conducted using scanning electron microscopy and X‐ray diffraction. The composite consists of 3 wt% of MnFe2O4 and 5 wt% Activated carbon/PVDF showed exceptional absorption properties and achieved a minimum reflection loss of around −38 dB at a frequency of 8–12 GHz at a thickness of 2 mm. Significantly, the composite film exhibited a greater tensile strength than the PVDF film. The results of our study highlighted the enhanced microwave absorption and economical manufacturing technique for producing composite films. These films exhibit promising microwave‐absorbing properties in stealth applications. Highlights: A facile strategy to fabricate thin film PVDF composites was proposed.Novel activated carbon was synthesized to enhance the conductivity.Achieved reflection loss of around −38 dB at a frequency of 8–12 GHz.Synergistic effects of fillers enhanced dielectric and magnetic losses.Exhibited efficient mechanical performance and microwave absorption. [ABSTRACT FROM AUTHOR]

Cadmium Selenide CdSe thin films were deposited on (7.5x1.3x0.1 cm³) glass substrates and (1x1 cm²) p-type silicon substrates using pulsed laser deposition technique (Nd: YAG laser beam with 80 mJ energy, λ = 1064 nm). Then, they were annealed at 300 °C for 1 h to get diodes as visible light detectors. Some of these samples (diodes) were exposed to different intervals (5, 7, 9, 12) days of neutron radiation using (241Am-10Be) source with a flux of 3x105 n/cm².s and energy of 5.71 MeV. For comparison purposes, the other diodes were kept without any irradiation The morphological and electrical properties of these samples were studied by XRD, FE-SEM and I-V measurements. Results have shown all these thin films exhibit a hexagonal structure. However, there is a slight shift in the preferred orientation (100) for the irradiated films. Also, there was a new (102 - SiO2) peak that appeared in the irradiated thin film pattern. The crystallite size of pristine and (5, 7, 9, 12) days irradiated CdSe thin films were (26.9, 18.3, 24.9, 20.3 and 24.5) nm respectively, whereas, the mean particle size of the pristine film was 37 nm whereas for the irradiated films 53, 64, 73 and 92 nm. Results also show that the band gap of these samples increased from 2.17 eV for pristine thin films to 2.3, 2.48, 2.25, and 2.3 eV for the irradiated thin films. On the other hand, the results of I-V characteristics show the dark/light current. The current under illumination increases when exposed to small values of neutron radiation then it decreases with higher values of exposure. In contrast, the dark current decreases significantly with the irradiation. The effect of the irradiation was clear on the response/recovery period for all devices. Nevertheless, it was more profound in the response/recovery time of pristine devices. Also, the photo-responsivity of the pristine device was larger than the other devices and it was decreased with increasing absorbed doses. [ABSTRACT FROM AUTHOR]

In recent years, the efficiency of high-efficiency Cu(In,Ga)Se2 (CIGS) solar cells has been significantly improved, particularly for narrow-gap types. One of the key reasons for the enhancement of narrow-gap device performance is the formation of the "Spike" structure at the CdS/CIGS heterojunction interface. Wide-gap CIGS solar cells excel in modular production but lag behind in efficiency compared to narrow-gap cells. Some studies suggest that the "Cliff" structure at the heterojunction of wide-gap CIGS solar cells may be one of the factors contributing to this decreased efficiency. This paper utilizes the SCAPS software, grounded in the theories of semiconductor physics and photovoltaic effects, to conduct an in-depth analysis of the impact of "Cliff" and "Spike" heterojunction structures on the performance of wide band gap CIGS solar cells through numerical simulation methods. The aim is to verify whether the "Spike" structure is also advantageous for enhancing wide-gap CIGS device performance. The simulation results show that the "Spike" structure is beneficial for reducing interfacial recombination, thereby enhancing the VOC of wide-gap cells. However, an electronic transport barrier may form at the heterojunction interface, resulting in a decrease in JSC and FF, which subsequently reduces device efficiency. The optimal heterojunction structure should exhibit a reduced "Cliff" degree, which can facilitate the reduction of interfacial recombination while simultaneously preventing the formation of an electronic barrier, ultimately enhancing both VOC and device performance. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) with redox-active metal ions and a variety of organic linkers have been widely investigated as prospective electrode materials for supercapacitors. Here, we generate uniformly dense spherical particles on a nickel foam substrate by a simple and binder-free one-step electrodeposition method by adjusting the deposition conditions. The active cobalt in the Co-MOF thin films can provide a large number of redox sites for the electrochemical reaction, while the uniform binder-free Co-MOF structure can keep enough contact area with the electrolyte to reduce the ion transport resistance. As-prepared CTB-0.9 (Co-MOF with a deposition voltage of − 0.9 V) thin film has a specific capacitance of 797.5 F g−1 at a current density of 1 A g−1, exhibiting excellent electrochemical properties. An asymmetric supercapacitor with CTB-0.9 as the positive material and activated carbon as the negative material also demonstrates competitive electrochemical performances, which has a high energy density of 34.3 Wh Kg−1 at a power density of 36,317.6 W Kg−1. This work may open up an effective approach to realize the electrosynthesis of Co-MOF films, promoting the utilization of Co-based MOFs in energy storage and conversion fields. [ABSTRACT FROM AUTHOR]

The investigation of heat transmission and entropy optimization in the thin-film flow of electromagnetic micropolar nanofluids has important implications in industrial lubrications, surgical instruments, and improved cooling systems. The Maxwell–Bruggeman and Krieger–Dougherty models are employed in this study to provide the nanoparticle aggregation/without aggregation attributes affecting the fluid characteristics. The Krieger-Dougherty model examines the modified viscosity caused by concentration of nanoparticle and accumulation, whereas the Maxwell-Bruggeman model assesses the effective thermal conductivity. The flow of micropolar nanofluid is assumed unsteady and laminar. The fundamental equations that govern the flow model are coupled into differential equations by applying appropriate similarity variables. The modeled problem have been solved through the implementation of the Runge–Kutta numerical technique. The findings elucidate that the micropolar effects such as Eringen parameter, spin gradient viscosity, and microrotation have a significant impact on the thin film thermodynamic behavior and flow kinetics. The electromagnetic fields alters the flow and thermal behavior significantly. It has been established that uniform dispersion of nanoparticles is crucial for optimizing thermal efficiency and reducing problems associated with aggregation and without aggregation. It is observed that when agglomeration is considered, the skin friction, entropy and Nusselt number increases significantly. [ABSTRACT FROM AUTHOR]

For catalyzing the oxygen evolution reaction, earth‐abundant materials with high activity and stability need to be developed. NiCo2O4 has been proven to show high OER activity, however facile and inexpensive techniques for preparation of this compound as mesostructured thin film, possessing a high surface area, is lacking. In this study, the sol‐gel synthesis of nanocrystalline, mesoporous spinel NiCo2O4 thin films by dip‐coating and soft‐templating using the evaporation‐induced self‐assembly approach and utilizing the tri‐block‐copolymer Pluronic® F‐127 as structure‐directing agent is reported. The morphology and crystallographic structure were thoroughly probed by various physicochemical characterization techniques collectively validating the development of uniform mesoporous NiCo2O4 architectures crystallizing exclusively in the cubic spinel phase after calcination in air at ether 300 °C, 400 °C, or 500 °C. The surface area of thin films increased from 300 °C to 400 °C owing to degradation of the organic template, while the growth of the mesopores from 400 °C to 500 °C resulted in significant decline of the overall (electrochemical) surface area. XPS investigations showed that the amount of octahedrally coordinated Ni3+ and defective (low‐coordinated) oxygen species increased for decreasing calcination temperatures. The nanomorphology and presence of catalytically active surface sites of the mesoporous NiCo2O4 electrodes were correlated with the electrochemical properties, presenting that the overall surface area, Ni3+ content, charge transfer resistance, and amount of defective oxygen sites collectively control the OER performance. After an optimized annealing procedure at 300 °C and chronopotentiometric analysis at 10 mA/cm2 for 1.5 h, a low overpotential of 330 mV vs. RHE at 10 mA/cm2 in alkaline solution was achieved. The results highlight the necessity of precise selection of the appropriate calcination temperature and tailoring of the nanostructure and electrochemical pre‐treatment conditions of NiCo2O4 sol‐gel thin films for adjusting the concentration of electrocatalytically active reaction sites. [ABSTRACT FROM AUTHOR]

Biaxial stress is identified to play an important role in the polar orthorhombic phase stability in hafnium oxide‐based ferroelectric thin films. However, the stress state during various stages of wake‐up has not yet been quantified. In this work, the stress evolution with field cycling in hafnium zirconium oxide capacitors is evaluated. The remanent polarization of a 20 nm thick hafnium zirconium oxide thin film increases from 9.80 to 15.0 µC cm−2 following 106 field cycles. This increase in remanent polarization is accompanied by a decrease in relative permittivity that indicates that a phase transformation has occurred. The presence of a phase transformation is supported by nano‐Fourier transform infrared spectroscopy measurements and scanning transmission electron microscopy that show an increase in ferroelectric phase content following wake‐up. The stress of individual devices field cycled between pristine and 106 cycles is quantified using the sin2(ψ) technique, and the biaxial stress is observed to decrease from 4.3 ± 0.2 to 3.2 ± 0.3 GPa. The decrease in stress is attributed, in part, to a phase transformation from the antipolar Pbca phase to the ferroelectric Pca21 phase. This work provides new insight into the mechanisms controlling and/or accompanying polarization wake‐up in hafnium oxide‐based ferroelectrics. [ABSTRACT FROM AUTHOR]

The field of flexible electronics has experienced remarkable expansion in response to the escalating demand for lightweight, bendable, and multifunctional electronic devices. As the world increasingly integrates electronics seamlessly into everyday life, the importance of flexible electronics becomes more apparent. While existing reviews have examined materials used in flexible devices, they often overly focus on specific materials or provide broad generalizations about different material types. Thus, this review offers a concise yet comprehensive overview of critical inorganic film materials crucial to the advancement of flexible and wearable devices. Each material is introduced with a succinct overview of its structure and production processes. This review elucidates their unique characteristics and potential applications in flexible electronics by comparing their mechanical, electrical, and thermal properties. This review is a valuable resource for researchers entering this emerging field of flexible electronics, providing a concise yet comprehensive insight and property comparisons. Accompanied by figures illustrating material structures and applications, readers will gain access to summarized discussions. Comparative figures of material properties will enhance comprehension. Additionally, discussions on diverse applications will offer insight into their versatility across various fields of flexible electronics. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide (rGO)-embedded WO3 composite thin film (rGO-WO3) is synthesized and investigated for its electrochromic performances. Furthermore, a novel application of quantum dot-sensitized solar cells (QDSSCs), to operate the rGO-WO3 electrochromic devices (ECDs), is demonstrated with development of an integrated device. The co-existence of both WO3 nanostructure and rGO sheet ameliorates the EC performances of composite thin film, compared to WO3 thin film. The rGO-WO3, possessing 0.1 g of rGO, nanocomposite shows an optimum optical contrast (%ΔT) of 66.3% and excellent optical stability displaying 1.7% degradation in %ΔT, while the WO3 film only exhibits a %ΔT of 52.2% and, 4.2% of optical degradation. Incorporation of rGO sheet into the WO3 nanostructure introduces de-agglomerated morphology, enhances electrochemically active surface area, and which facilitates the ion-transfer kinetics. The series-connected QDSSCs results an optimum open circuit voltage (Voc) of 1.03 V upon 1 sun illumination, which is found to be adequate for the study of switching performances of ECDs. QDSSCs assisted rGO-WO3 EC film exhibits a significant %ΔT of 43% and coloration time of 7 s. Additionally, QDSSCs device is illuminated with various light intensities to study the intensity and Voc dependent EC performances of rGO-WO3. [ABSTRACT FROM AUTHOR]

Thin film technology is significant in technological progress and modern research because it allows for the production of optoelectronic devices with improved characteristics. Because of its superior chromatic efficiency, tungsten oxide (WO3) is one of the best candidates for energy-saving applications. In this study, undoped and tin (Sn)-doped WO3 films were grown on top of WO3 seed layers directly by a facile hydrothermal route at a temperature as low as 110∘C for 24 h. The seed layers were also deposited on top of glass substrates using spray pyrolysis. The results of tin doping on the structural, optical, and morphological characteristics of the WO3:Sn films were studied. X-ray diffraction patterns show that peak intensities increase significantly by adding Sn and the films' crystallinity was improved by rising Sn content. In the visible region, the average optical transmittance is around 13% and the optical bandgap changes from 2.61 eV to 2.81 eV, by increasing the dopant amount. Finally, the room temperature photoluminescence of samples shows intense green light emissions. The results of this research can be beneficial for the fabrication and performance optimization of electrical and optical devices such as gas sensors, electrochromic devices, and photosensors. [ABSTRACT FROM AUTHOR]

With the advent of the internet era, wearable electronic devices and flexible electronic technology are rapidly emerging, and new resistive random access memory (RRAM) based on flexible substrates have thus gained extensive attention. Here, the flexible Bi 0·95 Er 0·05 FeO 3 /ZnO/La 0·66 Sr 0·34 MnO 3 (BEFO/ZnO/LSMO) heterostructure is prepared on Mica substrate using the sol-gel method. The high resistance state (HRS) to low resistance state (LRS) ratio consistently surpasses 102 under the flat and the 15 mm bending radius state. There is no significant change in the resistive switching (RS) behavior after 30 I–V curve cycles and 103 write/erase operations on the BEFO/ZnO/LSMO heterostructure, which reflects excellent stability. In addition, the device still works properly at 175 °C for dynamic conversion between HRS and LRS. The observed RS behavior in the BEFO/ZnO/LSMO heterostructure is attributed to ion migration and alterations in the potential barrier height at the interfaces. These results suggest that the BEFO/ZnO/LSMO heterostructure based on a flexible Mica substrate plays a crucial role in the development of next-generation portable and flexible electronic systems due to its excellent flexibility and thermal stability. [ABSTRACT FROM AUTHOR]

Polymers have distinctive optical properties and facile fabrication methods that have been well-established. Therefore, they have immense potential for nanophotonic devices. Here, we demonstrate the temperature-sensing potential of SU8-meta-phenylenediamine (SU8-mPD), produced by epoxy amination of the SU-8 polymer. Its properties were examined through a series of molecular structural techniques and optical methods. Thin layers have demonstrated optical emission and absorption in the visible range around 420 and 520 nm, respectively, alongside a strong thermal responsivity, characterized by the 18 ppm °C−1 expansion coefficient. A photonic chip, comprising a thin 5–10 μm SU8-mPD layer, encased between parallel silver and/or gold thin film mirrors, has been fabricated. When pumped by an external light source, this assembly generates a pronounced fluorescent signal that is superimposed with the Fabry–Pérot (FP) resonant response. The chip undergoes mechanical deformation in response to temperature changes, thereby shifting the FP resonance and encoding temperature information into the fluorescence output spectrum. The time response of the device was estimated to be below 1 s for heating and a few seconds for cooling, opening a new avenue for optical sensing using SU8-based polymers. Thermoresponsive resonant structures, encompassing strong tunable fluorescent properties, can further enrich the functionalities of nanophotonic polymer-based platforms. This article is part of the theme issue 'Celebrating the 15th anniversary of the Royal Society Newton International Fellowship'. [ABSTRACT FROM AUTHOR]

We report the pulsed laser deposition (PLD) of nanocrystalline/amorphous homo-composite BaTiO3 (BTO) films exhibiting an unprecedented combination of a colossal dielectric constant (εr) and extremely low dielectric loss (tan δ). By varying the substrate deposition temperature (Td) over a wide range (300–800 °C), we identified Td = 550 °C as the optimal temperature for growing BTO films with an εr as high as ~3060 and a tan δ as low as 0.04 (at 20 kHz). High-resolution transmission electron microscopy revealed that the PLD-BTO films consist of BTO nanocrystals (~20–30 nm size) embedded within an otherwise amorphous BTO matrix. The impressive dielectric behavior is attributed to the combination of highly crystallized small BTO nanograins, which amplify interfacial polarization, and the surrounding amorphous matrix, which effectively isolates the nanograins from charge carrier transport. Our findings could facilitate the development of next-generation integrated dielectric devices. [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]

The structure of metal oxide thin films can greatly affect their gas sensing properties. However, the structure-property relationship has not been fully established for the NO 2 sensing properties of WO 3 thin films. In this study, WO 3 thin films with two distinct structures have been prepared by the sol-gel technique via employing two different precursor sols. Dense and porous WO 3 thin films were successfully prepared as tungsten and WCl 6 was used as the precursor source, respectively. Both WO 3 thin films are exclusively sensitive to NO 2 as low as 80 ppb. Porous WO 3 thin films exhibit higher response toward NO 2 but slower response/recovery kinetics as compared to the dense ones. Hall measurement and electrochromic coloration confirm the higher carrier mobility in the porous WO 3 thin films. The response/recovery kinetics is found to be determined by the gas-solid reaction (receptor function), which is combinedly influenced by the porosity and grain size of the WO 3 thin films. [ABSTRACT FROM AUTHOR]

In today's modern world, energy consumption continues to escalate. In such cases, smart windows play a crucial role in reducing energy consumption and enhancing the quality of life. Electrochromic devices (ECDs) -based smart windows rely profoundly on nickel oxide (NiO) thin films, which act as a counter electrode in ECDs. This work aims to fabricate NiO thin films, with the intention of achieving ultrafast ECD. Through the sputtering technique, energy-efficient ECD is obtained with the highest optical modulation of 60 % at a rapid switching speed of 0.55s for bleaching and 0.95s for coloration. We have also investigated the structural, morphological, vibrational, and optical properties of NiO thin films. XRD analysis revealed the less crystalline or near amorphous nature of NiO thin film. XPS, PL, and Raman studies confirm the existence of defects in the film. The favourable, less crystalline nature, along with the presence of defects, facilitates ultra-fast ion intercalation and de-intercalation process. We believe that prepared NiO film can be used as a promising anodic colourant in electrochromic smart windows with applications in energy-efficient buildings. [ABSTRACT FROM AUTHOR]

The structure and properties of polycrystalline chemical vapor deposition (CVD) diamond coatings grown by microwave plasma CVD in H2–CH4 mixtures can be effectively controlled by nitrogen admixture in the process gas. Here, a comparative study of adding nitrogen from different precursors, N2 and ammonia NH3, in concentrations up to 0.4%vol on grain size, texture, surface roughness, and sp2/sp3 ratio of the produced films on Si substrates is performed. A transition from microcrystalline to smooth nanocrystalline diamond structure is found to occur at a certain concentration of the precursor, for NH3 this threshold concentration being much lower, 0.02–0.1%, than for N2. The higher activity of ammonia is associated with easier formation of cyano radicals in the plasma as detected with optical emission spectroscopy, in accord with the lower bond‐dissociation energy for NH3 compared to N2. On the contrary, a smaller addition (0.004%) of either N2 or NH3 promotes almost doubling of the growth rate, while preserving the microcrystalline structure of the film. The results establish ammonia as a convenient alternative precursor to commonly used N2 added in the plasma for the diamond film structure modifications. [ABSTRACT FROM AUTHOR]

The nanostructured assembly of different two‐dimensional (2D) materials in specific organization is crucial for developing materials with synergistic properties. In this study, we present a general methodology to prepare thin, transparent and self‐assembled films of 2D/2D composites based on molybdenum sulfide (MoS2)/graphene oxide (GO) or MoS2/reduced graphene oxide (rGO), through the liquid/liquid interfacial route. Different nanoarchitectures are obtained by changing simple experimental parameters during the thin film preparation steps. The films were characterized by UV‐Vis and Raman spectroscopy, scanning electron microscopy and cyclic voltammetry, evidencing that the experimental route used plays a role in the organization and properties of the assembled nanoarchitectures. Likewise, nanostructures of MoS2/GO and MoS2/rGO prepared through the same route have different organizations due to the different interactions between the materials. This showcases the potential of the technique to prepare tailored nanoarchitectures with specific properties for various applications, paving the way for innovative nanotechnology and materials science applications. [ABSTRACT FROM AUTHOR]

This work discusses label-free biosensing application of a double-layer optical fiber interferometer where the second layer tailors the reflection conditions at the external plain and supports changes in reflected optical spectrum when a bio-layer binds to it. The double-layer nanostructure consists of precisely tailored thin films, i.e., titanium (TiO2) and hafnium oxides (HfO2) deposited on single-mode fiber end-face by magnetron sputtering. It has been shown numerically and experimentally that the approach besides well spectrally defined interference pattern distinguishes refractive index (RI) changes taking place in a volume and on the sensor surface. These are of interest when label-free biosensing applications are considered. The case of myeloperoxidase (MPO) detection—a protein, which concentration rises during inflammation—is reported as an example of application. The response of the sensor to MPO in a concentration range of 1 × 10−11–5 × 10−6 g/mL was tested. An increase in the MPO concentration was followed by a redshift of the interference pattern and a decrease in reflected power. The negative control performed using ferritin proved specificity of the sensor. The results reported in this work indicate capability of the approach for diagnostic label-free biosensing, possibly also at in vivo conditions. [ABSTRACT FROM AUTHOR]

Fabrication and characterization of solar cells based on multicrystalline silicon (mc‐Si) thin films are described and synthesized from low‐cost soda‐lime glass (SLG). The aluminothermic redox reaction of the silicon oxide in SLG during low‐temperature annealing at 600 – 650 °C leads to an mc‐Si thin film with large grains of lateral dimensions in the millimeter range, and moderate p‐type conductivity with an average Al acceptor concentration between 5 × 1016 and 1.2 × 1017 cm−3 in the bulk. A residual composite layer of mainly alumina and unreacted Al forms beneath the mc‐Si thin film as the second product of the crystalline silicon synthesis (CSS) process, which can be used as rear contact in a vertical solar cell design. The mc‐Si absorber (≈10 µm) is thin enough that the diffusion length given by a minority carrier lifetime of ≈1 µs exceeds the path length to the top contact several times. Homojunction and heterojunction diodes have been fabricated on the mc‐Si thin films and show great potential of CSS for the realization of high‐performance solar cells. [ABSTRACT FROM AUTHOR]

Zinc sulfide thin films were prepared using the economical spray pyrolysis process. A thin film of exceptional quality with a temperature difference of 300 °C to 400 °C is produced by optimizing variables such as concentration, flow rate, and nozzle to substrate distance. These films' optical characteristics and structure were examined. The deposited thin films displayed a direct and allowed transition, as indicated by the optical transmittance spectra. XRD analysis confirmed that the deposited thin films were polycrystalline with a cubic phase. This film can be used in solar cell applications since the band gap energy fluctuation is high enough, ranging from 3.42 to 3.81 eV. [ABSTRACT FROM AUTHOR]

Superconducting nanowire single-photon detectors are widely used in various fields of physics and technology, due to their high efficiency and timing precision. Although, in principle, their detection mechanism offers broadband operation, their wavelength range has to be optimized by the optical cavity parameters for a specific task. We present a study of the optical absorption of a superconducting nanowire single photon detector with an optical cavity. The optical properties of the niobium nitride films, measured by spectroscopic ellipsometry, were modeled using the Drude–Lorentz model with quantum corrections. The numerical simulations of the optical response of the detectors show that the wavelength range of the detector is not solely determined by its geometry, but the optical conductivity of the disordered thin metallic films contributes considerably. This contribution can be conveniently expressed by the ratio of imaginary and real parts of the optical conductivity. This knowledge can be utilized in detector design. [ABSTRACT FROM AUTHOR]

Thin films of BiOCl, BiOBr, and BiOI (BiOX) were deposited by thermal evaporation for their potential application in the decontamination of water and air through their photocatalytic activity, which was compared among the three. The BiOX thin films were subjected to characterization through X-ray diffraction, high-resolution transmission electron microscopy, and scanning electron microscopy. Additionally, the optical properties were determined from the diffuse reflectance spectrum obtained with a spectrophotometer. To assess the efficacy of the semiconductor films in water decontamination, the evolution of rhodamine B discoloration and its mineralization was monitored by measuring total organic carbon. The decontaminating activity in the air was evaluated in a gas reactor, measuring the conversion of NOx-type gases. The results demonstrated that the thin films of the three oxides exhibited decontaminating photocatalytic activity in both water and air. However, notable distinctions were observed in the photocatalytic activities of the three bismuth oxyhalides in water, while in air, they exhibited similarities. In aqueous environments, the mineralization percentages exhibited notable variation after 96 h, with the BiOBr film displaying a value of 9.2%/mg and the BiOCl film a value of 3.9%/mg. In contrast, the NO conversion rate in the air was approximately 0.6%/mg for the three oxyhalide films. [ABSTRACT FROM AUTHOR]

In current years, the growth of high-k dielectric thin films with reduced charge density and leakage current has drawn tremendous attention for microelectronic devices. Ta2O5 thin film is deposited on p-type silicon substrate using radio frequency sputtering deposition technique for high-k dielectric applications. The as-deposited films undergo post-deposition annealing treatment at temperatures ranging from 600 °C to 900 °C for 1 h in air ambient. X-ray diffraction analysis revealed the formation of a polycrystalline orthorhombic β – Ta2O5 structure in the annealed films. The RMS roughness of the film is found to be increased from 2.3 nm to 3.7 nm with the increase in annealing temperature to 900 °C. Metal–oxide–semiconductor (Al/Ta2O5/p-Si) structures are fabricated using thermal evaporation for electrical characterizations. The capacitance-voltage (at 1 MHz) of this structure is measured for the sweep voltage from − 4 V to + 4 V. The oxide charge density and interface charge density of the film have been calculated from the C-V curve and found to decrease with the increase in annealing temperature. The highest dielectric constant value of 24.5 at 1 MHz is found for film annealed at 800 °C. The leakage current is measured from the current-voltage measurement and found to be minimum for the film annealed at 800 °C. [ABSTRACT FROM AUTHOR]

Using the radio frequency magnetron sputtering process, NaNbO3-based antiferroelectric thin films were obtained on Pt(111)/Ti/SiO2/Si substrates. The effects of annealing temperature on the phase structure, dielectric properties, ferroelectric properties, and energy storage properties of the thin films were studied. As the annealing temperature increased, the crystallinity and film quality of the thin films improved. Moreover, oxygen vacancies were effectively suppressed, which is beneficial for the thin film to obtain a higher dielectric constant, a larger saturation polarization, and a smaller residual polarization intensity. The NaNbO3-based thin film has a higher energy storage density, power density and efficiency (Wrec = 3.6 J/cm3, Pd =200.8 kW/cm3, η = 68.31%) at an annealing temperature of 600 ℃. The observed phenomenon could be attributed to higher breakdown field strength and polarization difference resulting from the appropriate annealing temperature and the presence of lower oxygen vacancies under pure oxygen atmosphere. The wonderful property of the NaNbO3-based thin film indicates that it will have the potential to be applied in a wide range of contexts within the sphere of energy storage. [ABSTRACT FROM AUTHOR]

The surface quality of the substrate has an important effect on the quality of the growth film. The roughness, uniformity, adhesion residue and oxide layer of the substrate are the evaluation criteria of its surface performance. In this paper, an in-situ thermal treatment method to remove the natural oxides on GaSb (001) substrates for epitaxial growth of CdZnTe films by close-spaced sublimation method was reported. By controlling the temperature and time of the thermal treatment, a clean and smooth substrate state is obtained. The effect of thermal treatment on the morphology and composition of GaSb substrate was analyzed by atomic force microscopy and X-ray photoelectron spectroscopy. The crystal quality of CdZnTe epitaxial film grown on GaSb substrate after thermal treatment was evaluated by double crystal X-ray curve. In order to further study the properties and epitaxial formation mechanism of the micro-defects near the heterogeneous interface, TEM analysis of CdZnTe/GaSb cross section was also carried out. After 180 s thermal treatment at 600 ℃, the GaSb substrate can obtain a clean and relatively flat surface after most of the oxide is removed from the substrate surface, thus improving the crystallization quality of CdZnTe epitaxial film. The full width of half maximum of double crystal X-ray curve is 94″, which approached the crystalline quality of bulk CdZnTe crystal ever reported. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive study of hydrogenated amorphous silicon (a-Si)-based detectors, utilizing electrical characterization, Raman spectroscopy, photoemission, and inverse photoemission techniques. The unique properties of a-Si have sparked interest in its application for radiation detection in both physics and medicine. Although amorphous silicon (a-Si) is inherently a highly defective material, hydrogenation significantly reduces defect density, enabling its use in radiation detector devices. Spectroscopic measurements provide insights into the intricate relationship between the structure and electronic properties of a-Si, enhancing our understanding of how specific configurations, such as the choice of substrate, can markedly influence detector performance. In this study, we compare the performance of a-Si detectors deposited on two different substrates: crystalline silicon (c-Si) and flexible Kapton. Our findings suggest that detectors deposited on Kapton exhibit reduced sensitivity, despite having comparable noise and leakage current levels to those on crystalline silicon. We hypothesize that this discrepancy may be attributed to the substrate material, differences in film morphology, and/or the alignment of energy levels. Further measurements are planned to substantiate these hypotheses. [ABSTRACT FROM AUTHOR]

The in‐plane thermal conductivity of ultra‐thin films is of high interest due to its role in many technological applications, while being very challenging to measure. The challenge lies in creating a heat flow laterally through the thin sample film while eliminating all heat losses to the substrate and the surrounding air. A technique involving two parallel, line‐shaped resistance temperature detectors (RTDs) as a pair of heater and sensor on a nanometer‐thin suspended membrane, which minimizes heat losses to the substrate, has been recently introduced and numerically modeled. Herein, measurements employing two parallel line RTDs on a (164 ± 3) nm thin silicon nitride (SiNx) membrane for characterization of heat flux in electrically conductive polymer films are presented. On top of heater and RTD, silicon dioxide (SiO2) is used as a electrical passivation layer. (118 ± 35) nm poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) thin films are characterized. The methodology to enable these measurements starting from the fabrication of the devices using photolithography and chemical wet etching and the assembly of the high vacuum setup for precise measurements are discussed. Thermal conductivities of 2.9 ± 0.2 W m−1 K−1, 0.6 ± 0.2 W m−1 K−1, and 0.4 ± 0.8 W m−1 K−1 are measured for the SiNx, SiO2 and PEDOT:PSS thin films, respectively. Our findings can facilitate this flexible measurement method to other material systems. [ABSTRACT FROM AUTHOR]

By employing a co‐sputtering technique, combinatorial thin film libraries in the Ti–Zr system are produced. The libraries have a compositional spread ranging from 40 to 70 at% Ti. The confocal geometry of the sputtering system is maintained for the production of all thin films. The microstructural and crystallographic properties are elucidated by energy dispersive X‐ray spectroscopy (EDX), X‐ray diffraction (XRD), and scanning electron microscopy (SEM) analysis. Furthermore, contact angle measurements and nanoindentations are performed to map the wettability, hardness, and elastic modulus of the alloy system. The electrochemical properties, i.e., the oxide film formation factor and the relative permittivity of anodically grown oxides on the parent metal alloys are determined. The measurements are performed in phosphate‐buffered saline in order to best simulate a biological environment. A linear shift in the properties is observed along the compositional gradient for the EDX, XRD, and SEM analysis. For all other sets of measurements deviations from the linear behavior, are observed around the 60 at% Ti concentrations. This coincides with the formation of a congruent alloy in bulk material. The observed changes however, deviated also from expectations for bulk alloys. The implications and potential for those alloys as implant material are discussed in the following. [ABSTRACT FROM AUTHOR]

The size and electric field dependent induction of polarization in antiferroelectric ZrO2 is the key to several technological applications that are unimaginable a decade ago. However, the lack of a deeper understanding of the mechanism hinders progress. Molecular dynamics simulations of polycrystalline ZrO2, based on machine‐learned interatomic forces with near ab initio quality, shed light on the fundamental mechanism of the size effect on the transition fields. Stress in the oxygen sublattice is the most important factor. The so constructed interatomic forces allow the calculation of the transition fields as a function of the ZrO2 film thickness and predict the ferroelectricity at large thickness. The simulation results are validated with electrical and piezo response force microscopy measurements. The results allow a clear interpretation of the properties of the double‐hysteresis loops as well as the construction of the free energy landscape of ZrO2 grains. [ABSTRACT FROM AUTHOR]

Polymeric coating is one of the most used surface modification techniques on stents to reduce late stent thrombosis and restenosis. Coating process parameters must need to be rigorously controlled in biomedical applications. Spray coating is one of the most promising process used to recover commercial coronary stents, wherein uniform surfaces must be achieved. A novel low-cost spray coating machine was developed constructed using an airbrush with adjustable pressure (30 psi to 45 psi). Additionally, time and distance control systems were adapted for tubular samples, and a motor controlled their rotation. Polylactic acid (PLA) was deposited on 316L stainless steel tubes, using a spray coating technique for coronary stents purposes in order to achieve optimal film characteristics. Scanning electron microscopy was used to analyze the coating homogeneity. Other physical characteristics such as weight and surface roughness were measured to assess the feasibility of the proposed system. [ABSTRACT FROM AUTHOR]

This paper provides the design, construction, and characterization of a neutral density filter (NDF) for the visible spectrum and investigate the thickness effect on their various properties. In this work, Nichrome single layer was designed by the Essential Macleod modelling software. The Co-evaporation ofss nickel and chromium was used to construct a filter on a glass substrate by thermal vacuum coating unit under high vacuum. Low thickness supports amorphous nature examined by XRD diffractogram. Energy-Dispersive X-ray Spectroscopy (EDAX) examinations of the thin films revealed that high thickness has slight variation in constant stoichiometry for the chosen Nickel/Chromium ratio (80:20) during co-evaporation and confirm the deposition is successfully done. Additionally, Atomic Force Microscopy (AFM) analysis revealed that surface roughness decreased from 6.034 to 2.895 in correlation with increased layer thickness. These methods made it possible to produce NDFs with optical densities ranging from 0.5 OD at 10 nm film thickness to 2.7 OD at 70 nm thickness. As a result, for steady and long-lasting NDF, the spectral fluctuation of thin filters in our case is lowest at 10 nm (OD= 0.08). A good match data was found between optical transmission and absorption spectra of the designed and the deposited films. The designed NDF's applicability and effectiveness for color sorting tasks were subsequently examined, marking a promising step towards advancing optical engineering solutions in this specific application domain. [ABSTRACT FROM AUTHOR]

LiNbO3 thin films are grown on a c-plane (0001) sapphire wafer at a relatively low substrate temperature by chemical beam vapor deposition (CBVD) in Sybilla equipment. Raman measurements only evidence the LiNbO3 phase, while HR-XRD diffractograms demonstrate a c-axis-oriented growth with only (006) and (0012) planes measured. The rocking curve is symmetric, with a full width at half maximum (FWHM) of 0.04°. The morphology and topography observed by SEM and AFM show very low roughness, with rms equaling 2.0 nm. The optical properties are investigated by a guided-wave technique using prism coupling. The ordinary refractive index (no) and extraordinary refractive index (ne) at different wavelengths totally match with the LiNbO3 bulk, showing the high microstructural quality of the film. The film composition is estimated by Raman and bi-refringence and shows a congruent or near-stoichiometric LiNbO3. [ABSTRACT FROM AUTHOR]

Integrating two-dimensional layered supercell (LSC) oxides and plasmonic Au nanostructures into one hybrid framework can open up multifunctionality tuning into a new level. In this work, Bi-based LSCs Bi3Fe2Mn2Ox and Bi2WO6 incorporated with secondary plasmonic Au and/or ferromagnetic La0.7Sr0.3MnO3 phases have been grown via pulsed laser deposition (PLD). Microstructural characterization results show the highly epitaxy film quality and distinct LSC structures despite the incorporated secondary phases. The nanocomposite films exhibit multiferroic and plasmonic responses due to the multi-phase coupling. This work provides a new approach of integrating self-assembled LSC-metal/oxide nanocomposite thin films for future multiferroics and spintronics device applications. [ABSTRACT FROM AUTHOR]

Understanding surface stability becomes critical as 2D materials like SnSe are developed for piezoelectric and optical applications. SnSe thin films deposited by molecular beam epitaxy showed no structural changes after a two-year exposure to atmosphere, as confirmed by X-ray diffraction and Raman spectroscopy. X-ray photoelectron spectroscopy and reflectivity show a stable 3.5 nm surface oxide layer, indicating a self-arresting oxidative process. Resistivity measurements show an electrical response dominated by SnSe post-exposure. This work shows that SnSe films can be used in ambient conditions with minimal risk of long-term degradation, which is critical for the development of piezoelectric or photovoltaic devices. [ABSTRACT FROM AUTHOR]

We described optical properties of zinc oxide (ZnO) nanoparticles determined by spectroscopic ellipsometry analysis from ex situ spectroscopic ellipsometry (ex situ SE) measurements made on nanocrystalline thin films over a spectral range of 0.734 to 4.00 eV. We determined the complex refractive index function, n ~ (ω) = n (ω) + i κ (ω) , by fitting a layered parametric model to the ellipsometric measurements. We collected SE measurements at an incidence angle of 70°. We also determined absorption coefficient spectra using extinction coefficient, κ and wavelength, λ. The direct optical bandgap of the films was obtained as 3.2 eV using the ellipsometric method. [ABSTRACT FROM AUTHOR]

Brain-computer interfaces (BCIs) represent a cutting-edge field in neuroengineering, facilitating direct communication between the brain and external devices. With applications ranging from the study of neuroscience to medical diagnosis and therapy, virtual reality, and cognitive augmentation, BCIs are at the forefront of technological advancement. Traditional rigid neural probes used in BCIs face challenges in maintaining long-term, stable recordings at the single-neuron level. Furthermore, achieving high electrode density while minimizing flexural rigidity remains a challenge with conventional rigid materials. In this perspective, we emphasize the importance of spatiotemporal scalability in the advancement of neural probes. We discuss the necessary material properties to achieve high spatiotemporal scalability, which is critical for long-term stability in neural recordings and for increasing electrode counts and density. We review recent developments in flexible and soft material systems, as well as fabrication strategies to meet these challenges. Our analysis highlights the potential of flexible and soft electronics to overcome existing limitations and realize the full potential of next-generation BCIs. [ABSTRACT FROM AUTHOR]

With the advancement of semiconductor manufacturing technology, thin film structures were widely used in MEMS devices. These films played critical roles in providing support, reinforcement, and insulation in MEMS devices. However, due to their microscopic dimensions, the sensitivity of their parameters and performance to thermal stress increased significantly. In this study, a Pirani gauge sample with a multilayer thin film structure was designed and fabricated. Based on this sample, finite element modeling analysis and thermal stress experiments were conducted. The finite element modeling analysis employed a combination of steady-state and transient methods to simulate the deformation and stress distribution of the device at room temperature (25 °C), low temperature (−55 °C), and high temperature (125 °C). The thermal stress test involved placing the sample in a temperature cycling chamber for temperature cycling tests. After the tests, the resonant frequency and surface deformation of the device were measured to quantitatively evaluate the impact of thermal stress on the deformation and resonant frequency parameters of the device. After the experiments, it was found that the clamped-end beams made of Pt were a stress concentration area. Additionally, the repetitive thermal load caused the cantilever beam to move cyclically in the Z direction. This movement altered the deformation of the film and the resonant frequency. The suspended film exhibited concavity, and the overall trend of the resonant frequency was downward. Over time, this could even lead to the fracture of the clamped-end beams. The variation of mechanical parameters derived from finite element simulations and experiments provided an important reference value for device design improvement and played a crucial role in enhancing the reliability of thin film devices. [ABSTRACT FROM AUTHOR]

Cadmium telluride is an efficient light absorbing material successfully used in solar cell technology. The efficiency of such photovoltaic devices is strongly dependent on post‐deposition thermal treatments in the presence of chlorine. The benefits of this process on the absorbing layer include removal of intragrain defects, grain growth enhancement, and grain boundaries passivation. The absorber chlorination is a crucial step for which CdCl2 is the most common choice. Its use, however, has been overshadowed by the toxicity of Cd‐ and Cl‐containing vapors and residues. In this work, chlorine was incorporated in CdTe films during growth using sputtering targets with different chloride compounds: CdCl2, TeCl4, BaCl2, CaCl2, or LiCl. After characterizing these films, CdTe:CdCl2 and CdTe:TeCl4 were selected as feasible absorbers for testing their performance in photovoltaic devices. Efficiencies near 7% were obtained in as‐grown unoptimized cells in which the absorber consisted of two layers: pristine CdTe and CdTe:CdCl2 or CdTe:TeCl4. The chlorinated layers acted as Cl sources for the adjacent CdTe and CdS, which produced a homogeneous distribution of chlorine throughout the cell. In the during‐growth activating‐layer (DG‐AL) method used here, the chlorine diffusion during growth had a doping effect, passivated grain boundaries and defects, improved the back contact characteristics by reducing the CdTe work function, and lowered the pinhole formation probability by producing a compact chlorinated CdTe layer. [ABSTRACT FROM AUTHOR]

The size and electric field dependent induction of polarization in antiferroelectric ZrO2 is the key to several technological applications that are unimaginable a decade ago. However, the lack of a deeper understanding of the mechanism hinders progress. Molecular dynamics simulations of polycrystalline ZrO2, based on machine‐learned interatomic forces with near ab initio quality, shed light on the fundamental mechanism of the size effect on the transition fields. Stress in the oxygen sublattice is the most important factor. The so constructed interatomic forces allow the calculation of the transition fields as a function of the ZrO2 film thickness and predict the ferroelectricity at large thickness. The simulation results are validated with electrical and piezo response force microscopy measurements. The results allow a clear interpretation of the properties of the double‐hysteresis loops as well as the construction of the free energy landscape of ZrO2 grains. [ABSTRACT FROM AUTHOR]

Electrochromic materials enable the precise control of their optical properties, making them essential for energy-saving applications such as smart windows. This study focuses on the synthesis of molybdenum-doped niobium oxide (Mo-Nb2O5) thin films using a one-step hydrothermal method to investigate the effect of Mo doping on the material's electrochromic performance. Mo incorporation led to distinct morphological changes and a transition from a compact granular structure to an anisotropic rod-like feature. Notably, the MN-3 (0.3% Mo) sample displayed an optimal electrochromic performance, achieving 77% optical modulation at 600 nm, a near-perfect reversibility of 99%, and a high coloration efficiency of 89 cm2/C. Additionally, MN-3 exhibited excellent cycling stability, with only 0.8% degradation over 5000 s. The MN-3 device also displayed impressive control over color switching, underscoring its potential for practical applications. These results highlight the significant impact of Mo doping on improving the structural and electrochromic properties of Nb2O5 thin films, offering improved ion intercalation and charge transport. This study underscores the potential of Mo-Nb2O5 for practical applications in energy-efficient technologies. [ABSTRACT FROM AUTHOR]

Since the Nobel prize winning discovery that polyacetylene could act as a semiconductor, there has been tremendous efforts dedicated to understanding and harnessing the unusual properties of π‐conjugated polymers. Much of this research has focused on the preparation of oligoynes and polyynes with well‐defined numbers of repeating alkyne units as models for carbyne. These studies are usually hampered by a structure‐property relationship where the stability of the resulting materials decrease with the incorporation of additional alkyne units. Here, we describe a series of oligoynes, with up to 12 alkyne units, where electron‐rich [Pt(PBu3)2]2+ units are incorporated at the center of the oligoyne backbones which are capped by electron‐poor BF2 formazanate dyes. These compounds exhibit excellent stability and solubility, panchromatic absorption, and redox activity characteristic of their structural components. These traits facilitated thin‐film studies of extended oligoyne materials, where it is shown that incorporating [Pt(PBu3)2]2+ units leads to smoother films, decreased conductivity on the microscale, and increased conductivity on the nanoscale when compared to metal‐free analogs. Remarkably, our oligoynes have superior conductivity compared to the ubiquitous poly(3‐hexylthiophene) semiconductor. [ABSTRACT FROM AUTHOR]

Kesterite Cu2ZnSnS4 (CZTS) solar cells with CdS buffer layers have the problem of toxicity and cliff‐like energy band diagram disfavoring higher photoelectric conversion efficiency (PCE (%)). The preparation method for ZnSnO buffer layers which enable Cd‐free CZTS solar cells to reach the certified PCE (%) of 11.4 is limited to atomic layer deposition and sputtering deposition severely reduces PCE (%). Here, it is showed that sputtering deposited ZnSnN2 is an efficient buffer layer for Cd‐free CZTS solar cell, and without antireflection coating or additional passivation layers its champion PCE (%) has reached 10.00 which is comparable to the certified value. No buried junction and current blocking behavior are observed in the CZTS\ZnSnN2 junctions. Elemental inter‐diffusion is observed at the interface between CZTS and ZnSnN2. Most importantly, the energy band of ZnSnN2 is well‐matched with that of CZTS. The former straddles the latter. The conduction band offset is spike‐like with the conduction band of ZnSnN2 higher than that of CZTS, which effectively suppresses interface recombination and results in PCE (%) comparable to the certified value. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid thermoelectric (TE) materials have attracted tremendous interest for harvesting waste heat energy. Due to their mechanical flexibility, inorganic‐organic hybrid TE materials are considered to be promising candidates for flexible energy harvesting devices. In this work, enhanced TE properties of Tellurium (Te) nanowires (NWs)‐ poly (3‐hexylthiophene‐2, 5‐diyl) (P3HT) hybrid materials are reported by improving the charge transport at interfacial layer mediated via controlled oxidation. A power factor of ≈9.8 µW (mK2)−1 is obtained at room temperature for oxidized P3HT‐TeNWs hybrid materials, which increases to ≈64.8 µW (mK2)−1 upon control of TeNWs oxidation. This value is sevenfold higher compared to P3HT‐TeNWs‐based hybrid materials reported in the literature. MD simulation reveals that oxidation‐free TeNWs demonstrate better templating for P3HT polymer compared to oxidized TeNWs. The Kang–Snyder model is used to study the charge transport in these hybrid materials. A large σE0 value is obtained which is related to better templating of P3HT on oxygen‐free TeNWs. This work provides evidence that oxidation control of TeNWs is critical for better interface‐driven charge transport, which enhances the thermoelectric properties of TeNWs‐P3HT hybrid materials. This work provides a new avenue to improve the thermoelectric properties of a new class of hybrid thermoelectric materials. [ABSTRACT FROM AUTHOR]