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Because of its high stability, good wear resistance, and high mechanical hardness, SiC is widely used in various mechanical parts as a protective film. However, there have been few reports published on the preparation of SiC films by pulsed DC magnetron sputtering. In this work, SiC films were deposited onto glass and ceramic substrates from a sintered SiC target through pulsed DC magnetron sputtering. The influence of the variation of the power pulse frequency (0 kHz, 50 kHz, 150 kHz, 250 kHz, and 300 kHz) on the film's performance was studied. The surface morphology, structural characteristics, hardness, and adhesion strength of the deposited SiC films were investigated here. The results show that all the deposited films adhered well to the substrate. They were smooth, compact, and presented an amorphous structure. The film hardness was found to increase as the pulse frequency was increased. When the pulse frequency was 250 kHz, the resulting SiC film possessed optimal mechanical properties with a hardness of 25.74 GPa (measured using a nanometer indentation instrument) and an adhesion strength of about 36 N (measured by scratch tester). [ABSTRACT FROM AUTHOR]

Close-packed TiO2 nanotube arrays are prepared on metallic Ti surface by electrochemical anodization. Subsequently, by magnetron sputtering, Au nanoparticles are coated onto the top sidewall and tube inwall. The Au@TiO2 systems can effectively kill Staphylococcus aureus and Escherichia coli in darkness due to the existence of Au nanoparticles. On the basis of classical optical theories, the antibacterial mechanism is proposed from the perspective of localized surface plasmon resonance. Respiratory electrons of bacterial membrane transfer to Au nanoparticles and then to TiO2, which makes bacteria steadily lose electrons until death. This work provides insights for the better understanding and designing of noble metal nanoparticles-based plasmonic heterostructures for antibacterial application. [ABSTRACT FROM AUTHOR]

Abstract: The kinetic behaviors of Li-ion insertion/extraction in LiV3O8 thin film have been investigated using cyclic voltammetry (CV), potentiostatic intermittent titration (PITT) and electrochemical impedance spectroscopy (EIS) method. This LiV3O8 thin film with a mixed amorphous-nanocrystalline microstructure was fabricated by RF sputtering. For the first time, the intrinsic kinetics of LiV3O8 thin film electrode is obtained. The value is about 10−13 cm2/s in mixed amorphous-nanocrystalline microstructure LiV3O8 thin film. Different to crystalline LiV3O8 thin film, the values do not change a lot with the increase of cell potential which is due to the absence of structural phase transition behavior in mixed microstructure LiV3O8 thin film during Li+ insertion/extraction process. This is also the reason for excellent capacity retention performance of LiV3O8 film with a mixed microstructure. [ABSTRACT FROM AUTHOR]

Abstract: LiV3O8 thin films with a mixed amorphous–nanocrystalline microstructure were deposited on stainless steel substrates using radio-frequency (RF) magnetron sputtering for the first time. The films exhibited good performance as a cathode material for lithium ion batteries. Results indicate that the film electrodes had a smooth surface and consisted mainly of an amorphous structure containing nanocrystalline zones dispersed within it. Depending on its microstructure, the films delivered an initial discharge capacity as high as 382mAh/g and exhibited good capacity retention, with discharge capacity of 301mAh/g after 100 cycles representing a loss rate of 0.21% per cycle. [Copyright &y& Elsevier]

In this study, an all-solid-state electrochromic device (ECD) with the structure of ITO/WO 3 /Al 2 SiO 5 /NiO x /ITO was prepared, and the effect of the Al 2 SiO 5 solid electrolyte thicknesses on the opto-electrical performance was investigated. The microstructure and surface morphology were characterized using XRD, SEM and AFM, and the surface morphology and degree of surface looseness demonstrate a significant influence on the opto-electrical properties of ECDs. The charge transfer dynamics at the solid-solid interface were characterized using EIS to obtain an ionic conductivity of 4.637 × 10-8 S/cm. CV, CA and UV–Visible spectra were employed to record the in situ electrochemical and optical properties. The results revealed that the highest optical modulation was 44.58%, the coloring and bleaching times were 14.8 s and 3.7 s, and the highest coloring efficiency was 98.17 cm2/C, which indicates that excellent opto-electrical properties were obtained. When the thickness increases, the degree of surface dense morphology transforms, and the loose morphology is more favorable for ion conductivity, which improves the opto-electrical properties. The results in this study provide insights into the understanding of Al3+-based all-solid-state ECDs, which promote the exploration of new types of Al3+ ionic conductors for all-solid-state ECDs. [ABSTRACT FROM AUTHOR]

Abstract: Ga–F codoped ZnO (GFZO) thin films were firstly prepared on polycarbonate (PC) substrates by MF magnetron sputtering and the results were compared in detail with the Al doped ZnO (AZO) thin films. The influence of dopants on the structural and optoelectric properties of ZnO films was studied. X-ray diffraction and scanning electron microscopy results show that the cracks formed in both GFZO and AZO films due to the high residual stress, originating from the different thermal expansion coefficients between film/substrate. However, the GFZO films show better crystallinity and deliver larger grain size than AZO. A relative low resistivity of 1.4 × 10−3 Ω cm and a transmittance of 81% for the GFZO thin films are achieved, better than that of 2.3 × 10−2 Ω cm and 75% for the AZO films. The results illustrate that the combined effects of Ga–F codoping and smaller crack density can optimise the opto-electric properties of ZnO based thin films. [Copyright &y& Elsevier]

Tungsten oxide (WO3) is widely used as a functional material for "smart windows" due to its excellent electrochromic properties, however it is difficult to overcome the conflict between its optical modulation and cyclic stability. In this work, WO3 thin films with different crystal structures were prepared by DC reactive magnetron sputtering method. The effects of substrate temperature on the structure, composition, and electrochromic properties of WO3 films were investigated. The results show that the crystallinity of the WO3 film increases with increasing deposition temperature, indicating that temperature plays an important role in controlling the structure of the WO3 film. For WO3 thin films formed at a substrate temperature of 573 K, the film is in an amorphous state to a crystalline transition state. From X-ray diffraction (XRD) analysis, the thin film showed a weak WO3 crystallization peak, which was in the composite structure of amorphous and nanocrystalline. Which has the best electrochromic properties, with modulation amplitude of 73.1% and bleached state with a coloration efficiency of 42.9 cm2/C at a wavelength of 550 nm. Even after 1500 cycles, the optical modulation still contains 65.4%, delivering the best cyclic stability. [ABSTRACT FROM AUTHOR]

CuCrO2 is one of the most promising p-type transparent conductive oxide (TCO) materials. Its electrical properties can be considerably improved by Mg doping. In this work, Cr-deficient CuCrO2 thin films were deposited by reactive magnetron sputtering based on 5 at.% Mg doping. The influence of Cr deficiency on the film's optoelectronic properties was investigated. As the film's composition varied, CuO impurity phases appeared in the film. The mixed valency of Cu+/Cu2+ led to an enhancement of the hybridization between the Cu3d and O2p orbitals, which further reduced the localization of the holes by oxygen. As a result, the carrier concentration significantly improved. However, since the impurity phase of CuO introduced more grain boundaries in Cu[Cr0.95−xMg0.05]O2, impeding the transport of the carrier and incident light in the film, the carrier mobility and the film's transmittance reduced accordingly. In this work, the optimal optoelectronic performance is realized where the film's composition is Cu[Cr0.78Mg0.05]O2. Its Haacke's figure of merit is about 1.23 × 10−7 Ω−1. [ABSTRACT FROM AUTHOR]

Cu2O thin film has been widely studied due to its intrinsic p-type conductivity. It can be used as p-type transparent conductive electrode or hole transport layer in various potential applications. However, its intrinsic p-type conductivity is very limited, which needs to be optimized by introducing acceptor defects. In this work, the electrical properties of the Cu2O films was improved through introducing interstitial oxygen in the films those were deposited via direct current sputtering assisted by oxygen ion beam. The results show that with oxygen ion beam current increase, the carrier concentration effectively improves. However, with more interstitial oxygen introduced, the film's crystallinity significantly reduces, as well as the carrier mobility decreases. Meanwhile, all of the Cu2O films present moderate transmittance in the visible region (400–800 nm), but ideal transmittance in the near infrared (NIR) light region (800–2500 nm). When compared with the strong reflection of the n-type transparent conductive film to the near infrared light, the Cu2O film is transparent conductive in NIR region, which expands its application in the fabrication of NIR electrical devices. [ABSTRACT FROM AUTHOR]

Indium tin oxide/silver/indium tin oxide (ITO/Ag/ITO, IAI) multilayer structures were prepared by DC magnetron sputtering as a conductive transparent electrode for inorganic all-solid-state electrochromic devices. A thin layer of silver (Ag) with various thicknesses was inserted between two layers of ITO films. The XRD and SEM results revealed that the microscopic morphology of Ag film was closely related to the thickness. Besides, the electrical and optical properties of the IAI multilayers were significantly influenced by the Ag layer thickness. The optimized IAI multilayers demonstrated the best combination of electrical and optical properties with a figure of merit of 54.05 (sheet resistance of 6.14 Ω/cm2and optical transmittance of 90.83%) when the Ag film was 10 nm thick. In order to evaluate the IAI multilayers as a transparent electrode for electrochromic applications, two ECDs with the structures of ITO/NiO x /LiPON/WO 3 /ITO and ITO/NiO x /LiPON/WO 3 /IAI were prepared, and their electro-optical properties were characterized by cyclic voltammetry (CV), chronoamperometry (CA) and spectroscopic measurements. Compared with ECD the pure ITO top electrode (ITO/NiO x /LiPON/WO 3 /ITO), the ECD with the IAI top electrode (ITO/NiO x /LiPON/WO 3 /IAI) presented a slightly smaller optical modulation amplitude, but a faster switching speed. All our findings indicate that the IAI multilayer structure is a promising alternative to the ITO thin film for inorganic all-solid state electrochromic applications. [ABSTRACT FROM AUTHOR]

Amorphous lithium phosphorus oxynitride (LiPON) films of various thicknesses were prepared by radio frequency (RF) magnetron sputtering as an electrolyte layer for inorganic all-solid-state electrochromic devices.The ionic conductivity of LiPON films measured by electrochemical impedance spectroscopy was all approximately 10−6 S/cm, and the average optical transmittance characterized by UV–Vis spectroscopy was over 80%, indicating that the prepared LiPON films were suitable for electrochromic applications. Monoclinic electrochromic devices (ECDs) (ITO/NiO x /LiPON/WO 3 /ITO) with different LiPON thicknesses were fabricated and studied. It was found that the electro-optical properties of the ECDs could be significantly affected by the thickness and surface roughness of LiPON films. The ECDs demonstrated the best combination of optical contrast (68.4% at 560 nm), switching time (27s), and cycling stability (optical modulation degradation of 6.93% for 200 cycles) when the LiPON thickness was 450 nm. The above results not only shed lights on improving the interfacial properties of solid electrolytes, but also give directions for the performance enhancement of inorganic all-solid electrochromic devices. • ITO/NiO x /LiPON/WO 3 /ITO all-solid-state ECDs with different LiPON thicknesses were fabricated and studied. • The mechanism of solid electrolyte thickness affecting interfacial properties is discussed. • This mechanism relies on the effect of electrolyte surface roughness on interfacial contact properties. • The electro-optical properties and cycling stability of the ECDs are be deeply dependent on the electrolyte thickness. [ABSTRACT FROM AUTHOR]

Traditional oxide transparent conductive materials are very brittle, resulting in greatly reduced optoelectronic performance under bending. An effective solution is embedding flexible conductive materials, such as Ag or Cu, into the ceramic oxides. Here, AZO/Ag multilayers were deposited on glass and polyethylene terephthalate (PET) substrates by magnetron sputtering at room temperature. The influence of the various layered structures (AZO/Ag/AZO, AZO/Ag/AZO/Ag/AZO, or AZO/Ag/AZO/AZO/Ag/AZO) on the optoelectronic properties of the multilayers was investigated. The results show that the resistivity of AZO thin film with an embedded Ag layer is significantly reduced, especially when the Ag layer is thick enough to become continuous. Additionally, the electrical stability of AZO thin film under bending was greatly enhanced when embedded with a continuous Ag layer. The resistance of AZO/Ag/AZO/Ag/AZO five-layer film remained almost unchanged even as the bending angle reached 172°. The results indicate that a multilayer structure of AZO/Ag films has great potential in flexible electrode applications. [ABSTRACT FROM AUTHOR]

As an optical property with excellent dielectric properties combined with antireflection, AlSiON is not currently being investigated as electrochromic devices. Based on the optimized Al3+ solid-state electrolyte Al 2 SiO 5 , which is doped with different levels of N elements, the opto-electrical properties of the formed AlSiON in electrochromic devices have been systematically examined. AlSiON with an N-doping ratio of 3.4% achieves outstanding optical modulation (58.17%) and switching speed (22.2 s for coloring and 3.5 s for bleaching), as well as an effective reduction of leakage currents (68.39 μA/cm2) in electrochromic devices. By XPS analysis, the N content of 3.4% AlSiON is internally bonded with a proportion of Si–N to Al–N bonds, which generates a dielectric high Si 3 N 4 composition effectively blocking electron breakdown. • The opto-electrical properties of AlSiON synthesized based on Al 2 SiO 5 further doped with N elements as an electrolyte for electrochromic devices were investigated for the first time and good electrochromic properties were obtained, broadening the system for the Al ionic electrolyte system. • The doping of N elements improves the dielectric properties of the AlSiON electrolyte, effectively blocking the leakage current and limiting the electron conduction rate to within the order of 10−11 S/cm, while also increasing the number of transferred charges in AlSiON. The electron leakage from electrochromic devices is alleviated. • The AlSiON ionic conductor device with an N content of 3.4 at.% achieved an optical modulation amplitude of 58.15 %, a coloring time of 22.2 s, a bleaching time of 3.5 s, and reduced the leakage current to 68.39 μA, with only a 9 % decrease in the optical modulation amplitude after 640 cycles. [ABSTRACT FROM AUTHOR]

Hydrogenated Al-doped diamond-like carbon films were prepared in a hybrid plasma system combines magnetron sputtering and anode layer ion source, which allows independent control of the incorporated-Al content and carbon film structure. In order to achieve gradual structure and property transition from substrate to DLC film, a functionally gradient interlayer Cr/CrC x /Cr x Al y C was tailored deposited. The influence of methane flow rate on chemical composition, morphologies, and microstructure of the resultant films were studied. The residual stress, mechanical and tribological properties were investigated by using laser stress-tester, nano-indentation and ball-on-disc tribo-meter, respectively. The results suggested that the Al-DLC films have a characteristic of amorphous structure and the incorporated Al atoms were dissolved in the matrix without bonding with C atoms. A significant residual stress reduction was found in Al-doped DLC film compared with pure one (3.8 GPa). The Al-DLC film deposited at the optimum methane flow rate exhibited a unique combination of desirable properties, including moderate hardness, good adhesion strength, low friction coefficient and good wear resistance, which make it a promising candidate as protective films for engineering applications. [ABSTRACT FROM AUTHOR]

• Wear behavior can be adjusted by Si content and multilayer structure. • Wear rate of Si-DLC film displayed a different changing trend from H/E*. • Besides graphitization, friction can also generate more sp3 bonds in Si-DLC film. Modulation of Si on microstructure and tribomechanical properties of hydrogen-free DLC films was studied by preparing Si-DLC films through a hybrid HiPIMS and middle-frequency magnetron sputtering deposition technique. Atomic force microscope, scanning electron microscope, transmission electron microscope, Raman spectrometer and X-ray photoelectron spectroscopy were used to investigate film chemical composition and microstructure. Hardness and elastic modulus were characterized by a nanoindenter. Friction coefficient was measured by a ball-on-disk tribometer. 3D surface profiler, optical microscope and Raman spectrometer were applied to study the tribological behaviors of Si-DLC films. Films surface roughnesses (Ra) are in the range of 1.18–3.15 nm. Si-DLC layer presents a Si-rich/Si-poor multilayer microstructure with a period of about 4 nm. With the rise of Si content in Si-DLC film, sp3 content, hardness and elastic modulus increase. Most Si atoms are interspersed in the amorphous carbon matrix and bond with carbon atoms forming Si-C bonds. The lowest wear rate of 3.5 × 10-7 mm3/Nm is obtained as Si content in Si-DLC film is 14.8%. Varying Si contents in Si-DLC films generated different bonding states of wear tracks, leading to the different wear behaviors of Si-DLC films. [ABSTRACT FROM AUTHOR]

Al-containing amorphous carbon (a-C:Al) films were fabricated under different working pressures by high-power impulse magnetron sputtering. Morphologies, microstructure and chemical composition of a-C:Al films were characterized by scanning electron microscopy, atomic force microscope, X-ray photoelectron spectroscopy, transmission electron microscopy and Raman spectroscopy. Mechanical properties and tribological behavior of a-C:Al films were investigated by film stress tester, nano-indentation, scratch tester, ball-on-disk tribometer and 3D surface profiler. Results showed that atomic composition of Al in a-C:Al films was about 5%, independent of working pressure. The prepared films have smooth surfaces with Ra of 2.22 nm–5.89 nm. Typical amorphous structures could be observed in a-C:Al films and sp3 content could be governed by changing working pressures. Al existed as an oxide of aluminum in carbon matrix. There was a notable negative correlation between internal stress and sp3-C content. All samples manifested good adhesion strength to substrates with critical loads beyond 70 N. Wear rates were in 10−8 mm3 N−1 m−1 order of magnitude and had the same changing trend with H/E as working pressure rose from 0.3 Pa to 0.6 Pa. a-C:Al film prepared at 0.4 Pa has the best wear resistance with a wear rate of 4.38 × 10−8 mm3 N−1 m−1. • a-C:Al films were prepared by HiPIMS with a self-made C–Al composite target. • There was a notable negative correlation between internal stress and sp3-C content. • Wear rate and H/E showed the same trend as working pressure varied. • Wear rate of a-C:Al film could be as low as 4.38 × 10−8 mm3 N−1 m−1. [ABSTRACT FROM AUTHOR]