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5 figures, 1 table.-- Supporting information available., Nanoparticles (NPs) of conjugated polymers in intimate contact with sheets of graphene oxide (GO) constitute a promising class of water-dispersible nanohybrid materials of increased interest for the design of sustainable and improved optoelectronic thin-film devices, revealing properties exclusively pre-established upon their liquid-phase synthesis. In this context, we report for the first time the preparation of a P3HTNPs–GO nanohybrid employing a miniemulsion synthesis approach, whereby GO sheets dispersed in the aqueous phase serve as a surfactant. We show that this process uniquely favors a quinoid-like conformation of the P3HT chains of the resulting NPs well located onto individual GO sheets. The accompanied change in the electronic behavior of these P3HTNPs, consistently confirmed by the photoluminescence and Raman response of the hybrid in the liquid and solid states, respectively, as well as by the properties of the surface potential of isolated individual P3HTNPs–GO nano-objects, facilitates unprecedented charge transfer interactions between the two constituents. While the electrochemical performance of nanohybrid films is featured by fast charge transfer processes, compared to those taking place in pure P3HTNPs films, the loss of electrochromic effects in P3HTNPs–GO films additionally indicates the unusual suppression of polaronic charge transport processes typically encountered in P3HT. Thus, the established interface interactions in the P3HTNPs–GO hybrid enable a direct and highly efficient charge extraction channel via GO sheets. These findings are of relevance for the sustainable design of novel high-performance optoelectronic device structures based on water-dispersible conjugated polymer nanoparticles., This work was funded by Spanish MCIN/AEI/10.13039/501100011033 under projects PID2019-104272RB-C51, PID2019-104272RB-C52, PID2019-104272RB-C55, and PID2019-104739GB-I00. Financial support from Gobierno de Aragon (DGA) under project “Grupos Consolidados” T03_20R is acknowledged. E.C. is grateful for PhD grant BES2017-080020 funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”. M.N.R.’s work was financed by grant PID2019-104272RB-C52/PRE2020-094503 funded by MCIN/AEI/10.13039/501100011033 and by “‘ESF Investing in your future”’. R.A. acknowledges support from EU H2020 “ESTEEM3” (Grant number 823717) and Graphene Flagship (881603).

In the present study, we propose a new transparent thin-film ITO surface radio-frequency (RF) trap. Charged hybrid microstructures were localized in the developed ITO trap. We show, analytically and experimentally, that the position of the localization zones in the trapped hybrid structure are stable. The transfer of charged particles between localization zones was studied under the action of gravity-compensating laser radiation. We highlight the advantages of transparent thin-film ITO traps to investigate and manipulate charged particles.

[Abstract] Emergent bioelectronic technologies are underpinned by the organic electrochemical transistor (OECT), which employs an electrolyte medium to modulate the conductivity of its organic semiconductor channel. Here we utilize postpolymerization modification (PPM) on a conjugated polymer backbone to directly introduce glycolated or anionic side chains via fluoride displacement. The resulting polymers demonstrated increased volumetric capacitances, with subdued swelling, compared to their parent polymer in p-type enhancement mode OECTs. This increase in capacitance was attributed to their modified side chain configurations enabling cationic charge compensation for thin film electrochemical oxidation, as deduced from electrochemical quartz crystal microbalance measurements. An overall improvement in OECT performance was recorded for the hybrid glycol/ionic polymer compared to the parent, owing to its low swelling and bimodal crystalline orientation as imaged by grazing-incidence wide-angle X-ray scattering, enabling its high charge mobility at 1.02 cm2·V–1·s–1. Compromised device performance was recorded for the fully glycolated derivative compared to the parent, which was linked to its limited face-on stacking, which hindered OECT charge mobility at 0.26 cm2·V–1·s–1, despite its high capacitance. These results highlight the effectiveness of anionic side chain attachment by PPM as a means of increasing the volumetric capacitance of p-type conjugated polymers for OECTs, while retaining solid-state macromolecular properties that facilitate hole transport. Reino Unido. Engineering and Physical Sciences Research Council; EP/T028513/1 República de Corea. Global Research Laboratory program; NRF-2017K1A1A2013153 República de Corea. National Research Foundation of Korea; RF-2021R1A2C101301511 569 República de Corea. National Research Foundation of Korea; 2021R1A2C1013015 República de Corea. National Research Foundation of Korea; 2018M3A7B4070988 República de Corea. National Research Foundation of Korea; 2021R1A4A1022920

Nitrides of aluminum (Al) and titanium (Ti) mixtures have long been studied and used as commercial coatings because of their high hardness and high oxidation resistance due to the formation of an alumina layer on the coating surface. To fully understand the contribution of Al and Ti to the properties of the film, a combinatorial deposition approach was employed using half-disk targets. Film growth was carried out using a magnetron sputtering system powered by a 13.56 MHz radio frequency power supply with varying argon (Ar) and nitrogen (N2) gas ratios. Depending on the location of the substrate relative to the target, atomic percent gradients of 0.60–0.70 Al and 0.30–0.40 Ti across the substrate surface were obtained from energy dispersive X-ray spectral analysis. X-ray diffraction peaks at 43.59°, 74.71° (face-centered cubic), and 50.60° (wurtzite) confirmed the presence of aluminum titanium nitride (AlTiN) mixtures, with an increasing amount of wurtzite phase at higher Al concentrations. For all samples, cauliflower-like nanograins were obtained and samples of the 80:20 Ar:N2 gas pressure ratio showed the smallest grain size among the three gas ratio combinations. The 80:20 Ar:N2 films revealed a relatively high hardness compared to the other gas ratios. All thin films exhibited good adhesion to 304 stainless steel substrates.

Magnetic small‐angle neutron scattering (SANS) is ideally suited to providing direct reciprocal‐space information on long‐wavelength magnetic modulations, such as helicoids, solitons, merons or skyrmions. SANS of such structures in thin films or micro‐structured bulk materials is strongly limited by the tiny scattering volume vis a vis the prohibitively high background scattering by the substrate and support structures. Considering near‐surface scattering just above the critical angle of reflection, where unwanted signal contributions due to substrate or support structures become very small, it is established that the scattering patterns of the helical, conical, skyrmion lattice and fluctuation‐disordered phases in a polished bulk sample of MnSi are equivalent for conventional transmission and near‐surface SANS geometries. This motivates the prediction of a complete repository of scattering patterns expected for thin films in the near‐surface SANS geometry for each orientation of the magnetic order with respect to the scattering plane., Near‐surface SANS is discussed for its potential as a probe of long‐wavelength magnetic modulations in specimens with reduced sample dimensions.

Pure and nickel doped copper oxide thin films were successfully grown on a soda lime glass substrates including various amounts (1, 2, 4, and 8%) of nickel dopants via ultrasonic spray pyrolysis method. The effects of the different impurity doping concentrations on the structural, morphological, optical, and H2 gas sensing properties of the prepared samples were assessed by performing X-ray Diffraction, scanning electron microscopy, ultraviolet–visible spectroscopy, photoluminescence spectroscopy, gas sensing measurements, and X-ray photoelectron spectroscopy. The structural observations revealed that the grown films have polycrystalline nature with monoclinic cubic crystal structure of copper oxide with no secondary phases present, and grain sizes increased in general as the doping percentage increased except for the 4% nickel doped sample. The morphological analysis showed that the impurities clearly led to modifications in the shapes of the grown copper oxide nanocrystals. In the optical measurements, it was uncovered that the ideal impurity level can enhance the absorbance features of the copper oxide material, and a slight increase in bandgap occurred due to the first level of impurity doping, but then the bandgap decreased as the impurity contents increased. A gradual decrease in the intensity of luminescent emissions was observed in the photoluminescence spectra as the doping concentration increased, which may be associated with the defects caused by the added nickel ions into the copper oxide lattices. Gas sensor measurements disclosed that the produced films were responsive when exposed to H2 gas, and enhanced responsivity was realized by the nickel doping compared to that of pure copper oxide sample. X-ray photoelectron spectroscopy confirmed the presence of aimed chemical compositions in the prepared thin films. © 2022 Hydrogen Energy Publications LLC

We report a method for the directed self-assembly (DSA) of block copolymers (BCPs) in which a first BCP film deploys homopolymer brushes, or "inks", that sequentially graft onto the substrate's surface via the interpenetration of polymer molecules during the thermal annealing of the polymer film on top of existing polymer brushes. By selecting polymer "inks" with the desired chemistry and appropriate relative molecular weights, it is possible to use brush interpenetration as a powerful technique to generate self-registered chemical contrast patterns at the same frequency as that of the domains of the BCP. The result is a process with a higher tolerance to dimensional and chemical imperfections in the guiding patterns, which we showcase by implementing DSA using homopolymer brushes for the guiding features as opposed to more robust cross-linkable mats. We find that the use of "inks" does not compromise the line width roughness, and the quality of the DSA as a lithographic mask is verified by implementing a robust "dry lift-off" pattern transfer.

A patterned carbon film was produced from Linear Low-Density Polyethylene (LLDPE) by the implementation of a novel method named Chemical Masking Perforation (CMP). The following paper describes this procedure, starting with the sulfonation of the precursor polymer LLDPE with Chlorosulphonic acid to stabilize the material, followed by Fourier-transform infrared spectroscopy (FTIR) evaluation to compare the atomic bonds from the stabilized film as well as from the masked sections of the film. To finalize, the cross-linked film was carbonized in an oven at 950 °C. The outcome of this process was a carbon film with a thickness similar to a carbon fiber diameter of 8 µm with controllable size and distribution.

International audience; We report on the fabrication, characterization, and microthermometry application of high-quality, nanometric thin films, with thicknesses in the range 20–200 nm, of the molecular spin-crossover complex [Fe(HB(1,2,3-triazol-1-yl)3)2]. The films were obtained by vacuum thermal evaporation and characterized by X-ray diffraction, UV spectrophotometry, and atomic force microscopy. The as-deposited films are dense and crystalline with a preferred [011] orientation of the monoclinic crystal lattice normal to the substrate surface. The films exhibit a gradual spin conversion centered at ca. 374 K spanning the 273–473 K temperature range, irrespective of their thickness. When deposited on a microelectronic device, these films can be used to enhance the UV-light thermoreflectance coefficient of reflective surfaces by more than an order of magnitude, allowing for high-sensitivity thermoreflectance thermal imaging.

International audience; This review is dedicated to various functional nanoarchitectonic nanocomposites based on molecular octahedral metal atom clusters (Nb-6, Mo-6, Ta-6, W-6, Re-6). Powder and film nanocomposites with two-dimensional, one-dimensional and zero-dimensional morphologies are presented, as well as film matrices from organic polymers to inorganic layered oxides. The high potential and synergetic effects of these nanocomposites for biotechnology applications, photovoltaic, solar control, catalytic, photonic and sensor applications are demonstrated. This review also provides a basic level of understanding how nanocomposites are characterized and processed using different techniques and methods. The main objective of this review would be to provide guiding significance for the design of new high-performance nanocomposites based on transition metal atom clusters.

A study of ZnO-based ceramic films prepared by the spray-pyrolysis technique is presented. Pure and Ni-doped thin film samples were deposited as a coating on a glass substrate and experimentally characterized using scanning electron and atomic force microscopies, X-ray diffraction, and UV-vis-NIR spectroscopy. The morphologic, crystallographic, and optical properties were analyzed. Structural and electronic properties were compared to predictions obtained from computational calculations based on the density functional theory plus U approach (DFT+U). All these simulations provided additional data that could be used as a reference for material modeling and a better understanding of the experimental results. It was found that spray pyrolysis can be used to produce thin film ceramic samples (~300 nm) with low amounts (

Hydrotalcites (HTlcs) are a class of nanostructured layered materials that may be employed in a variety of applications, from green to bio technologies. In this paper, we report an investigation on HTlcs made of Mg and Fe, recently employed to improve the growth in vitro of osteoblasts within a keratin sponge. We carried out an analysis of powder materials and of HTlcs dispersed in keratin and spin-coated on a Si/SiO2 substrate at different temperatures. A magnetic study of the powders was carried out with a Quantum Design Physical Property Measurement System equipped with a Vibrating Sample Magnetometer. The data gathered prove that these HTlcs are fully paramagnetic, and keratin showed a very small magnetic response. Optical and Atomic Force Microscopy analyses of the thin films provide a detailed picture of clusters randomly dispersed in the films with various dimensions. The magnetic properties of these films were characterized using the Nano Magneto Optical Kerr Effect (NanoMOKE) down to 7.5 K. The data collected show that the local magnetic properties can be mapped with a micrometric resolution distinguishing HTlc regions from keratin ones. This approach opens new perspectives in the characterization of these composite materials.

Supersonic jets of metal vapors with carrier gas are promising for producing nanostructured metal films at relatively low source temperatures and high deposition rates. However, the effects of the carrier gas on the jet composition and expansion dynamics, as well as on film properties, remain virtually unexplored. In this work, the free-jet expansion of a mixture of silver vapor with helium in a rarefied regime at an initial temperature of 1373 K is investigated through mass spectrometry and direct-simulation Monte Carlo methods. Introducing the carrier gas into the source is found to result in a transition from a collisionless to a collision-dominated expansion regime and dramatic changes in the Ag jet, which becomes denser, faster, and more forward-directed. The changes are shown to be favorable for the formation of small Ag clusters and film deposition. At a fairly high helium flow, silver Ag2 dimers are observed in the jet, both in the experiment and the simulations, with a mole fraction reaching 0.1%. The terminal velocities of silver atoms and dimers are nearly identical, indicating that the clusters are likely formed due to the condensation of silver vapor in the expanding jet. A high potential of supersonic Ag-He jets for the deposition of nanostructured silver films is demonstrated. The deposited jet Ag2 dimers appear to serve as nucleation centers and, thus, allow for controlling the size of the produced surface nanostructures.

Etching of steel items in sulfuric acid solution is used in various human activities (oil and gas industry, metal production, utilities, transport, etc.). This operation is associated with significant material costs due to corrosion losses of the metal. It has been found that an efficient way to prevent corrosion of steel in sulfuric acid solution involves the formation of thin protective films consisting of corrosion inhibitor molecules of triazole class on its surface. It has been shown that the protection of steels with a 3-substituted 1,2,4-triazole (3ST) in H2SO4 solution is accompanied by the formation of a polymolecular layer up to 4 nm thick. The 3ST layer immediately adjacent to the steel surface is chemisorbed on it. The efficiency of this compound as an inhibitor of corrosion and hydrogen absorption by steel is determined by its ability to form a protective organic layer, as experimentally confirmed by XPS and AFM data. The kinetic constants of the main stages of hydrogen evolution and permeation into steel in the H2SO4 solution were determined. A significant decrease in both the reaction rate of cathodic hydrogen evolution and the rate of hydrogen permeation into steel by the triazole in question was noted. It has been shown that the preservation of the metal plasticity in the acid medium containing the triazole under study is due to a decrease in the hydrogen concentration in the metal bulk.

In the era of developing wearable electronics, the miniaturization of electronic systems and their implementation in the textile industry is one of the key issues. For this reason, it is important to select the appropriate textile substrates upon which it is possible to produce electroconductive structures, as well as their selection from the point of view of the electrical parameters’ stability. For this purpose, research related to the effect of heating a substrate on the resistance of the structures produced in the process of physical vacuum planting was conducted. Textile composites with a buffer layer made of polyurethane, Teflon, and acrylic were used as substrates in the tests. Such layers are an integral part of textile composites and a necessary element for producing structures with continuous electrical conductivity. The conducted tests showed that a buffer layer made of polyurethane (thermal conductivity, e.g., PERMACOL 5450 resin 0.16 W/mK) heated to 15 °C above room temperature was a layer that introduced changes into the surface resistance of the structures. The resistance values of the samples produced on a substrate containing a buffer layer of polyurethane varied in the range of 9–23%, depending on the manufacturer of the composite in the case of a self-heating mode, and in the case of an external heating mode, these changes were smaller and ranged from 8 to 16%. Such a phenomenon occurred regardless of the type of applied metal, and this was not observed in the case of composites with a Teflon or acrylic sublayer. For this reason, it is necessary to take into account the fact that textronic structures made on substrates containing a polyurethane layer may change the surface resistance depending on the temperature. The electrical parameters of such structures were checked by heating the structure using an external heater and self-heating mechanism. The same phenomenon was observed in both cases.

High-entropy alloys are promising materials for novel thin-film resistors since they have high resistivity and a low-temperature coefficient of resistivity (TCR). In this work, a new high-entropy thin-film CoCrFeNiTix was deposited on a Si/SiO2 substrate by means of magnetron sputtering of the multi-component target produced by hot pressing of the powder mixture. The samples possessed a thickness of 130–230 nm and an amorphous atomic structure with nanocrystallite traces. This structure persisted after being annealed up to 400 °C, which was confirmed using X-ray and electron diffraction. The film had a single-phase structure with a smooth surface and a uniform distribution of all elements. The obtained film served for microresistor elaboration, which was produced using the lithography technique and tested in a temperature range from −60 °C up to 200 °C. Resistivity at room temperature was estimated as 2.37 μOhm·m. The results have demonstrated that TCR depends on temperature according to the simple linear law in a range from −60 °C up to 130 °C, changing its value from −78 ppm/°C at low temperatures to −6.6 ppm/°C at 130 °C. Such characteristics show the possibility of using these high-entropy alloy films for resistive elements in contemporary and future micro-electronic devices.

Zinc oxide exhibits unique properties that are reflected in a wide variety of applications, particularly in the field of transparent, conductive films. However, less attention has been paid to their color. Here, we present the synthesis of yellow-gray ZnO films at room temperature by femtosecond pulsed laser deposition. In situ Raman investigations of these polycrystalline ZnO films reveal the existence of superoxide ions, O2−, in zinc oxide, which are responsible for the yellow color, and are also detected in ZnO powder and single crystals. In addition, further dioxygen species are identified in the samples, including the O2-molecule. The negative charge excess caused by the dioxygen species creates metallic zinc as a byproduct. Structural analysis reveals an unforced realization of the dioxygen species in the ZnO lattice. Density functional theory (DFT) calculations support the assumed structural displacements as well as the observed, unexpected Raman bands. These results open up completely new insights into the behavior of ZnO.

The processability of organic thermoelectric materials plays a crucial role due to their clear advantages of applicability in large-scale areas compared to traditional inorganic counterparts. A promising way to process thermoelectric materials based on conductive polymers is through in situ polymerization in an insulating polymer matrix. This work shows an interpenetrating polymeric network based on polythiophene, silver nanoparticles (Ag NPs), and poly(methyl methacrylate) (PMMA) produced by the oxidative polymerization of terthiophene by an oxidizing silver salt in a PMMA matrix. Ag NPs are in situ synthesized simultaneously as a byproduct. The reaction occurs very fast in the solid state, and after only 1 min, a homogeneous interpenetrating polymer network (IPN) film is obtained, reaching electrical conductivity values of 120 S cm–1. Ag NPs play a determining role in the conducting properties of the IPN. Moreover, the thermoelectric properties were evaluated as a function of the synthesis parameters, reaching a maximum power factor of 51 μW m–1 K–2. This study shows a promising method to enhance the processability of hybrid thermoelectric materials on the basis of conductive polymers and nanofillers.

Catalysis today 376, S0920586121002856 (1-10) (2021). doi:10.1016/j.cattod.2021.06.018, The objective of this research was to investigate how the photocatalytic activity of pure TiO$_2$ can be improved bySnO$_2$ modification. Different molar ratios of tin to titanium were prepared. The correlation between tin concentration and structural properties was investigated to explain the mechanism of photocatalytic efficiency and to optimize the synthesis conditions to obtain enhanced activity of the SnO$_2$-modified TiO$_2$ photocatalysts under UV-irradiation. The SnO$_2$-modified TiO$_2$ photocatalysts were prepared by a low-temperature sol-gel method based on organic tin and titanium precursors. The precursors underwent sol-gel reactions separately to form SnO$_2$-TiO$_2$ sol. The sol-gels were deposited on a glass substrate by a dip-coating technique and dried at 150 °C to obtain the photocatalysts in the form of a thin film. To test the thermal stability of the material, an additional set of photocatalysts was prepared by calcining the dried samples in air at 500 °C. The photocatalytic activity of the samples was determined by measuring the degradation rate of an azo dye. An increase of up to 30% in thephotocatalytic activity of the air-dried samples was obtained when the TiO$_2$ was modified with the SnO$_2$ in a concentration range of 0.1–1 mol.%. At higher SnO$_2$ loadings, the photocatalytic activity of the photocatalystwas reduced compared to the unmodified TiO$_2$. The calcined samples showed an overall reduced photocatalyticactivity compared to the air-dried samples. Various characterization techniques (UV-Vis, XRD, N2-physisorption,TEM, EDX, SEM, XAS and photoelectrochemical characterization) were used to explain the mechanism for the enhanced and hindered photocatalytic performances of the SnO$_2$-modified TiO$_2$ photocatalysts. The results showed that the nanocrystalline cassiterite SnO$_2$ is attached to the TiO$_2$ nanocrystallites through the Sn-O-Ti bonds. In this way, the coupling of two semiconductors, SnO$_2$ and TiO$_2$, was demonstrated. Compared to single-phase photocatalysts, the coupling of semiconductors has a beneficial effect on the separation of charge carriers, which prolongs their lifetime for accessibility to participate in the redox reactions. The maximum increase in activity of the thin films was achieved in the low concentration range (0.1–1 mol.%), which means that an optimal ratio and contact of the two phases is achieved for the given physical parameters such as particle size, shape and specific surface area of the catalyst., Published by Elsevier, Amsterdam

Antimony triselenide (Sb2Se3) is one of the most promising absorber material choices among the inorganic semiconductors that has attracted much attention today. However, highest recorded efficiencies for Sb2Se3 solar cells are still lower than ideal. Exploring antimony selenosulfide (Sb-2(SxSe1-x)(3)) to increase device performance is one option because some features of alloyed Sb-2(SxSe1-x)(3) depend on composition such as bandgap and band position. In this study, two-step process was used to grow Sb-2(SxSe1-x)(3) thin films. In the first stage, Sb2Se3 thin films were deposited on soda lime glass substrates using direct current magnetron sputtering technique. In the second stage, Sb2Se3 thin films were exposed to sulfurization process in a quartz ampoule to obtain Sb-2(SxSe1-x)(3) thin films. Characterization results showed that morphological, optical, and structural properties of Sb-2(SxSe1-x)(3) thin films grown by presented method were highly dependent on amount of sulfur in the films. By the adjustment of the S/S + Se atomic ratio, Sb-2(SxSe1-x)(3) absorber materials with suitable bandgap, favorable orientation and compact morphology can be obtained for photovoltaic applications.

Thermoelectric energy conversion attracts increasing attention as a technology for effectively reusing waste heat. Although thermoelectric materials that show a good thermoelectric figure of merit (ZT) have been proposed thus far, they are not practical at all because they are thermally and chemically unstable and composed of toxic elements. In order to address this issue, the author focused on metal oxides as thermoelectric materials that are thermally and chemically stable and non-toxic, and succeeded in significantly improving thermoelectric ZT by using two-dimensional electron gas and elemental substitution. In 2007, the author focused on Prof. Dresselhaus's theory that by confining carriers in a quantum well thinner than the thermal de Broglie wavelength, the thermoelectric power can be greatly enhanced without lowering the conductivity, and the oxide superlattice was introduced. In 2010, the author demonstrated a field-effect transistor structure on an insulator SrTiO3 crystal and measured thermopower while inducing 2DEG with a thickness of 2 nm by applying a voltage, similar to an artificial superlattice. It was discovered that the thermoelectric field can be increased 5 times as much as the bulk ratio. Furthermore, in 2020, the author found that the Ba1/3CoO2 thin film with a layered crystal structure had the highest room temperature ZT of 0.11 among metal oxides. (C) 2022 The Ceramic Society of Japan. All rights reserved.

The processes at the interface between ionic liquids (ILs) and metals are a key factor for understanding especially in electrochemical deposition, nanoscale tribology applications and batteries. In the present work, the interfaces of 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Py1,4]TFSI) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm]TFSI) and platinum and aluminum were investigated by depositing thin IL films and studying them with X-ray photoelectron spectroscopy (XPS) in ultrahigh vacuum. It is found that there is no evidence of a decomposition reaction of either IL on platinum; however, the imidazolium cation of [EMIm]TFSI shows a strong interaction with the surface in the monolayer regime. In contrast, [Py1,4]TFSI and [EMIm]TFSI show massive decomposition on the aluminum surface without applying any electrochemical potential. The spectra for the [TFSI]− anion components show cleavage of C-F or N-S bonds in both cases. Both cleavage of a single fluorine atom and complete cleavage were observed, leading to further decomposition reactions of the anion. Consequently, new components such as AlOOH, Al(OH)3, Al2S3, Al2(SO4)3 and AlF3 appear at the interface. In addition, there is also evidence of decomposition of the cation by the splitting off hydrogen atoms or parts of the alkyl chain in both ILs.

The effects of copper concentration on the properties of copper lead sulfide thin films have been reported. Chemical bath deposition (CBD) method was used to deposit the ternary material on soda-lime substrates. Here, the films were grown using copper(II) chloride, lead nitrate, and thiourea as sources of copper (Cu), lead (Pb) and sulfur (S), respectively. The grown films were examined using X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, UV-spectrophotometer and four-point (4P) probes. XRD measurements revealed a polycrystalline material with strong adherent to the substrates. SEM readings indicated various grain-like crystalline morphologies with different sizes that change with copper concentrations. The EDX studies revealed that the deposited material consist of copper, lead and sulfur in various compositions. The transmittance was high in the near infrared regions of the electromagnetic radiation and, also decreases with copper concentrations. The band gap (Eg) varies from 2.05 to 2.50 eV with increase in copper concentrations. The study shows that CBD is an excellent method in depositing good quality films for device applications. KEY WORDS: Thin films, Substrates, Copper lead sulfide, Deposition, Optical properties Bull. Chem. Soc. Ethiop. 2023, 37(5), 1237-1251. DOI: https://dx.doi.org/10.4314/bcse.v37i5.15

Anti-site disorder, arising due to the similar size of Fe and Mo ions in Sr2FeMoO6 (SFMO) double perovskites, hampers spintronic applicability by deteriorating the magnetic response of this double perovskite system. A higher degree of anti-site disorder can also completely destroy the half-metallicity of the SFMO system. To study the effects of different process gas conditions on the anti-site disorder, we have prepared a series of SFMO thin films on SrTiO3 (001) single-crystal substrate using a pulsed laser deposition (PLD) technique. The films are grown either under vacuum or under N2/O2 partial gas pressures. The vacuum-grown SFMO film shows the maximum value of saturation magnetization (MS) and Curie temperature (TC), signaling the lowest anti-site disorder in this series. In other words, there is a long-range Fe/Mo-O-Mo/Fe ferrimagnetic exchange in the vacuum-grown thin film, thereby enhancing the magnetization. Further, all the SFMO films show a semiconducting state with a systematic increase in overall resistivity with the increased anti-site disorder. The electrical conduction mechanism is defined by the variable-range hopping model at low temperatures. Raman spectra show a weak Fano peak, suggesting the presence of electron–phonon coupling in SFMO thin films. These results show the significance of the process gas in causing anti-site disorder, tuning the degree of this disorder and therefore its influence on the structural, magnetic, electrical, and vibrational properties of SFMO thin films.

Gallium-doped ZnO (GZO) thin films on glass, which can be used as transparent electrodes, were prepared using a spin coating technique. Thermal analysis and Fourier-transform infrared spectroscopy of the dried precursor solution of Zn acetate and Ga nitrate dissolved in ethanol with diethanolamine confirmed the decomposition of the organic components upon heating and the formation of ZnO at 450 °C. The thin films fired at 600 °C in oxygen and air, and the films annealed at 400 °C in Ar/H2, were polycrystalline, 140 nm thick, and exhibited a homogeneous microstructure with 50 nm grains and a smooth surface, as shown by X-ray powder diffraction and scanning electron and atomic force microscopy. The sheet resistance Rs measured using the 4-probe technique showed a change in Rs within 80 days for all samples. The Rs of the GZO thin films annealed in oxygen and air with values of MΩ/sq decreased over time. Rs values of 150 kΩ/sq were obtained for GZO thin films annealed in Ar/H2, but the Rs increased over time. We suggest that the degradation of Rs is related to the adsorption of water on GZO and that the responses depend on the nature of the defects in the GZO lattice.

Composite electrolytes containing lithium ion conducting polymer matrix and ceramic filler are promising solid-state electrolytes for all solid-state lithium ion batteries due to their wide electrochemical stability window, high lithium ion conductivity and low electrode/electrolyte interfacial resistance. In this study, we report on the polymer infiltration of porous thin films of aluminum-doped cubic garnet fabricated via a combination of nebulized spray pyrolysis and spin coating with subsequent post annealing at 1173 K. This method offers a simple and easy route for the fabrication of a three-dimensional porous garnet network with a thickness in the range of 50 to 100 µm, which could be used as the ceramic backbone providing a continuous pathway for lithium ion transport in composite electrolytes. The porous microstructure of the fabricated thin films is confirmed via scanning electron microscopy. Ionic conductivity of the pristine films is determined via electrochemical impedance spectroscopy. We show that annealing times have a significant impact on the ionic conductivity of the films. The subsequent polymer infiltration of the porous garnet films shows a maximum ionic conductivity of 5.3 × 10-7 S cm-1 at 298 K, which is six orders of magnitude higher than the pristine porous garnet film., Deutsche Forschungsgemeinschaft

Currently, the presence of spurious microwave radiation is increasing in the environment, which has caused concern due to possible health problems in living beings and electromagnetic interference in electronic systems. To control this problem, studies in the materials area are taking place, aiming to attenuate the spurious radiation and meet requirements of good performance in broadband, low cost and low weight. The present work aimed to study Cu and Ni nanometric films with thicknesses of 65 and 200 nm, deposited on polyethylene terephthalate substrate by magnetron sputtering. Scanning electron microscopy with a field emission gun (FEG-SEM) showed that the films produced have different morphological textures, due to the parameters used in the sputtering process and also the free energy of metals. Impedance spectroscopy measurements showed that the films have low conductivity values, due to the metallic oxides formed on the film surfaces, confirmed by X-ray diffraction, and also to the presence of defects. Electromagnetic characterization (8.2 – 12.4 GHz) showed that the Cu and Ni thin films had low performance, except the Ni_200 nm film, which showed a total shielding efficiency of about 30% in broadband. This result is promising considering the nanometric thickness of the Ni film.

Bu çalışmada NiO ince filmleri, sol jel döndürme kaplama yöntemi farklı kaplama sayılarına göre n-Si alttaşlar üzerine büyütülerek heteroeklem uygulamaları gerçekleştirilmiştir. İnce film kalınlığının heteroeklem yapıların elektriksel ve optoelektriksel özelleri üzerindeki etkisi incelenmiştir. Heteroeklem yapıların seri direnç (Rs), düzeltme oranı (RR), idealite faktörü (n) ve bariyer yüksekliği (ΦB) gibi önemli bağlantı parametreleri I-V verileri analiz edilerek hesaplandı. Üretilen heteroeklem yapıların karanlık ve farklı aydınlatma şiddetleri altında akım-gerilim (I-V) karakteristikleri incelendi. Tüm yapıların ışığa duyarlı olduğu ve doğrultma davranışı sergilediği gösterildi. Diyotların idealite değerleri 3,29-7,05 arasında değişirken, bariyer yükseklikleri 0,67-0,76 arasında ve seri direnç değerleri 270-4436 arasında değişmiştir. Üretilen cihazların elektriksel davranışları farklı frekanslarda kapasite-gerilim (C-V), iletkenlik-gerilim (G-V) ve Seri direnç (Rs-V) ölçümleri ile incelenmiştir. Artan frekansla kapasitenin, iletkenliğin ve seri direncin sırasıyla azaldığı, arttığı ve arttığı belirlendi. Bu davranış, üretilen numunelerin arayüz durumlarının varlığından kaynaklanmaktadır. Elektriksel karakterizasyon sonuçları, üretilen tüm cihazların optoelektronik alanlarda optik sensörler veya fotodiyotlar olarak çalıştırılabileceğini göstermiştir., In this study, heterojunction structures were carried out by deposition of NiO thin films on n-Si substrates according to different coating times by sol gel spin coating method. The effect of thin film thickness on electrical and optoelectrical properties of heterojunction structures was investigated. The crucial electrical parameters such as series resistance (Rs), rectification ratio (RR), ideality factor (n) and barrier height (ΦB) of heterojunction structures were calculated by analyzing I-V data. The current-voltage (I-V) characteristics of the fabricated heterojunction structures were investigated under dark and different illumination intensities. All structures were shown to be photo sensitive and exhibit a rectification behavior. While the ideality values of the diodes varied between 3.29 and 7.05, the barrier heights varied between 0.67-0.76 and the series resistance values between 270-4436.

Metal-based catalysts are indispensable in modern chemistry and one of the biggest challenges for industrial applications is to quantify their performance and stability. The metrics of performance can be obtained in terms of the turnover number and turnover frequency, and the stability might be associated with the leaching of the heterogeneous catalysts. Thus, metal quantification is the starting point to understand and evaluate the features of catalysts. Among the technologies for metal determination, spectrophotometric analysis stands out for being cheap and easy to perform. However, the challenge is the sample preparation to direct quantification from the heterogeneous materials. Herein, it is shown how important is the photochemical pre-treatment for the quantification of the total iron from heterogeneous thin films composed of iron-based materials. The photochemical approach was used to ensure a full dissociation of iron ions before the quantification. This method was revealed to be highly effective and precise, having a wide range of applications for different iron-based catalysts.

The effects on the structure and magnetic properties of Eu1−xYxMnO3 (0.0 ≤ x ≤ 0.5) thin films due to lattice strain were investigated and compared with those obtained in equivalent composition ceramics. The films were deposited by spin-coating chemical solution onto PtTiO2SiO2Si (100) standard substrates. X-ray diffraction and Raman spectroscopy measurements revealed that all films crystallize in orthorhombic structure with space group Pnma, observing an added contraction of the unit cell with increasing Y-substitution ou Eu, corresponding to a broadening of the Mn-O1-Mn angle and a gradual decrease in magnetic order response.

Iron–cobalt (FeCo) alloys are highly desirable for their exceptional and adjustable physicochemical properties, particularly in the form of thin films. This study focuses on the growth of iron–cobalt (FeCo) alloy thin films using potentiostatic electrodeposition. The effects of applied voltage and FeCo stoichiometry on the morphology, structure, and magnetic properties of the films are investigated. The results indicate that the electrodeposition potential does not affect the overall stoichiometry or the structural and magnetic properties. However, it does impact film thickness and grain sizes. Higher applied potentials lead to thicker films with faster growth rates, as well as smoother and more homogeneous films with smaller grains. Films with different Fe:Co ratios (Fe90Co10, Fe50Co50, and Fe10Co90) are obtained, and their compositions have a direct impact on morphology, with the amount of Fe influencing film thickness, growth rates, and grain sizes. Increasing Fe content (50, 90%) leads to thicker films and smaller grains. Films with low Fe content (10%) exhibit a face-centered cubic (fcc) structural phase instead of the typical body-centered cubic (bcc) structure. All FeCo alloys display soft magnetic properties with characteristic coercivities, and the low Fe (10%) sample with the fcc structure exhibits the highest coercivity among all the samples. The nucleation and growth mechanisms are investigated using electrodeposition curves and the Scharifker and Hills model. Increasing the applied potential leads to thicker films and higher growth rates, with the nucleation mechanism identified as instantaneous nucleation in the diffusion-controlled regime.

A new technique for determining the point spread function, which is required for measuring the surface potential using Kelvin probe microscopy (KPM), is presented. The method involves using a silicon carbide substrate coated with single-layer and bilayer graphene as a test structure and obtaining KPM potential profiles in different directions on the surface. This makes it possible to determine the KPM point spread function, which can be used to perform deconvolution and accurately recover the surface potential.

In order to develop the methods of neutron and X-ray reflectometries for the study of surface layers of liquid systems, a method of increasing the sensitivity of the reflectometric experiment to the appearance and evolution of near-surface layers is proposed. Therefore, Ni/Ti multilayered heterostructures are tested regarding for the practical applicability of the quasi-homogeneous approach with varying effective scattering length density of thin (thickness, З метою розвитку методiв нейтронної та рентґенiвської рефлектометрiї для дослiдження поверхневих шарiв рiдинних систем запропоновано метод збiльшення чутливостi рефлектометричного експерименту до появи та еволюцiї приповерхневих шарiв. У зв’язку з цим, проведено тестування багатошарових гетероструктур Ni/Ti щодо практичного застосування квазиоднорiдного пiдходу зi змiною ефективної густини довжини розсiяння рентґенiвського випромiнювання тонких (товщиною до 100 нм) металевих плiвок в рентґенiвських рефлектометричних експериментах на прикладi електрохiмiчних iнтерфейсiв. Структури з надзвичайно малою товщиною двошарової системи Ni/Ti та рiзним спiввiдношенням товщин пiдшарiв нiкелю та титану були синтезованi методом магнетронного напилення. Проаналiзовано дзеркальну вiдбивну здатнiсть рентґенiвського випромiнювання вiд поверхнi гетероструктур для визначення межi можливостi використання квазиоднорiдного наближення.

The methods of Raman spectroscopy, scanning electron microscopy, atomic force microscopy, and X-ray fluorescence microanalysis are used to study the influence of tin on the shape and sizes of micro- and nano-structures arising on the surface of layered Si–Sn–Si films, as well as on the formation of Si nanocrystals in them during the tin-induced crystallization of amorphous silicon. In this work, the problems dealing with the experimental evaluation of the formation efficiency of Si nanocrystals in Si–Sn–Si films, the determination of the forms and scales of the film surface roughness, and the micro-distribution of impurities over the film surface and across the film thickness are tackled. The possibility of the formation of Si nanocrystals a few nanometers in size over most of the Si–Sn–Si film volume is experimentally confirmed. It is established for the first time that, during the production of such films using the thermal vacuum sputtering method, the thickness of a tin layer and its ratio to the thickness of silicon layers determine the shape and scale of the periodic surface relief structuring, which is important for the production of electronic devices. Quasi-spherical formations from 20 nm to 2–3 μm in diameter turned out to be the main element of the film surface relief structuring. The surface roughness induced by them can vary from a few nanometers to several tens of nanometers, depending on the layer deposition conditions. The shape of surface formations can change from cluster-like dendrites of the fractal type to convex ellipsoids and polygons. It is shown that the primary structuring occurs as the formation of a layer of hemispherical tin microdroplets already in the course of tin deposition. The secondary structuring occurs at the stage, when the second layer of silicon is deposited onto the layer of tin hemispheres. At this stage, a layer of the amorphous semiconductor is formed on the surface of the liquid metal, and this phenomenon is studied for the first time. The so-obtained amorphous silicon has a porous structure and consists of cluster-like dendrites of the fractal type about hundreds of nanometers in scale. The smallest dendrite elements also have a quasi-spherical shape 20–50 nm in diameter. Possible applications of the obtained results are discussed., Методи Раманiвської спектроскопiї, растрової електронної мiкроскопiї, атомно-силової мiкроскопiї i рентґено-флуоресцентного мiкроаналiзу застосованi з метою дослiдження впливу олова на форму i розмiри мiкро- та наноструктури поверхнi шаруватих плiвок Si–Sn–Si, а також на утворення в них нанокристалiв Si пiд час iндукованої оловом кристалiзацiї аморфного кремнiю. В данiй роботi вирiшувалися задачi експериментальної оцiнки ефективностi формування нанокристалiв Si в плiвках Si–Sn–Si, а також визначення форм i масштабiв шорсткостi поверхнi плiвок, мiкророзподiлу домiшок по їх площi i перерiзу. Експериментально пiдтверджено можливiсть формування нанокристалiв Si масштабу одиниць нанометрiв в бiльшiй частинi об’єму плiвок Si–Sn–Si. Вперше встановлено, що при виготовленнi таких плiвок методом термiчного вакуумного напилення товщина шару олова та її спiввiдношення з шарами кремнiю визначають форму i масштаб перiодичної структуризацiї рельєфу поверхнi, яка важлива для виготовлення реальних електронних приладiв. Головним елементом структурування рельєфу поверхнi плiвок виявилися квазисферичнi утворення дiаметром вiд 20 нм до 2–3 мкм. Зумовлена ними шорсткiсть поверхнi змiнюється в дiапазонi вiд одиниць до кiлькох десяткiв нанометрiв залежно вiд умов осадження шарiв. Форма поверхневих утворень змiнюється вiд гроно-подiбних дендритiв фрактального типу до опуклих елiпсоїдiв i багатокутникiв. Показано, що первинне структурування вiдбувається у виглядi утворення шару пiвсферичних мiкрокрапель олова вже у процесi його осадження. Вторинне структурування вiдбувається на етапi осадження другого шару кремнiю на шар олов’яних пiвсфер. На цьому етапi вiдбувається формування шару аморфного напiвпровiдника на поверхнi рiдинного металу, що дослiджувалось вперше. Отриманий таким чином аморфний кремнiй має порувату структуру, що складається з гроно-подiбних дендритiв фрактального типу масштабу сотень нанометрiв. Найменшi елементи дендритiв теж мають квазисферичну форму дiаметром 20–50 нм. Отриманi результати обговоренi з точки зору можливих застосувань.

We present the design, simulation, and characterization of a magnetic shape-memory alloy (MSMA) film actuator that transitions from bistable switching to resonant self-actuation when subjected to a stationary heat source. The actuator design comprises two Ni-Mn-Ga films of 10 µm thickness integrated at the front on either side of an elastic cantilever that moves freely between two heatable miniature permanent magnets and, thus, forms a bistable microswitch. Switching between the two states is induced by selectively heating the MSMA films above their Curie temperature Tc. When continuously heating the permanent magnets above Tc, the MSMA film actuator exhibits an oscillatory motion in between the magnets with large oscillation stroke in the frequency range of 50–60 Hz due to resonant self-actuation. A lumped-element model (LEM) is introduced to describe the coupled thermo-magnetic and magneto-mechanical performance of the actuator. We demonstrate that this performance can be used for the thermomagnetic energy generation of low-grade waste heat (T < 150 °C) with a high power output per footprint in the order of 2.3 µW/cm2.

ispartof: ADVANCED ENERGY MATERIALS status: Published online

Multicomponent equimolar perovskite oxides (ME-POs) have recently emerged as a highly promising class of materials with unique synergistic effects, making them well-suited for applications in such areas as photovoltaics and micro- and nanoelectronics. High-entropy perovskite oxide thin film in the (Gd0.2Nd0.2La0.2Sm0.2Y0.2)CoO3 (RECO, where RE = Gd0.2Nd0.2La0.2Sm0.2Y0.2, C = Co, and O = O3) system was synthesized via pulsed laser deposition. The crystalline growth in an amorphous fused quartz substrate and single-phase composition of the synthesized film was confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Surface conductivity and activation energy were determined using a novel technique implementing atomic force microscopy (AFM) in combination with current mapping. The optoelectronic properties of the deposited RECO thin film were characterized using UV/VIS spectroscopy. The energy gap and nature of optical transitions were calculated using the Inverse Logarithmic Derivative (ILD) and four-point resistance method, suggesting direct allowed transitions with altered dispersions. The narrow energy gap of RECO, along with its relatively high absorption properties in the visible spectrum, positions it as a promising candidate for further exploration in the domains of low-energy infrared optics and electrocatalysis.

Plasma-enhanced atomic layer deposition was employed to grow aluminum nitride (AlN) thin films on Si (100), Si (111), and c-plane sapphire substrates at 250 °C. Trimethylaluminum and Ar/N2/H2 plasma were utilized as Al and N precursors, respectively. The properties of AlN thin films grown on various substrates were comparatively analyzed. The investigation revealed that the as-grown AlN thin films exhibit a hexagonal wurtzite structure with preferred c-axis orientation and were polycrystalline, regardless of the substrates. The sharp AlN/substrate interfaces of the as-grown AlN are indicated by the clearly resolved Kiessig fringes measured through X-ray reflectivity. The surface morphology analysis indicated that the AlN grown on sapphire displays the largest crystal grain size and surface roughness value. Additionally, AlN/Si (100) shows the highest refractive index at a wavelength of 532 nm. Compared to AlN/sapphire, AlN/Si has a lower wavelength with an extinction coefficient of zero, indicating that AlN/Si has higher transmittance in the visible range. Overall, the study offers valuable insights into the properties of AlN thin films and their potential applications in optoelectronic devices, and provides a new technical idea for realizing high-quality AlN thin films with sharp AlN/substrate interfaces and smooth surfaces.

We performed the experimental and theoretical study of the heating and damaging of ruthenium thin films induced by femtosecond laser irradiation. Results of an optical pump-probe thermoreflectance experiment with rotating sample allowing to significantly reduce heat accumulation in irradiated spot are presented. We show the evolution of surface morphology from growth of a heat-induced oxide layer at low and intermediate laser fluences to cracking and grooving at high fluences. Theoretical analysis of pump-probe signal allows us to relate behavior of hot electrons in ruthenium to the Fermi smearing mechanism. The analysis of heating is performed with the two-temperature modeling and molecular dynamics simulation, results of which demonstrate that the calculated melting threshold is higher than experimental damage threshold. We attribute it to heat-induced surface stresses leading to cracking which accumulates to more severe damage morphology. Our results provide an upper limit for operational conditions for ruthenium optics and also direct to further studies of the Fermi smearing mechanism in other transition metals., 23 pages, 11 figures, 1 table, 7 data files in supplementary material

In the last decade, metal-graphene composites have seen significant progress and have received increasing attention because of graphene's ability to improve the mechanical properties. The main mechanism of improvement in metal graphene composite is based on the impeding of dislocations by graphene sheets. The work includes studying the mechanisms behind the improvement caused by graphene sheets and particles using Molecular Dynamics and Density Functional Theory. Interatomic potentials that play an important role in determining the accuracy of Molecular dynamics simulations are developed for Cu-C, Ni-C, Ti-C, and Ni-Ti-C systems. Nanolayered metal-graphene composites are fabricated and the effect of graphene particles on crack's path are investigated by electron microscopy. The mechanisms behind crack's behavior is investigated by atomistic simulations and by comparing energy release rates. Metallic systems that do not deform by dislocations like metallic glasses, NiTi etc. are reinforced with graphene and are also examined by atomistic simulations. In addition, a novel metal-graphene composite in which the metal matrix undergoes a uniform large recoverable phase transformation when subjected to mechanical loading is proposed and investigated using atomistic simulations. The material has the potential to overcome the long-standing challenge of transferring the extraordinary mechanical performance of nanoscale materials to the bulk level. Doctor of Philosophy In the last decade, metal-graphene composites have seen significant progress and have received increasing attention because of graphene's ability to improve the mechanical properties. The main mechanism of improvement in metal graphene composite is based on the impeding of dislocations by graphene sheets. The work includes studying the mechanisms behind the improvement caused by graphene sheets and particles by studying the interaction of metal and Carbon atoms in graphene. Functions that simulate these interactions play important role in determining the accuracy simulations. These functions are developed for Cu-C, Ni-C, Ti-C, and Ni-Ti-C systems. Nanolayered metal-graphene composites are fabricated and the effect of graphene particles on crack's path are investigated by electron microscopy. The mechanisms behind crack's behavior is investigated by atomistic simulations and by comparing energy release rates. Metallic systems that do not deform by dislocations like metallic glasses, NiTi etc. are reinforced with graphene and are also examined by atomistic simulations. In addition, a novel Graphene-Metal composite in which the metal matrix undergoes a uniform large recoverable phase transformation when subjected to mechanical loading is proposed and investigated using atomistic simulations. The material has the potential to overcome the long-standing challenge of transferring the extraordinary mechanical performance of nanoscale materials to the bulk level.

Chalcogenides semiconductors are currently being studied as active layers in the development of electronic devices in the field of applied technology. In the present paper, cadmium sulfide (CdS) thin films containing nanoparticles of the same material as the active layer were produced and analyzed for their application in fabricating optoelectronic devices. CdS thin films and CdS nanoparticles were obtained via soft chemistry at low temperatures. The CdS thin film was deposited via chemical bath deposition (CBD); the CdS nanoparticles were synthesized via the precipitation method. The construction of a homojunction was completed by incorporating CdS nanoparticles on CdS thin films deposited via CBD. CdS nanoparticles were deposited using the spin coating technique, and the effect of thermal annealing on the deposited films was investigated. In the modified thin films with nanoparticles, a transmittance of about 70% and a band gap between 2.12 eV and 2.35 eV were obtained. The two characteristic phonons of the CdS were observed via Raman spectroscopy, and the CdS thin films/CdS nanoparticles showed a hexagonal and cubic crystalline structure with average crystallite size of 21.3–28.4 nm, where hexagonal is the most stable for optoelectronic applications, with roughness less than 5 nm, indicating that CdS is relatively smooth, uniform and highly compact. In addition, the characteristic curves of current-voltage for as-deposited and annealed thin films showed that the metal-CdS with the CdS nanoparticle interface exhibits ohmic behavior.

Thin-film solid-state batteries have been studied since the 1950s, but it was the demonstration of remarkable cycling stability in an all-thin-film Li/LiPON (lithium phosphorus oxynitride)/LCO (LiCoO2) cell in the mid-1990s that captured the attention of the solid-state battery research community. Although these cells were commercialized on a small scale, their utility is limited by their low areal capacities. Nevertheless, there is a growing realization that thin-film processing techniques such as RF (radio frequency) magnetron sputtering offer various advantages over the traditional powder processing routes commonly used to fabricate solid-state cell components. The first investigation reported here looked at a strategy to improve the performance of the “traditional” all-thin-film cell by optimizing the processing of the LCO cathode. Most previous studies on thin-film LCO cathodes have reported similar processing conditions, and these are not optimal for large-scale manufacturing. In this work, the process pressure used for RF magnetron sputtering was reduced while the power density was increased relative to typical conditions from the literature. Several other changes were made, including the omission of an oxygen gas flow during deposition, until ~3 μm thick films well-crystallized in the targeted HT-LCO (high temperature LCO) structure were achieved at a deposition rate 3-4 times higher than obtained using the reference conditions. Characterization by X-ray diffraction (XRD) revealed strong parallel alignment of the (104), (101) and (110) planes with the film surface, as desired for efficient lithium transfer to the electrolyte. Notably, a maximum areal discharge capacity of 172 μAh cm-2 was measured during galvanostatic cycling between 3.0 and 4.3 V at a current density of 18 μA cm-2, which is one of the highest values reported. This can be attributed to the greater film thicknesses reported here compared to those of most previous studies (generally below 1 μm) and the use of processing conditions optimized both for manufacturability and electrochemical performance. The second investigation looked at the synthesis of Li3OCl, a member of the recently discovered class of lithium-rich antiperovskite electrolyte materials. This compound has attracted interest because of its predicted stability in contact with lithium metal anodes, raising the prospect of future application in all-solid-state lithium metal batteries. However, its thermodynamic instability at room temperature and extreme hygroscopicity appear to preclude synthesis by traditional solid state and melt processing routes since the more stable Li2OHCl compound is likely to form instead. This work attempted to synthesize Li3OCl using RF magnetron sputtering, taking advantage of the moisture-free environment and high cooling rates associated with this technique. Sputtering was performed from an equimolar powdered mixture of the precursor compounds Li2O and LiCl. After optimizing the sputtering conditions for target stability, XRD, Fourier transform infrared spectroscopy and electrochemical impedance spectroscopy were used to show that a small volume fraction of a phase with the properties expected for Li3OCl was present in the as-deposited films. The results were compared to those of films deposited from Li2OHCl powder to prove that Li2OHCl had not been produced inadvertently. Both sets of films exhibited low ionic conductivities (on the order of 10-8 S cm-1) owing to their low antiperovskite phase purities. Nevertheless, an increased understanding of the processing-structure-properties relationships pertaining to these compounds allowed several promising directions for future research to be proposed.

Polyelectrolyte multilayers are nanofilms with vast applications in numerous areas such as medicine and food industry. Recently, they have been getting a lot of attention as potential food coatings for the prevention of fruit decay during transportation and storage, and therefore the coatings need to be biocompatible. In this study, we fabricated thin films made of biocompatible polyelectrolytes, positively charged polysaccharide chitosan, and negatively charged carboxymethyl cellulose on a model silica surface. Typically, to enhance the properties of the prepared nanofilms, the first layer (precursor layer) of poly(ethyleneimine) is used. However, for the construction of completely biocompatible coatings, this could be problematic due to potential toxicity. This study offers an option for a viable candidate as a replacement precursor layer: chitosan itself was adsorbed from a more concentrated solution. In the case of chitosan/carboxymethyl cellulose films, using chitosan over poly(ethyleneimine) as a precursor layer has shown a twofold increase in film thickness, as well as an increase in film roughness. In addition, these properties can be tuned by the presence of a biocompatible background salt (e.g., sodium chloride) in the deposition solution that has proven to change the film thickness and surface roughness depending on the salt concentration. Such a straightforward way of tuning the properties of these films combined with their biocompatibility makes this precursor material a prime candidate for use as a potential food coating.

Atomic layer deposition (ALD) is a useful tool for producing ultrathin films and coatings of complex composition with high thickness control for a wide range of applications. In this study, the growth of zinc–titanium oxide nanofilms was investigated. Diethyl zinc, titanium tetrachloride, and water were used as precursors. The supercycle approach was used, and wide ZnO/TiO2 (ZTO) ALD cycles were prepared: 5/1, 3/1, 2/1, 1/1, 1/2, 1/3, 1/5, 1/10, 1/20. Spectral ellipsometry, X-ray reflectometry, X-ray diffraction, scanning electron microscopy, SEM-EDX, and contact angle measurements were used to characterize the thickness, morphology, and composition of the films. The results show that the thicknesses of the coatings differ considerably from those calculated using the rule of mixtures. At high ZnO/TiO2 ratios, the thickness is much lower than expected and with increasing titanium oxide content the thickness increases significantly. The surface of the ZTO samples contains a significant amount of chlorine in the form of zinc chloride and an excessive amount of titanium. The evaluation of the antibacterial properties showed significant activity of the ZTO–1/1 sample against antibiotic-resistant strains and no negative effect on the morphology and adhesion of human mesenchymal stem cells. These results suggest that by tuning the surface composition of ALD-derived ZTO samples, it may be possible to obtain a multi-functional material for use in medical applications.

Vodikov peroksid je snov, katere uporaba je v zadnjih desetletjih v velikem porastu v različnih industrijah in širokem spektru dejavnosti, obenem pa je njena proizvodnja cenovno in energijsko potratna. Zato se že nekaj časa išče okolju prijazen način pridobivanja te spojine, ki bi ublažil že tako obremenjen vpliv na okolje. Rešitev bi lahko bila elektrokemijska sinteza, problem pa se pojavi pri elektrokatalizatorju, ki mora biti dovolj aktiven, selektiven in stabilen. Ob pomoči predhodnih raziskav smo sintetizirali elektrokatalizator na osnovi niklja na substratu reduciranega grafen oksida dopiranega z dušikom ter ga temeljito okarakterizirali. Elektrokatalizator ima v alkalnem mediju pri nizkih potencialih dobro aktivnosti in selektivnost ter odlično stabilnost. Sinteza elektrokatalizatorja je precej preprosta ter relativno hitra in poceni. Elektrokatalizator sem dispergiral v dveh različnih topilih in ga v obliki tankih filmov nanesel na tri različne substrate ter preveril njegove elektrokemijske lastnosti. Kot topili sem uporabil N,N-dimetilformamid ter mešanico demineralizirane vode, izopropanola in Nafiona. Elektrokatalizator dispergiran v DMF je na vseh substratih dal najbolj homogene filme, kar smo pokazali z vrstično elektronsko mikroskopijo. Filme sem nanesel na LTCC, nerjavno jeklo ter papir iz ogljikovih vlaken. Najboljše elektrokemijske rezultate je izkazal katalizator nanešen na CFP, kjer je bila v šaržnem elektrokemijskem reaktorju izmerjena gostota toka več kot desetkrat višja kot pri ostalih substratih. Taki filmi se bodo v prihodnosti uporabljali pri elektrosintezi vodikovega peroksida v pretočnih sistemih. Hydrogen peroxide is a compound whose use has been increasing dramatically in recent decades in a wide range of industries and activities, but its production is both costly and energy-intensive. For this reason, an environmentally friendly way of producing this compound has been sought for some time to mitigate its already high environmental impact. The solution could be electrochemical synthesis, but the problem arises with the electrocatalyst, which must be sufficiently active, selective and stable. With the help of preliminary research, we have synthesized and thoroughly characterised a nickel-based electrocatalyst on a nitrogen-doped reduced graphene oxide substrate.. The electrocatalyst exhibits good activity and selectivity and excellent stability in alkaline media at low potentials. The synthesis of the electrocatalyst is quite simple and relatively fast and inexpensive. I dispersed the electrocatalyst in two different solvents and deposited it as thin films on three different substrates and analysed its electrochemical properties. I used N,N-dimethylformamide and a mixture of demineralized water, isopropanol and Nafion as solvents. The electrocatalyst dispersed in DMF performed better on all substrates. Films were deposited on LTCC, stainless steel and carbon fiber paper. By far the best results were obtained on CFP, where the measured current density was more than ten times higher compared to the other two substrates. Such films will be used in the future for the electrosynthesis of hydrogen peroxide flow systems.

The composite polymer electrolytes (1-x)CsH2PO4-xF-2M (x = 0–0.3) have been first synthesized and their electrotransport, structural, and mechanical properties were investigated in detail by impedance, FTIR spectroscopy, electron microscopy, and X-ray diffraction methods. The structure of CsH2PO4 (P21/m) with salt dispersion is retained in the polymer electrolytes. The FTIR and PXRD data are consistent, showing no chemical interaction between the components in the polymer systems, but the salt dispersion is due to a weak interface interaction. The close to uniform distribution of the particles and their agglomerates is observed. The obtained polymer composites are suitable for making thin highly conductive films (60–100 μm) with high mechanical strength. The proton conductivity of the polymer membranes up to x = 0.05–0.1 is close to the pure salt. The further polymers addition up to x = 0.25 results in a significant decrease in the superproton conductivity due to the percolation effect. Despite a decrease, the conductivity values at 180–250 °C remain high enough to enable the use of (1-x)CsH2PO4-xF-2M as a proton membrane in the intermediate temperature range.

Lithium fluoride (LiF) crystals and thin films are utilized as radiation detectors for energy diagnostics of proton beams. This is achieved by analyzing the Bragg curves in LiF obtained by imaging the radiophotoluminescence of color centers created by protons. In LiF crystals, the Bragg peak depth increases superlinearly with the particle energy. A previous study has shown that, when 35 MeV protons impinge at grazing incidence onto LiF films deposited on Si(100) substrates, the Bragg peak in the films is located at the depth where it would be found in Si rather than in LiF due to multiple Coulomb scattering. In this paper, Monte Carlo simulations of proton irradiations in the 1–8 MeV energy range are performed and compared to experimental Bragg curves in optically transparent LiF films on Si(100) substrates. Our study focuses on this energy range because, as energy increases, the Bragg peak gradually shifts from the depth in LiF to that in Si. The impact of grazing incidence angle, LiF packing density, and film thickness on shaping the Bragg curve in the film is examined. At energies higher than 8 MeV, all these quantities must be considered, although the effect of packing density plays a minor role.

The automotive industry is one of the largest industrial segments in the world market. The exhaust system of motor vehicles is responsible for the emission and treatment of toxic gasses released by the engine. In this sense, the application of titanium on an AISI 1020 steel substrate was carried out by plasma deposition using a cathode cage. The aim of this research was to evaluate the application of this material in the exhaust system of motor vehicles. The samples were characterized by scanning electron microscopy (SEM), confocal microscopy (CM), microhardness tests and corrosion resistance tests. The samples exhibited a thin film with higher titanium content and hardness than the uncoated sample. The corrosion potential also increased and the current density was lower than the uncoated sample. The conclusion is that the deposition of thin titanium films on AISI 1020 steel with CCPD has the potential to produce thin films.

In this study, we employed a polymer processing method based on solvent vapor annealing in a confined environment to swell-rich thin films of polybutadiene-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) triblock copolymers and to promote their crystallization. As revealed by optical and atomic force microscopy, thin films of triblock copolymers containing a rather short crystalline poly(ethylene oxide) block that was massively obstructed by the other two blocks were unable to crystallize following the spin-casting process, and their further swelling in solvent vapors was necessary in order to produce polymeric crystals displaying a dendritic morphology. In comparison, thin films of triblock copolymers containing a much longer poly(ethylene oxide) block that was less obstructed by the other two blocks were shown to crystallize into dendritic structures right after the spin-casting procedure, as well as upon rich swelling in solvent vapors.

This work presents a two-step procedure to obtain thin films with a combination of CuSbS2 and Cu12Sb4S13 phases for study in thermoelectric applications. The procedure consisted of the physical evaporation of sulfides layers (Sb2S3 and CuS) on glass substrates and the subsequent annealing of the samples in a N2 atmosphere. The characterizations by Raman spectroscopy and XRD revealed that the samples presented a varied percentage of Cu12Sb4S13 and CuSbS2. The results indicated that the percentage of phases depended on the initial thickness of the sulfide layers and the annealing temperature. The lower initial ratio between sulfide thicknesses and annealing temperature above 300 °C favored the formation of Cu12Sb4S13. However, the thermoelectric properties were improved when the phases coexisted in the thin film compared to samples with high percentages of Cu12Sb4S13. In this way, a sample with a power factor of 2.30 μW /cm∙ K2 at 60 ºC was identified.