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Due to their excellent hardness, transition metal nitrides have become a promising coating material for cutting tools and high-friction surfaces. The wear and corrosion protection offered by metal nitride hard coatings has paved the way for research on different combinations of metal nitrides. In this study, binary transition metal nitride coatings of CrMoN and CrTiN are deposited onto cutting tools and different substrates by co-sputtering of two metal targets simultaneously at an oblique angle by an ion-assisted DC magnetron sputtering process. The purpose of the deposition is to develop a uniform adhesive hard coating onto the specimens and to study their characteristics and performance. Both the hard adhesive coatings developed offer good surface morphologies which have been confirmed by AFM and FESEM, and their elemental composition is confirmed by XRD, XPS, and EDS characterizations. Hardness is measured by nanoindentation and also electrochemical studies for corrosion measurements are performed. In both the coatings, individual nitride phases have been formed in a mixed manner and have achieved a hardness value of about 13 GPa and the corrosion resistance of the coated specimen is found to be improved in comparison with the uncoated substrates. [ABSTRACT FROM AUTHOR]

In the study described herein, CrTaWNx thin films were deposited on Si and 304 stainless-steel (SUS304) substrates through magnetron co-sputtering using CrW and Ta targets. The nitrogen flow ratio (fN2 = [N2/(N2 + Ar)]) was adjusted to 0.05, 0.2, 0.4, and 0.5 to fabricate CrTaWNx films with various N contents. The CrTaWNx films prepared at a low fN2 of 0.05 exhibited a low stoichiometric ratio x of 0.16 and a nanocrystalline structure. In contrast, the CrTaWNx films fabricated at an fN2 of 0.2–0.5 exhibited x values of 0.42–0.62 and formed a face-centered cubic phase. The nanocrystalline (Cr0.34Ta0.20W0.46)N0.16 film exhibited mechanical properties and wear resistances that were inferior to those of the crystalline CrTaWNx thin films. A (Cr0.38Ta0.15W0.47)N0.55 film exhibited a hardness of 25.2 GPa, an elastic modulus of 289 GPa, and a low wear rate of 0.51 × 10−5 mm3/Nm. [ABSTRACT FROM AUTHOR]

Recently, the Internet of Things (IOT) has rapidly developed, leading to the development of many smart devices. Moreover, artificial intelligence (AI) and 5G communication are successful, and the demand for high-performance memory is increasing. The emerging nonvolatile RRAM has many advantages, such as low power consumption, fast operation speed, simple structure and excellent scalability, compared with traditional memories; this is promising for complex computing and mass storage. Zinc oxide (ZnO) is a promising candidate for transparent conducting oxide (TCO) applications because of its abundance, high conductivity, low toxicity, and cost-effectiveness. It is currently used in various optoelectronic components including thin-film transistors (TFTs) and photodetectors. Notably, TCO has been increasingly used in the switching layers of random resistive access memory systems. In this paper, we intend to combine AGO with a large energy gap and ZnO with a high conductivity to prepare AGZO as a switching layer for RRAM by co-sputtering. By adjusting the oxygen flow ratio and power of co-sputtering, the AGZO RRAM exhibited high performance with more than 1400 switching cycles, 102–103 on/off ratio, and low operation voltage, and high- and low-resistance states could be maintained for more than 10,000s. [ABSTRACT FROM AUTHOR]

The Ag-ZnO nanocomposite thin films of varying Ag contents were synthesized successfully using simultaneous RF- and DC-magnetron sputterings on quartz substrates. The as-prepared nanocomposites were then annealed in a mixture of hydrogen plus argon environment (95%Ar+5%H2) at a temperature of 300 °C. The pristine and annealed films were then subjected to synchrotron XRD to study for any possible structural modifications induced in the films. The crystalline behavior of the hexagonal wurtzite structure of ZnO, in the pristine and annealed samples of Ag-ZnO nanocomposites, was evident in samples prepared at low Ag content, but with increasing Ag content, the crystalline behavior of the hexagonal wurtzite structure was suppressed. FESEM utilized to study the formation of nanoparticles in the films revealed the non-uniform distribution and agglomeration of nanoparticles increases as the Ag content increases. A broad surface plasmon region in the range of 380–450 nm was observed for different compositions with remarkable blue and red shifts using UV-visible spectroscopy. These high-quality Ag-ZnO nanocomposite thin films with tunable optical properties were then used as surface-enhanced Raman spectroscopy (SERS) substrates for the detection of rhodamine B (RhB) at low concentrations of 10−6 M. The detection of RhB in trace amounts is important in the current scenario as wastewater discharge is a serious threat to our ecosystem. [ABSTRACT FROM AUTHOR]

(TiZrNbTa)Nx films were fabricated at various nitrogen flow ratios (RN2) through reactive direct current magnetron co-sputtering. The structural, mechanical, and anticorrosive properties of the (TiZrNbTa)Nx films were explored. The metallic TiZrNbTa film formed a body-centered cubic phase, and the film (N05) deposited at RN2 = 5% exhibited a nanocrystalline structure consisting of close-packed hexagonal and face-centered cubic (FCC) phases. In contrast, the films prepared at RN2 > 10% demonstrated an FCC phase. The N05 film has hardness and elastic modulus of 23.5 and 220 GPa, respectively, the highest hardness and relatively lower elastic modules among the studied nitride films. Moreover, the N05 film has the highest polarization resistance of 198 kΩ·cm2 measured by the potentiodynamic polarization method. The chemical states of the (TiZrNbTa)Nx films were examined by X-ray photoelectron spectroscopy.

Thin films of transition metal oxides and oxynitrides have proven highly effective in protecting stainless steels against corrosion in both chemically aggressive environments and biological fluids. In the present work, cerium zirconium oxynitride thin films were deposited to enhance the corrosion resistance of surgical-grade stainless steel to be used in osteosynthesis processes. Two techniques were employed: co-sputtering and radiofrequency (RF) sputtering, and the morphology and corrosion efficiency of the coatings deposited by each technique were evaluated. X-ray diffraction, X-ray photoelectron spectroscopy and field emission transmission electron microscopy were used to characterize the morphological and chemical structure, respectively. Additionally, the corrosion resistance of the oxynitride-coated surgical grade stainless steel system (ZrCeOxNy-AISI 316L) was assessed using Hank’s solution as the corrosive electrolyte, to determine its resistance to corrosion in biological media. The results show that ZrCeOxNy coatings increase the corrosion resistance of surgical grade stainless steel by two orders of magnitude and that the Ce(III)/Ce(IV) equilibrium decreases the corrosion rate, thereby increasing the durability of the steel in a biological environment. The results show that Ce coatings increase the corrosion resistance of surgical grade stainless steel by two orders of magnitude and that the Ce(III)/Ce(IV) equilibrium decreases the corrosion rate, thereby increasing the durability of the steel in a biological environment.

We fabricated aluminum-doped tantalum-oxide (Ta2O5:Al) thin films using a simple co-sputtering method and observed broad near-infrared (NIR) light emission with wavelengths around 700 to 1000 nm from a sample annealed at 900 °C without rare-earth elements. The NIR light emission is thought to be due to the superposition of three emission peaks around wavelengths of 800, 870, and 950 nm, and X-ray diffraction analyses revealed that the origin of the NIR light emission is related to AlTaO4 present in the Ta2O5:Al thin film.

A co-sputtering process for the deposition of Fe0.8Ga0.2B alloy magnetostrictive thin films is studied in this paper. The soft magnetic performance of Fe0.8Ga0.2B thin films is modulated by the direct-current (DC) sputtering power of an FeGa target and the radio-frequency (RF) sputtering power of a B target. Characterization results show that the prepared Fe0.8Ga0.2B films are amorphous with uniform thickness and low coercivity. With increasing FeGa DC sputtering power, coercivity raises, resulting from the enhancement of magnetism and grain growth. On the other hand, when the RF sputtering power of the B target increases, the coercivity decreases first and then increases because of the conversion of the films from a crystalline to an amorphous state. The lowest coercivity of 7.51 Oe is finally obtained with the sputtering power of 20 W for the FeGa target and 60 W for the B target. Potentially, this optimization provides a simple way for improving the magnetoelectric coefficient of magnetoelectric composite materials and the sensitivity of magnetoelectric sensors. [ABSTRACT FROM AUTHOR]

Fe 2-x Sn x O 3 structures grown by RF-DC magnetron co-sputtering. The band gap of Fe 2 O 3 , SnO 2 , Fe 2-x Sn x O 3 structure was calculated as 2.86, 4.06, 2.77 eV, respectively. The Fe 2 O 3 thin film has shown a tetragonal as well as the SnO 2 structure, however, the Fe 2-x Sn x O 3 (0 < x < 1) has shown rhombohedral structure. XPS measurements have shown change in binding energy which is due to the electron exchange of tin-iron with oxygen, and iron - tin oxide structure. This binding energy increases slightly with the chemical environment effect. The films were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM). In AFM images was seen that the iron oxide structure was pyramidal and the tin oxide structure was spherical, similar to the SEM image. The response of the film to hydrogen gas was measured at flow values of 100, 500 and 1000 ppm at 300 °C. Fe 2 O 3 thin films show 46%, SnO 2 61% and, Fe 2-x Sn x O 3 6.5% response to 1000 ppm H 2 gas. It is seen that the gas sensor response was affected by the morphological and structural features of the grown film. Current vs. time graph for thin films gas sensor. [Display omitted] • Thin films were successfully grown by RF-DC co-sputtering system. • Metal oxide hydrogen gas sensor devices were measured depending on different grown structures. • Fe 2 O 3 , SnO 2 , Fe 2-x Sn x O 3 thin films show 46%, 61%, 6.5% response to 1000 ppm H 2 gas. • Iron oxide and tin oxide have n-type carrier, while iron tin oxide has p-type carrier. [ABSTRACT FROM AUTHOR]

Several techniques have been developed to confer antibacterial properties to cotton textiles using silver nanoparticles. However, the antimicrobial performance of such a modified fabric can drastically decrease after a washing treatment. The aim of this work has been to develop antibacterial composite coatings with improved water resistance, deposited on cotton via the co-sputtering technique. The thin coatings, composed of a silica, alumina or zirconia matrix, with well embedded silver nanoclusters, were made to homogenously cover the cotton threads. The amount of silver was modulated, as was the power applied to the target, that is, 3 W for a lower amount and 5 W for a larger amount. The release of silver ions from the coatings into distilled water was very low, even after 14 days (less than 1 ppm) for all the coatings. The coated and uncoated cotton textiles were directly infected with the textile-colonizing pathogens Escherichia coli and Pseudomonas aeruginosa. After 24 h, a count of the colony forming units (CFU) revealed that the textiles coated with either the silver nanocluster/silica or zirconia matrix coatings were effective in preventing the adhesion and proliferation of E. coli bacteria, thereby preserving the textiles from contamination. However, P. aeruginosa was only absent in the case of the silica coatings or when the zirconia and alumina matrix coatings contained a large amount of silver. In all the considered cases, the CFU number was reduced with respect to the uncoated textiles. The durability of all the coatings was verified after ten washing cycles. Finally, coated textiles reported to be cytocompatible towards human fibroblasts and keratinocytes after simulating the release of toxic compounds or by directly seeding cells onto materials' surface. [ABSTRACT FROM AUTHOR]

CrWSiN films were prepared through the co-sputtering technique, and the process variables were substrate bias voltage and temperature. The mechanical properties of hardness and elastic modulus of the CrWSiN films were dominantly affected by their average crystallite size and by substrate bias voltage and temperature. Moreover, the effect of substrate temperature was more evident than that of substrate bias. The highest hardness and elastic modulus of 42.6 and 459 GPa, respectively, were obtained for the Cr20W28Si9N43 film fabricated at a substrate temperature of 400 °C, which exhibits an evident advantage over the 25.0 and 323 GPa values for the Cr21W28Si9N42 film fabricated at room temperature. In contrast, an increase in negative bias voltage to −100 V on the substrate decreased the mechanical properties compared to one prepared using a similar process without applying the negative bias voltage. The oxidation resistance of the Cr-enriched Cr37W4Si10N49 and Cr37W5Si10N48 films was superior to that of the Cr20W28Si9N43 films with near-equal Cr and W contents annealed at 900 °C in air. The formation of a surficial Cr2O3 layer plays a vital role in restricting subsequent oxidation for CrWSiN films. [ABSTRACT FROM AUTHOR]

Complex multilayer film structures were fabricated through a custom-built angular DC magnetron co-sputtering system. In this system, separate Cu, Al, and brass (Cu + Zn) targets were mounted on three magnetron guns, working in conjunction with a rotating substrate. This study aimed to compare the properties of films with intricate structures, which were sputtered onto glass slides and polypropylene substrates. The sputtering process was optimized using a Box–Behnken design, considering three variable operating conditions: substrate rotation speed, sputtering time, and sputtering voltage. The Analysis of Variance (ANOVA) results for film thickness and roughness, sputtered with three different materials onto glass slides and polypropylene (PP) substrates, indicated that all three independent variables significantly influenced the optimum response, with P-values less than 0.05 (

Ta doped TiN films were prepared on glass substrates by DC magnetron co-sputtering. The structure and properties of the obtained (Ti,Ta)N film were characterized by X-ray diffraction, Raman spectroscopy, ultraviolet/visible/near-infrared spectrophotometer and four probes method. The results show that with the increase of the sputtering power (PTa) for Ta target, the amount of Ta added to TiN lattice increases, resulting in a slight distortion of TiN lattice and stress transformation in the film. Correspondingly, the optical and electrical properties of the film changed. Raman spectrum was deconvoluted into five Lorentz peaks in the range of 50-1400 cm−1 and a new Raman peak appeared in all samples due to the substitution of Ta for Ti. The analysis of deconvolution results shows that the peak positions of different phonon modes and FWHM change, which may be related to the change of stress in the thin films caused by adding Ta to TiN lattice. The sample prepared with power of 50W has the maximum infrared emissivity of 1.35 and 0.43 at 2.5 and 25 μm wavelengths, respectively, indicating that (Ti,Ta)N film is promising candidate for replacing TiN in Low-E glass.

This study examined the palladium (Pd)-nickel (Ni) alloy films' ability to detect hydrogen (H 2) at various Ni concentrations. The co-sputtering method was used to make the Pd–Ni alloy sensors. The response of the Pd–Ni alloys sensor reduced linearly as Ni 8% concentration was added to Pd, and the resistance of the Pd–Ni alloys was reversible upon exposure to H 2 gas with absorption and desorption characteristics. The experimental findings demonstrated that the Pd–Ni alloy sensor response time of 11 s was much faster than that of pure Pd, with great selectivity and stability for a period of 90 days. • A sensor with high selectivity and response time towards hydrogen is reported. • Pd–Ni alloy (8%) show high response time compare to reference. • The sensor show stable reversible adsorption/desorption characteristics at RT. • Sensor show solid robust long term stability over two months. [ABSTRACT FROM AUTHOR]

Sb2Se3 has great potential for applications in near‐infrared sensors because of its narrow bandgap, environmental friendliness, and high absorption coefficient. However, the low conductivity of Sb2Se3 is an obstacle to the further development of high‐performance optoelectronic devices. In this study, to address this challenge, the selenization process is adopted. The incorporation of Se atoms into Sb2Se3 facilitates the crystallization of the films and the formation of [hk0]‐textured grains at a lower temperature than unselenized Sb2Se3. The selenized films possess larger grains than the unselenized ones at the same temperature. X‐ray photoelectron spectroscopy (XPS) results show that annealing causes the generation of donor‐like point defects (e.g., Vse and SbSe) and SeO2. The 250 °C‐annealed selenized Sb2Se3‐based photodetectors (PDs) have a high responsivity of 1130 mW A−1 and a specific detectivity of 4.62 × 1011 Jones. The PDs exhibit a fast response time (i.e., rise/fall time of 4.54 ms/8.50 ms), sensitivity of 94.2 at 20 mW cm−2, and external quantum efficiency of 155% at 200 µW cm−2. Further, the selenized PDs have good stability to moisture and air. Based on the XPS, X‐ray diffraction, and transmission electron microscope results, the improved performance of the selenized Sb2Se3‐based PDs is described and discussed. [ABSTRACT FROM AUTHOR]

Improvement in crystallinity was investigated by compensating for stoichiometric deviations of non-selenization processed Cu0.9In0.7Ga0.3Se2 (CIGS) thin films due to highly volatile Se by co-sputtering them with Te followed by rapid thermal annealing. The prepared CIGS:Te thin films did not show any linear correlation between the compositional ratio and the co-sputtering time of Te; however, the deviation parameter (Δs) from the stoichiometry and normalized stoichiometric deviations of Se + Te and In + Ga were largely consistent with the behavior of thin-film properties. The proposed method provides better crystallinity with a large grain size, clear grain boundaries, and low microstrain and dislocation density, resulting in a large volume of the unit cell. The CIGS:Te thin films used as absorbers show improved optical properties compared to the conventional CIGS thin films, with Eg = 1.548 eV. These results can advance the low-cost commercialization of the enhanced-efficiency CIGS:Te thin films without the selenization process. [ABSTRACT FROM AUTHOR]

Heterojunction structures of n-ZnO/p-Si were prepared through the growth of undoped ZnO and (Gd, Al) co-doped ZnO films onto p-type Si (1 0 0) substrates, using a co-sputtering method. The structural and optical properties of the Gd-doped ZnO films were studied as a function of different Al doping concentrations. The X-ray diffraction profiles indicated that the films had a nanocrystalline structure of ZnO with a (0 0 2) preferential orientation. An increase in the Al doping concentration deteriorated the (0 0 2) diffraction peak intensity. The transmittance measurements in the UV–Vis wavelength range indicated that the film's optical gap increased with increase in Al doping concentration. The heterojunction parameters were evaluated using the current–voltage (I-V) characterization carried out of the fabricated n-ZnO/p-Si heterostructure, in dark conditions at room temperature. From these measurements, the n-ZnO-based DMS/p-Si heterojunction diode with the use of (Gd, Al) co-doped ZnO film showed the lowest leakage current of 1.28 × 10−8 A and an ideality factor η of 1.11, close to the ideal diode behavior of  η  = 1, compared to the n-Gd-doped ZnO/p-Si and n-undoped ZnO/p-Si heterojunction diodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ag-doped CZTS improved V oc and J sc of CZTS solar cell. • The Ag-doping improved the grain growth, lowered porosity and well known CZTS antisite defects (e.g. Cu Zn and Zn Cu), which led to increase in V oc. • Ag-doping improved the grain size compared to than those for bare CZTS. • Capacitance-Voltage measurement indicated reduced recombination in the bulk of the Ag-doped CZTS absorber. • Ag-doped CZTS cells exhibited lower series resistance and higher J sc due to the suppression MoS 2 formation at the CZTS/Mo interface. We report an improvement in Cu 2 ZnSnS 4 (CZTS) solar cell efficiency with Ag-doping. The highest efficiency obtained for the fabricated CZTS solar cells was 5.84% and that for Ag-doped (ACZTS) cell efficiency was 6.66% without anti-reflection coating. The precursor film was prepared by co-sputtering of copper, tin sulfide (SnS), and zinc sulfide (ZnS) targets on a molybdenum (Mo) coated glass substrate. For the ACZTS, a thin layer of Ag (∼5 nm) was thermally evaporated on top of the CZTS precursor before annealing in an H 2 S/N 2 environment for crystallization. X-ray diffraction (XRD) patterns of both films showed Kesterite phase. Scanning electron microscopy (SEM) imaging showed that Ag-doping increased grain size and lowered porosity. Energy-dispersive X-ray spectroscopy (EDS) indicated that the ACZTS film was able to prevent some Sn loss compared to bare CZTS. Current Density – Voltage (J-V) measurements showed an improved efficiency for ACZTS was mostly due to increase in short-circuit current density (J sc), while open circuit voltage (V oc) improved slightly. The solar cell device with Ag-doping also exhibited lower series resistance and higher shunt resistance (R sh). The lower series resistance is attributed to the suppression of MoS 2 formation for ACZTS film, which was confirmed by Raman spectra. The optical band gaps for both CZTS and ACZTS films were measured to be 1.525 eV. Capacitance-Voltage (C-V) measurement showed that built-in voltage (V bi) for CZTS and ACZTS were 0.75 V and 0.70 V, respectively. The V oc of the ACZTS solar cell being closer to the built-in voltage indicated reduction in defects after Ag-doping. [ABSTRACT FROM AUTHOR]

This study demonstrated a silver (Ag) and samarium-doped ceria (SDC) mixed ceramic and metal composite (i.e., cermet) as a cathode for low-temperature solid oxide fuel cells (LT-SOFCs). Introducing the Ag-SDC cermet cathode for LT-SOFCs revealed that the ratio between Ag and SDC, which is a crucial factor for catalytic reactions, can be tuned by the co-sputtering process, resulting in enhanced triple phase boundary (TPB) density in the nanostructure. Ag-SDC cermet not only successfully performed as a cathode to increase the performance of LT-SOFCs by decreasing polarization resistance but also exceeded the catalytic activity of platinum (Pt) due to the improved oxygen reduction reaction (ORR). It was also found that less than half of Ag content was effective to increase TPB density, preventing oxidation of the Ag surface as well. [ABSTRACT FROM AUTHOR]

In this paper, we report on enhancing the biocompatibility properties of Hydroxyapatite-Titanium (HA-Ti) thin films fabricated using the co-sputtering method. By adjusting the HA/Ti ratio through varying the sputtering power of Ti, we obtained HA-Ti thin films with different crystal structures, morphologies, and hydrophilic properties. HA-Ti thin films sputtered at different titanium powers of 80, 100, 120, 140, and 160 W will obtain thin films with larger grain sizes and poorer crystallinity, respectively. However, their hydrophilic properties increase as the contact angle decreases from 78° to 20° degrees. In vitro BHK cell tests indicated that the HA-Ti thin film had excellent biocompatibility. Therefore, this material is suitable for biological applications and has significant potential in medical implant technology.

Abstract Due to their outstanding power density, long cycle life and low cost, supercapacitors have gained much interest. As for supercapacitor electrodes, molybdenum nitrides show promising potential. Molybdenum nitrides, however, are mainly prepared as nanopowders via a chemical route and require binders for the manufacture of electrodes. Such electrodes can impair the performance of supercapacitors. Herein, binder-free chromium (Cr)-doped molybdenum nitride (Mo2N) TFEs having different Cr concentrations are prepared via a reactive co-sputtering technique. The Cr-doped Mo2N films prepared have a cubic phase structure of γ-Mo2N with a minor shift in the (111) plane. While un-doped Mo2N films exhibit a spherical morphology, Cr-doped Mo2N films demonstrate a clear pyramid-like surface morphology. The developed Cr-doped Mo2N films contain 0–7.9 at.% of Cr in Mo2N lattice. A supercapacitor using a Cr-doped Mo2N electrode having the highest concentration of Cr reveals maximum areal capacity of 2780 mC/cm2, which is much higher than that of an un-doped Mo2N electrode (110 mC/cm2). Furthermore, the Cr-doped Mo2N electrode demonstrates excellent cycling stability, achieving ~ 94.6% capacity retention for about 2000 cycles. The reactive co-sputtering proves to be a suitable technique for fabrication of binder-free TFEs for high-performance energy storage device applications. Graphical Abstract

[Display omitted] • A metal–semiconductor-metal UV photodetector based on amorphous indium-tin-zinc-oxide (a-ITZO) was fabricated via co-sputtering. • The principle of persistent photoconductivity caused by oxygen vacancies in thin films is analyzed. • The photodetector's performances can be modulated by enhancing the oxygen ratio during co-sputtering. • This approach omitted annealing. • ITZO photodetector exhibits fast rise/decay time of 0.018/0.066 s. Enhancing the response speed of photodetectors is of great significance, for meeting the requirements of high-density optical arrays and integration. Wide bandgap indium oxide with high electron mobility makes it suitable for the preparation of high-speed response ultraviolet photodetectors. Nevertheless, oxide semiconductor is prone to form oxygen vacancies during the growth process, leading to persistent photoconductivity in photodetectors, which considerably limits the practical application in ultraviolet detection. In this work, a well-performing metal–semiconductor-metal structure ultraviolet photodetector based on amorphous indium-tin-zinc-oxide was fabricated via co-sputtering technique. By enhancing the oxygen ratio during the co-sputtering, the concentration of oxygen vacancies was effectively reduced, which modulated the performances of the photodetector. This approach not only shortened the photodetector's response time but also omitted the annealing step, enabling a room-temperature fabrication process. As a result, the optimized indium-tin-zinc-oxide photodetector of 30 % oxygen exhibited remarkably rapid response characteristics under 367 nm ultraviolet irradiation, with rise and decay times of 0.018 and 0.066 s, respectively. Simultaneously, the optimized indium-tin-zinc-oxide phototransistor exhibited exceptional performance metrics, including a high photoresponsivity of 480 A/W, a detectivity of 3.2 × 1012 Jones and an external quantum efficiency of 1336 % under 367 nm ultraviolet irradiation with 1 mW/cm2 light intensity. [ABSTRACT FROM AUTHOR]

[Display omitted] • HIPIMS – ECWR with Fe and Sn targets leads to Fe 2 O 3 :Sn films with good PEC photoresponse. • Processing parameters (power to Fe and Sn target) correlate with the Sn content in the film. • When ECWR is added, the processing pressure and time can be reduced leading to better crystallinity and PEC behaviour. • doping by Sn(Pt) diffusion from the FTO(Pt) substrate significantly improved photoresponse. Semiconducting Fe 2 O 3 thin films were deposited on SnO 2 :F (FTO) and Pt substrates by reactive high-power impulse magnetron sputtering combined with electron cyclotron wave resonance plasma (HiPIMS + ECWR). Fe 2 O 3 films were fabricated either by sputtering from a single Fe target or by co-sputtering from an additional Sn target. Plasma parameters during co-sputtering were measured by an RF probe system enabling the comparison between HiPIMS + ECWR and only HiPIMS conditions used for the film deposition. As deposited Fe 2 O 3 films were post-annealed in air at 450 °C and 650 °C, respectively. It was shown that as deposited Fe 2 O 3 films were amorphous but became crystalline after post-annealing at 450 °C. Further increase of annealing temperature to 650 °C did not improve significantly the crystalline structure of the Fe 2 O 3 film. All post-annealed Fe 2 O 3 films exhibited photocurrents in the anodic region; generally, hematite films annealed at 650 °C exhibited higher photocurrents than those annealed at 450 °C. Films doped by Sn co-sputtering had higher photocurrents than films only doped by Sn diffusion during post-annealing from the FTO substrate. Hematite films on Pt substrate doped by Sn co-sputtering and post-annealed at 650 °C exhibited the highest photocurrents. It was verified by XPS analysis with ion sputtering depth profiling that Pt atoms also diffuse from the Pt substrate into the Fe 2 O 3 film during the post-annealing at 650 °C and can, similar to Sn in the case of an FTO substrate, act as a dopant. [ABSTRACT FROM AUTHOR]

A co-sputtering process for the deposition of Fe0.8Ga0.2B alloy magnetostrictive thin films is studied in this paper. The soft magnetic performance of Fe0.8Ga0.2B thin films is modulated by the direct-current (DC) sputtering power of an FeGa target and the radio-frequency (RF) sputtering power of a B target. Characterization results show that the prepared Fe0.8Ga0.2B films are amorphous with uniform thickness and low coercivity. With increasing FeGa DC sputtering power, coercivity raises, resulting from the enhancement of magnetism and grain growth. On the other hand, when the RF sputtering power of the B target increases, the coercivity decreases first and then increases because of the conversion of the films from a crystalline to an amorphous state. The lowest coercivity of 7.51 Oe is finally obtained with the sputtering power of 20 W for the FeGa target and 60 W for the B target. Potentially, this optimization provides a simple way for improving the magnetoelectric coefficient of magnetoelectric composite materials and the sensitivity of magnetoelectric sensors.

This study explored the structural characteristics, mechanical properties, and oxidation behavior of W-enriched TaWSiN films prepared through co-sputtering. The atomic ratios [W/(W + Ta)] of the as-deposited films maintained a range of 0.77–0.81. The TaWSiN films with a Si content of 0–13 at.% were crystalline, whereas the film with 20 at.% Si was amorphous. The hardness and Young's modulus of crystalline TaWSiN films maintained high levels of 26.5–29.9 GPa and 286–381 GPa, respectively, whereas the hardness and Young's modulus of the amorphous Ta7W33Si20N40 films exhibited low levels of 18.2 and 229 GPa, respectively. The oxidation behavior of TaWSiN films was investigated after annealing at 600 °C in a 1%O2–Ar atmosphere, and cone-like Ta0.3W0.7O2.85 oxides formed and extruded from the TaWSiN films. [ABSTRACT FROM AUTHOR]

Aluminum nitride (AlN) is a semiconductor material possessing a hexagonal wurtzite crystal structure with a large band gap of 6.2 eV. AlN thin films have several potential applications and areas for study, particularly in optoelectronics. This research study focused on the preparation of Ni-doped AlN thin films by using DC and RF magnetron sputtering for optoelectronic applications. Additionally, a comparative analysis was also carried out on the as-deposited and annealed thin films. Several spectroscopy and microscopy techniques were considered for the characterization of structural (X-ray diffraction), morphological (SEM), chemical bonding (FTIR), and emission (PL spectroscopy) properties. The XRD results show that the thin films have an oriented c-axis hexagonal structure. SEM analysis validated the granular-like morphology of the deposited sample, and FTIR results confirm the presence of chemical bonding in deposited thin films. The photoluminescence (PL) emission spectra exhibit different peaks in the visible region when excited at different wavelengths. A sharp and intense photoluminescence peak was observed at 426 nm in the violet-blue region, which can be attributed to inter-band transitions due to the incorporation of Ni in AlN. Most of the peaks in the PL spectra occurred due to direct-band recombination and indirect impurity-band recombination. After annealing, the intensity of all observed peaks increases drastically due to the development of new phases, resulting in a decrease in defects and a corresponding increase in the crystallinity of the thin film. The observed structural, morphological, and photoluminescence results suggest that Ni: AlN is a promising candidate to be used in optoelectronics applications, specifically in photovoltaic devices and lasers. [ABSTRACT FROM AUTHOR]

The effect of Al addition on the microstructural evolution, hardness, and deformation behavior of a nanostructured CrCoNi medium entropy alloy prepared by co‐sputtering is studied in detail. With an increase in the Al content, the hardness of the alloy first increased (reaching 13.8 GPa) and then decreased (10.7 GPa), while the microstructure changed from nanocrystalline to a nanocrystalline/amorphous dual‐phase structure. During plastic deformation, the appropriate amounts of the amorphous region and nanocrystalline mixed structure prevent shearing and grain rotation. Moreover, the amorphous shell also acts as a dislocation source that emitted and absorbed dislocations constantly and prevented grain boundary sliding to some extent. This work provides a novel approach to improve the mechanical properties of nanostructured medium entropy alloy films by controlling their composition and microstructure. [ABSTRACT FROM AUTHOR]

Due to their outstanding power density, long cycle life and low cost, supercapacitors have gained much interest. As for supercapacitor electrodes, molybdenum nitrides show promising potential. Molybdenum nitrides, however, are mainly prepared as nanopowders via a chemical route and require binders for the manufacture of electrodes. Such electrodes can impair the performance of supercapacitors. Herein, binder-free chromium (Cr)-doped molybdenum nitride (Mo2N) TFEs having different Cr concentrations are prepared via a reactive co-sputtering technique. The Cr-doped Mo2N films prepared have a cubic phase structure of γ-Mo2N with a minor shift in the (111) plane. While un-doped Mo2N films exhibit a spherical morphology, Cr-doped Mo2N films demonstrate a clear pyramid-like surface morphology. The developed Cr-doped Mo2N films contain 0–7.9 at.% of Cr in Mo2N lattice. A supercapacitor using a Cr-doped Mo2N electrode having the highest concentration of Cr reveals maximum areal capacity of 2780 mC/cm2, which is much higher than that of an un-doped Mo2N electrode (110 mC/cm2). Furthermore, the Cr-doped Mo2N electrode demonstrates excellent cycling stability, achieving ~ 94.6% capacity retention for about 2000 cycles. The reactive co-sputtering proves to be a suitable technique for fabrication of binder-free TFEs for high-performance energy storage device applications. [ABSTRACT FROM AUTHOR]

The model to tailor the required chemical composition of thin films fabricated via multisource deposition, exploiting basic physicochemical constants of source materials, is developed. The model is experimentally verified for the two-source depositions of chalcogenide thin films from Ga–Sb–Te system (tie-lines GaSb–GaTe and GaSb–Te). The thin films are deposited by radiofrequency magnetron sputtering using GaSb, GaTe, and Te targets. Prepared thin films are characterized by means of energy dispersive X-ray analysis coupled with a scanning electron microscope to determine the chemical composition and by variable angle spectroscopic ellipsometry to establish film thickness. Good agreement between results of calculations and experimentally determined compositions of the co-deposited thin films is achieved for both the above-mentioned tie-lines. Moreover, in spite of all the applied simplifications, the proposed model is robust to be generally used for studies where the influence of thin film composition on their properties is investigated. [ABSTRACT FROM AUTHOR]

Amorphous oxide semiconductors are widely used in the backplane thin film transistors (TFTs) of displays and are extensively researched as materials for next-generation memory devices. However, they face reliability degradation due to stress factors such as thermal, bias, and light exposure. To mitigate these issues, extensive research is focused on improvements, including doping, enhancing crystallinity, and applying pre-and post-treatments. This study investigates the significantly improved reliability and electrical properties of amorphous indium gallium tin oxide (a-IGTO) TFTs by adopting a dual-channel configuration through simultaneous co-sputtering of HfO 2 and IGTO targets. The device fabrication involved co-sputtering HfO 2 and IGTO at the gate oxide interface, followed by depositing an IGTO-only layer, rather than doping the entire channel material. The effect of varying Hf concentration was evaluated by applying different HfO 2 sputtering powers. Optimal hafnium doping reduced the threshold voltage of the a-IGTO TFT from −0.85 V to 0.15 V compared to the pristine a-IGTO TFT, while enhancing the field-effect mobility (μ F E). Furthermore, the Hf-doped device exhibited improved stability, with a reduced threshold voltage shift (Δ V t h ) under positive (+15 V) and negative(-15 V) bias stress at 3000s, decreasing from 11.5 V to 4.8 V , and 4.7 V –1.1 V , respectively. This study proposes a novel device fabrication method to enhance the reliability of amorphous oxide semiconductor, addressing their inherent stress-related issues. [ABSTRACT FROM AUTHOR]

Improvement in crystallinity was investigated by compensating for stoichiometric deviations of non-selenization processed Cu0.9In0.7Ga0.3Se2 (CIGS) thin films due to highly volatile Se by co-sputtering them with Te followed by rapid thermal annealing. The prepared CIGS:Te thin films did not show any linear correlation between the compositional ratio and the co-sputtering time of Te; however, the deviation parameter (Δs) from the stoichiometry and normalized stoichiometric deviations of Se + Te and In + Ga were largely consistent with the behavior of thin-film properties. The proposed method provides better crystallinity with a large grain size, clear grain boundaries, and low microstrain and dislocation density, resulting in a large volume of the unit cell. The CIGS:Te thin films used as absorbers show improved optical properties compared to the conventional CIGS thin films, with Eg = 1.548 eV. These results can advance the low-cost commercialization of the enhanced-efficiency CIGS:Te thin films without the selenization process.

Heterojunction structures of n-ZnO/p-Si were prepared through the growth of undoped ZnO and (Gd, Al) co-doped ZnO films onto p-type Si (1 0 0) substrates, using a co-sputtering method. The structural and optical properties of the Gd-doped ZnO films were studied as a function of different Al doping concentrations. The X-ray diffraction profiles indicated that the films had a nanocrystalline structure of ZnO with a (0 0 2) preferential orientation. An increase in the Al doping concentration deteriorated the (0 0 2) diffraction peak intensity. The transmittance measurements in the UV–Vis wavelength range indicated that the film’s optical gap increased with increase in Al doping concentration. The heterojunction parameters were evaluated using the current–voltage (I-V) characterization carried out of the fabricated n-ZnO/p-Si heterostructure, in dark conditions at room temperature. From these measurements, the n-ZnO-based DMS/p-Si heterojunction diode with the use of (Gd, Al) co-doped ZnO film showed the lowest leakage current of 1.28 × 10−8 A and an ideality factor η of 1.11, close to the ideal diode behavior of η = 1, compared to the n-Gd-doped ZnO/p-Si and n-undoped ZnO/p-Si heterojunction diodes.

Nanostructured noble metals such as gold exhibit unique size‐dependent plasmonic and optical properties which is an enabling factor for designing nanophotonic devices. However, for its deployment in high temperature applications such as solar thermal energy harvesting and optothermal conversion, it requires understanding of its temperature dependent optical properties. This paper investigates the in situ specular reflectance of nanoporous gold (NPG) thin films in the wavelength range between 400 and 1000 nm at temperatures ranging from 25 to 500 °C via a home‐built fiber‐based optical spectrometer. During heating, the NPG's ligaments coalesce from an initial size of 39 ± 12 nm to a final size of up to 299 ± 114 nm, and its ligament scales with temperature closely matching an Arrhenius dependence. The surface roughness of NPG is empirically correlated to ligament size and temperature to allow for the theoretical prediction of the relative specular reflectance using scattering coefficients and effective medium theory which closely matches the experimental results. These results represent a step forward in using in situ optical spectroscopic methods to monitor the ligament size evolution of NPG thin‐films and to understand its stability and optical properties for applications at elevated temperatures. [ABSTRACT FROM AUTHOR]

Direct-methane solid oxide fuel cells (DMSOFCs) have recently attracted substantial attention due to their simplified system, reduced cost, and the direct availability of methane fuel obtained from natural gas. Among oxygen-ion conductive materials, doped-ceria such as gadolinium-doped ceria (GDC) or samarium-doped ceria can be incorporated into Ni-based anodes to reinforce their coking resistance, enlarge their electrochemical reaction area, and improve the kinetics of the internal reforming/electrochemical oxidation of methane. To reduce the range of operating temperatures of DMSOFCs while maintaining their performance, the thin film deposition technique of magnetron sputtering was adopted in this work. An Ni-GDC thin-film anode and a Pt thin-film cathode were deposited on scandia-stabilized zirconia (ScSZ) electrolyte supports. This fuel cell was tested with directly supplied methane fuel (3% H 2 O) at 500 °C. The results demonstrated the effects of the GDC volume fraction in the anode—which was controlled by co-sputtering power—on open circuit voltage and electrochemical performance. The co-sputtered Ni-GDC anode was able to survive through 36-h operation, although there was some performance degradation. Field-emission scanning electron microscopy results revealed no formation of filamentous carbon on the Ni catalysts, despite the fact that both X-ray photoelectron spectroscopy and Raman spectroscopy analyses detected carbon coking. The relatively high performance and resistance to carbon coking of co-sputtered thin-film anode were attributed to its intrinsic small grain size. [ABSTRACT FROM AUTHOR]

This work focused on the microstructure and mechanical properties of (Mo, Hf)N coatings deposited by radio frequency reactive magnetron co-sputtering technique with input power modulation. The coating characteristics, including indentation hardness, modulus, and tribological behavior, were discussed in terms of deposition parameter, composition, phase, and microstructure. The (Mo, Hf)N thin films were fabricated at a fixed Ar/N2 inlet gas ratio of 12/8 sccm/sccm and modulated input powers. The input power of Mo was fixed at 150 W, while that of the Hf target was managed from 25 to 200 W. The deposition rate and the Hf content of the (Mo, Hf)N coatings increased with input power. The (Mo, Hf)N ternary nitride coatings showed a polycrystalline microstructure with B1-MoN(111), β-Mo2N (112), γ-Mo2N(111), (200), and MoN2(200) phases in X-ray diffraction patterns as input power modulation were 150/25 to 150/100 W/W. The multiple phase microstructure feature and detail crystal development were demonstrated through transmission electron microscopy. According to nanoindentation and wear test results, ternary (Mo, Hf)N coatings represented more improved mechanical characteristics than the MoN and HfN binary nitride films. The 150/100 W/W deposited (Mo, Hf)N coating exhibited a highest hardness of 22.5 GPa when Hf content was at 5.6 at.%. The superior anti-wear behavior of this film with least wear damage was observed as well. The multiphase and solid-solution strengthening of the (Mo, Hf)N coatings, i.e., a microstructure feature of mixed B1-MoN, β-Mo2N, γ-Mo2N, and MoN2 phases and Hf doping in MoN, were the responsible for the superior mechanical and tribological behavior for the (Mo, Hf)N coatings. [ABSTRACT FROM AUTHOR]

Nanostructured titanium chromium nitride (TiCrN) thin films were deposited on Si by reactive DC magnetron co-sputtering technique. The effects of N2 gas flow rates on the structure of the TiCrN films were studied. The crystal structure, microstructure, surface morphology, thickness, composition, and hardness were characterized by GI-XRD, FE-SEM and EDS, and nanoindentation techniques, respectively. The oxidation behavior of the films was carried by annealing in the air. The oxidation activation energies were calculated using the Arrhenius equation. The results revealed that the as-deposited thin films were formed as a (Ti, Cr) N solid solution with the fcc type phase. The films showed a nanocrystalline structure with crystal sizes less than 20 nm. The lattice constants were in the range of 4.144 to 4.181 Å. The thickness of the TiCrN films decreased from 767 to 415 nm with increasing of the N2 gas flow rates. The N content of the films was increased with increasing of the N2 gas flow rates, while the Ti and Cr content were decreased. The TiCrN thin films showed compact columnar and dense morphology as a result of the N2 gas flow rate. The hardness of the TiCrN thin film was in the range of 38.2 to 70.8 GPa. The oxide phases of TiO2 structure with strong preferred orientation (101) plane has appeared from 700°C. The oxidation rate was increased from 9.29x10-13 to 1.32x10-12 cm²/s as an increase in annealing temperature. Finally, the oxidation activation energy of 10.98 kJ/mol was calculated in this work. [ABSTRACT FROM AUTHOR]

Oxide semiconductors have been considered one of the most promising candidates for flexible electronics applications owing to their low process temperatures and good reliability. However, the low mobility of p-type oxide semiconductors limits the performance of flexible oxide-TFT-based CMOS technology. In this study, p-type SnOx:Ni thin films were deposited by reactive rf magnetron co-sputtering, a technique compatible with the current industrial semiconductor manufacturing technology, from Sn and Ni targets. As the Ni-gun power increased, the distribution of Ni in the SnOx:Ni thin film changed from a more uniform dispersion to nanoclusters, resulting in the crystalline phase transition of SnOx:Ni from $\alpha $ -SnO (110)-dominant polycrystalline to amorphous and then to $\alpha $ -SnO (101)-dominant polycrystalline. A high-mobility inverted-staggered p-type SnOx:Ni TFT was then fabricated on a glass substrate with a maximum process temperature of 225°C, which is compatible with flexible polymeric substrates. The TFT fabricated at an optimal Ni-gun power of 42 W exhibited an impressive field-effect mobility of 11 cm2V−1s−1 and on current of $35.2 ~\mu \text{A}$ per channel width-to-length ratio; these values are comparable to those of a typical n-type oxide TFT. These results should contribute toward flexible oxide-TFT-based CMOS technology. [ABSTRACT FROM AUTHOR]

Bimetallic nanostructure of noble metals is an alternative material that can provide the tenability of plasmonic performance. In this study, the plasmonic silver–titanium nanoisland (Ag–Ti NI) films deposited on a silicon wafer and glass slide substrates were prepared by magnetron co-sputtering of high-purity Ag target (99.99%) operated at 100 W-DC source, and Ti target (99.99%) operated at 50–250 W-DC pulsed source. The surface morphologies of the prepared films revealed a noncontinuous island Ag–Ti according to the formation of thin film growth based on the Volmer–Weber model. An increase in the sputtering power of the Ti target caused an evident increase in the Ag–Ti NIs diameter. The localized surface plasmon resonance (LSPR) was evaluated by UV–Vis–NIR spectrophotometry. The LSPR peak shift disappears with an increase of the sputtering power of the Ti target.In addition, the results confirmed that the surface-enhanced Raman scattering (SERS) activity of the bimetallic Ag–Ti NIs significantly improved in performance and stability, which is promising for the application in analytical chemistry. [ABSTRACT FROM AUTHOR]

This study demonstrated a silver (Ag) and samarium-doped ceria (SDC) mixed ceramic and metal composite (i.e., cermet) as a cathode for low-temperature solid oxide fuel cells (LT-SOFCs). Introducing the Ag-SDC cermet cathode for LT-SOFCs revealed that the ratio between Ag and SDC, which is a crucial factor for catalytic reactions, can be tuned by the co-sputtering process, resulting in enhanced triple phase boundary (TPB) density in the nanostructure. Ag-SDC cermet not only successfully performed as a cathode to increase the performance of LT-SOFCs by decreasing polarization resistance but also exceeded the catalytic activity of platinum (Pt) due to the improved oxygen reduction reaction (ORR). It was also found that less than half of Ag content was effective to increase TPB density, preventing oxidation of the Ag surface as well.

Thin films of transition metal oxides and oxynitrides have proven highly effective in protecting stainless steels against corrosion in both chemically aggressive environments and biological fluids. In the present work, cerium zirconium oxynitride thin films were deposited to enhance the corrosion resistance of surgical-grade stainless steel to be used in osteosynthesis processes. Two techniques were employed: co-sputtering and radiofrequency (RF) sputtering, and the morphology and corrosion efficiency of the coatings deposited by each technique were evaluated. X-ray diffraction, X-ray photoelectron spectroscopy and field emission transmission electron microscopy were used to characterize the morphological and chemical structure, respectively. Additionally, the corrosion resistance of the oxynitride-coated surgical grade stainless steel system (ZrCeO x N y -AISI 316L) was assessed using Hank's solution as the corrosive electrolyte, to determine its resistance to corrosion in biological media. The results show that ZrCeO x N y coatings increase the corrosion resistance of surgical grade stainless steel by two orders of magnitude and that the Ce(III)/Ce(IV) equilibrium decreases the corrosion rate, thereby increasing the durability of the steel in a biological environment. The results show that Ce coatings increase the corrosion resistance of surgical grade stainless steel by two orders of magnitude and that the Ce(III)/Ce(IV) equilibrium decreases the corrosion rate, thereby increasing the durability of the steel in a biological environment.

In this research, a nanoporous platinum film is synthesized using the dealloying method. Platinum–copper (Pt–Cu) alloy films with a thickness of approximately 50 nm are prepared on glass using the magnetron-co-sputtering technique. In order to obtain nanoporous Pt, the Pt–Cu alloy films are dealloyed in 1 M nitric acid solution for different intervals. It is observed that when dealloyed in the nitric acid solution for 5 h, Cu was completely removed from the alloy, and nanoporous Pt with a regular pore structure was obtained. Then, the fabricated nanoporous Pt film is tested for hydrogen detection in the concentration range of 10 ppm and–5% hydrogen at various temperatures. The results demonstrated that the sensitivity of nanoporous Pt is about 6.5 for exposure to 1% hydrogen, and the sensing mechanism of nanoporous Pt could be explained by the surface scattering phenomenon.

This study explored the structural characteristics, mechanical properties, and oxidation behavior of W-enriched TaWSiN films prepared through co-sputtering. The atomic ratios [W/(W + Ta)] of the as-deposited films maintained a range of 0.77–0.81. The TaWSiN films with a Si content of 0–13 at.% were crystalline, whereas the film with 20 at.% Si was amorphous. The hardness and Young’s modulus of crystalline TaWSiN films maintained high levels of 26.5–29.9 GPa and 286–381 GPa, respectively, whereas the hardness and Young’s modulus of the amorphous Ta7W33Si20N40 films exhibited low levels of 18.2 and 229 GPa, respectively. The oxidation behavior of TaWSiN films was investigated after annealing at 600 °C in a 1%O2–Ar atmosphere, and cone-like Ta0.3W0.7O2.85 oxides formed and extruded from the TaWSiN films.

Aluminum nitride (AlN) is a semiconductor material possessing a hexagonal wurtzite crystal structure with a large band gap of 6.2 eV. AlN thin films have several potential applications and areas for study, particularly in optoelectronics. This research study focused on the preparation of Ni-doped AlN thin films by using DC and RF magnetron sputtering for optoelectronic applications. Additionally, a comparative analysis was also carried out on the as-deposited and annealed thin films. Several spectroscopy and microscopy techniques were considered for the characterization of structural (X-ray diffraction), morphological (SEM), chemical bonding (FTIR), and emission (PL spectroscopy) properties. The XRD results show that the thin films have an oriented c-axis hexagonal structure. SEM analysis validated the granular-like morphology of the deposited sample, and FTIR results confirm the presence of chemical bonding in deposited thin films. The photoluminescence (PL) emission spectra exhibit different peaks in the visible region when excited at different wavelengths. A sharp and intense photoluminescence peak was observed at 426 nm in the violet-blue region, which can be attributed to inter-band transitions due to the incorporation of Ni in AlN. Most of the peaks in the PL spectra occurred due to direct-band recombination and indirect impurity-band recombination. After annealing, the intensity of all observed peaks increases drastically due to the development of new phases, resulting in a decrease in defects and a corresponding increase in the crystallinity of the thin film. The observed structural, morphological, and photoluminescence results suggest that Ni: AlN is a promising candidate to be used in optoelectronics applications, specifically in photovoltaic devices and lasers.

[Display omitted] • Single crystal CrB 1.7 /TiB 2.3 superlattices grown by magnetron co-sputter epitaxy. • Epitaxial growth with high adatom mobility of CrB 1.7 giving abrupt top interfaces. • TiB 2.3 layers display rough top interfaces indicating a kinetically limited growth. • Control over the B content in TiB y (0.9 ≤ y ≤ 3.3) by co-sputtering of Ti + TiB 2. • 2D epitaxial growth for superlattices vs. 3D columnar growth of single layers. Single-crystal CrB 2 /TiB 2 diboride superlattices with well-defined layers are promising candidates for neutron optics. However, excess B in sputter-deposited TiB y using a single TiB 2 target deteriorates the structural quality of CrB x /TiB y (0001) superlattices. We study the influence of co-sputtering of TiB 2 + Ti on the stoichiometry and crystalline quality of 300-nm-thick TiB y single layers and CrB x /TiB y (0001) superlattices on Al 2 O 3 (0001) substrates grown by DC magnetron sputter epitaxy at growth-temperatures T S ranging from 600 to 900 °C. By controlling the relative applied powers to the TiB 2 and Ti magnetrons, y could be reduced from 3.3 to 0.9. TiB 2.3 grown at 750 °C exhibited epitaxial domains about 10x larger than non-co-sputtered films. Close-to-stoichiometry CrB 1.7 /TiB 2.3 superlattices with modulation periods Λ = 6 nm grown at 750 °C showed the highest single crystal quality and best layer definition. TiB 2.3 layers display rough top interfaces indicating kinetically limited growth while CrB 1.7 forms flat and abrupt top interfaces indicating epitaxial growth with high adatom mobility. [ABSTRACT FROM AUTHOR]

By combining Gd dopant induction and magnetron sputtering technique, vertically-aligned Gd-doped WO 3 nano-stalagmite arrays (GW-NSs) have been first constructed on the ITO-coated glass substrate, which exhibits a significantly improved electrochromic and capacitive performance. Moreover, an electrochromic energy storage smart window (EESW) device is further fabricated by assembling the GW-NSs electrode and an opposite NiO electrode toward practical bifunctional application. [Display omitted] • Gd-doped WO 3 nano-stalagmites (GW-NSs) array with vertical alignment have been successfully synthesized on ITO-coated glass substrates via co-sputtering method, which can possess optimized aspect ratio and array density by precise parameter optimal design (Gd/W, sputtering times, etc). • The optimized GW-NSs film exhibits a significantly improved electrochromic and capacitive performance, which could be attributed to its large surface area of nano-array structures induced by Gd doping, significantly increasing the number of the active sites and meanwhile facilitate the Li+ ions diffusion. • Dual-functional smart window device assembled with the GW-NSs and NiO counter electrode is demonstrated with ability to visually monitor the level of stored energy from the rapid and reversible color variation, indicating the potential applications of GW-NSs in both electrochromic and energy-storage fields. Gd-doped WO 3 nano-stalagmites (GW-NSs) film has been successfully prepared on indium-doped tin oxide (ITO)-coated glass substrates by co-sputtering deposition. Gd dopants can facilitate the vertically-aligned growth of WO 3 nano-stalagmites on the WO 3 -nanoparticle seed layer. The microstructure analysis shows that the GW-NSs film with optimized aspect ratio and array density is fabricated with Gd/W = 0.6 % in atomic ratio. Such GW-NSs electrode (active area: 1 × 1.5 cm2) exhibits large transmittance modulation (ΔT = 52.7 % at 633 nm), high coloration efficiency (87.3 cm2 C−1 at 633 nm), fast switching speed (5.9/13.1 s for coloration/bleaching), large diffusion coefficient (9.52 × 10−10 cm2 s−1) and long-term cycling stability (>2000) under an applied voltage of ± 1.0 V, which can be attributed to a shorten Li+ diffusion distance and a large-area contact with the electrolyte. Importantly, the GW-NSs film also shows superior capacitive performance (calculated areal capacitance of 8.44 mF cm−2 at 0.4 mA cm−2) and long-term cyclic stability (capacitance retention rate is 87.4 % after 2000 cycles). Furthermore, we fabricated the bifunctional smart window device combined with NiO counterpart electrode, which has the ability to visually monitor the level of stored energy from rapid and reversible coloration, indicating the potential applications of GW-NSs in both electrochromic and energy-storage fields. [ABSTRACT FROM AUTHOR]

Platinum (Pt) and Samaria-doped ceria (SDC) as cermet cathodes were investigated to enhance oxygen reduction reaction (ORR) kinetics in low-temperature solid oxide fuel cells (SOFCs). Pt is widely known for its high catalytic activity, whereas SDC is one of the most promising oxide ionic conductors as an LT-SOFC electrolyte. To improve both the catalytic activity and oxygen ionic transportation, a co-sputtering technique was used to fabricate a composite cathode by adjusting the elemental composition of Pt and SDC. This technique demonstrated that the Pt-SDC cermet cathode can increase the electrochemical reaction sites and offer a percolated pathway for rapid electron-ion conduction within the cermet structure. The electrochemical analysis results also revealed that the fuel cells coated with Pt-SDC cermet cathodes outperformed the pure Pt-coated fuel cells in terms of peak power density. The electrochemical impedance spectroscopy analysis indicated that the improved ORR kinetics of Pt-SDC cermet cathodes were the main reason for the improved fuel cell performance by catalyzing both electron and oxygen ion conduction. • Pt-SDC cermet cathodes were fabricated via co-sputtering technique for LT-SOFCs. • The chemical composition of cermet cathodes was controlled by RF power of SDC. • The TPB density can be enlarged by mixing the both Pt and SDC with co-sputtering. • Optimized ratio of Pt and SDC can provide the percolating path for charge transport. • Pt-SDC cermet cathode can increase the performance of fuel cell by catalyzing ORR. [ABSTRACT FROM AUTHOR]

In deposition of nitride films through reactive sputtering, the degree of nitrogen dissociation from N 2 in vacuum chambers is small and difficult to control, while the nitrogen sputtered from a nitride target is in the ionic state, reactive, and tunable through the power of the target. In this study, co-sputtering of TaN target and Ta target is used to prepare tantalum nitride films of Ta 2 N phase with low resistance and low temperature coefficient of resistance (TCR). We investigated effects of the power of the TaN target and annealing temperature on the phase, structure, and electrical properties of the thin films, and obtained an optimal Ta 2 N-phase thin-film with adjustable resistance in the low segment and a TCR of −8 ppm/°C. • The metal Ta atoms from the Ta target easily take over the ion state N component from the TaN target. • Tantalum nitride films with low resistance and low TCR were successfully prepared by co-sputtering Ta and TaN targets. • Vacuum annealing at a medium temperature improves the electrical properties of the film. • The best tantalum nitride film has a square resistance of 2.586 Ω·□−1, a resistivity of 243.084 μΩ·cm, and a TCR of −8 ppm/°C. [ABSTRACT FROM AUTHOR]

The model to tailor the required chemical composition of thin films fabricated via multisource deposition, exploiting basic physicochemical constants of source materials, is developed. The model is experimentally verified for the two-source depositions of chalcogenide thin films from Ga–Sb–Te system (tie-lines GaSb–GaTe and GaSb–Te). The thin films are deposited by radiofrequency magnetron sputtering using GaSb, GaTe, and Te targets. Prepared thin films are characterized by means of energy dispersive X-ray analysis coupled with a scanning electron microscope to determine the chemical composition and by variable angle spectroscopic ellipsometry to establish film thickness. Good agreement between results of calculations and experimentally determined compositions of the co-deposited thin films is achieved for both the above-mentioned tie-lines. Moreover, in spite of all the applied simplifications, the proposed model is robust to be generally used for studies where the influence of thin film composition on their properties is investigated.