Search

Anion doping is an efficient method for modifying the electrical property of the p‐type semiconductor CuI. However, adjustment of the hole density is still challenging. Using sputtering and spin coating techniques, well‐controlled S‐doping of CuI thin films has been realized. The spin‐coated samples present a single (111) out‐of‐plane orientation and very high crystallinity, which is comparable with previously reported epitaxial CuI thin films. The sputtered thin films have advantages in surface morphology and conductivity. Substituting S for I can achieve efficient acceptor doping of CuI for both the physical and chemical growth methods. The highest conductivity of CuI appears at 2.0 at% of S doping, and the doping efficiency is influenced by the self‐compensation effect. [ABSTRACT FROM AUTHOR]

An infrared transparent conductive material is a solution to realize the shielding function of infrared windows against electromagnetic waves, by combining the two characteristics of high transmission and conductivity in infrared wavelengths. Indium-hydroxide-doped (In2O3:H) thin films were prepared by atomic layer deposition method, which can achieve high IR transmission by reducing the carrier concentration on the basis of ensuring the electrical properties. On this basis, the effect of the post-deposition annealing process on the microstructure evolution and optoelectronic properties of In2O3:H thin films was investigated in this paper. It is demonstrated that the carrier mobility after annealing is up to 90 cm2/(V·s), and the transmittance at the 4 μm is about 70%, meanwhile, the carrier concentration after annealing in air atmosphere is reduced to 1019 cm−3, with a transmission rate of up to 83% at 4 μm. The simulations visualize the shielding performance of the annealed In2O3:H thin film against radar electromagnetic waves. It provides a guideline for fabricating lightweight, thin, and multi-functional shielding infrared transparent materials in the key fields of spacecraft and high precision electronics. [ABSTRACT FROM AUTHOR]

Infrared (IR) antireflective and protective coating (ARPC) is crucial for the development of IR precision guidance and detection systems for practical applications, attracting significant attention from strong military powers worldwide. Extreme application environments require functional film to have high surface hardness, excellent stability, and good adhesion. Further, multispectral optical transmission demands extremely low absorption in the visible and far‐IR bands, adjustability of optical performance parameters, and optical antireflection in particular bands, and radar stealth requires a relatively low resistance. Herein, recent experimental progress on IR ARPC is reviewed and future opportunities are discussed. Based on the application environment and window substrate, various ARPC material systems, including diamond‐like C, Ge carbide, B phosphide, and oxides, have been developed. These systems are capable of fulfilling different application demands and demonstrate exciting application prospects. To promote the development of IR ARPC material technology, the basic characteristics, fabrication techniques, microscale structures, optical properties, mechanical properties, and development and applications of typical IR ARPC materials from a comprehensive and systematic perspective are presented. [ABSTRACT FROM AUTHOR]

Mode coupling vibration of a multilayered ZnO thin film bulk acoustic wave resonator (FBAR) with its c-axis along the wave propagation direction operating at the fundamental thickness-shear (TSh) mode is studied in this paper. The accurate dispersion curve from 3-D piezoelectric theory indicates that the operating TSh mode could couple to the flexural mode, which influences the performance of a sensing resonator and needs to be eliminated through the so-called frequency spectrum analysis. Frequency spectra of coupling vibration in this FBAR can be obtained by substituting the displacement solutions consisting of the mode branches in the dispersion curve into several weak boundary conditions, which gives the integral boundary conditions across the plate thickness at the side edge of FBARs. The results show that the content of mode couplings to spurious modes depends on the plate length/thickness ratios. The character of desirable values of plate aspect ratios under which the operating TSh mode dominates among all modes is stated specifically, which provides fundamental guidance to the design of structural parameters of FBARs. [ABSTRACT FROM AUTHOR]

A novel plasma exposure technique has been introduced into conventional magnetron sputtering process to enhance the crystallization of indium oxide (InO) films at room temperature. The effect of plasma exposure technique with different pulsed DC voltages on the electrical and mechanical properties of InO films was investigated. It is observed that film crystallization can be significantly enhanced when the pulsed DC voltage (| V|) is higher than |−500 V| (| V| > |−500 V|). By applying the plasma exposure process, InO films prepared at room temperature with thickness of 135 nm shows low resistivity of 4.11 × 10 Ω cm, mobility of 42.1 cm/Vs, and transmittance over 80 % in the visible range. Compared with the InO films without plasma exposure process, the InO films with plasma exposure show better crystallization and remarkably higher nanohardness. The plasma exposure technique is a useful candidate technique for enhancing film crystallization at low temperature. [ABSTRACT FROM AUTHOR]

Abstract: A series of yttrium oxide films has been fabricated on Si (100) wafers by different substrate temperatures based on reactive magnetron sputtering technology. And the evolution of composition, microstructure and optical properties of Y2O3 films has been investigated by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and spectroscopic ellipsometry (SE). It is shown that stoichiometric Y2O3 with much strong Y O bond and cubic nanophase with larger size notably enhance the optical properties, especially refractive index. At low substrate temperature, the composition of Y2O3 films has nonstoichiometry feature accompanying with much physisorbed oxygen (Oδ) compared with these at high temperature. Increasing substrate temperature promotes the formation of Y O bonds, approaching the stoichiometry with lower Oδ content. The film commences crystallizing at room temperature, and transformation of crystalline phase from monoclinic to cubic occurs, along with preferred (111) orientation and large grain as temperature increases. The results facilitate clear relationship between the characterizations of Y2O3 film and growth parameters, also, it can be realized that adjustment of optical constants of Y2O3 films in a large range having the aid of substrate temperature to obtain desirable composition and structure for optical applications. [Copyright &y& Elsevier]

Transparent conducting oxide films are usually several 100-nm thick to achieve the required low sheet resistance. In this study, we show that the filtered cathodic arc technique produces high-quality low-cost ZnO:Al material for comparably smaller thicknesses than achieved by magnetron sputtering, making arc deposition a promising choice for applications requiring films less than 100-nm thick. A mean surface roughness less than 1 nm is observed for ZnO:Al films less than 100-nm thick, and 35-nm-thick ZnO:Al films exhibit Hall mobility of 28 cm2/Vs and a low resistivity of 6.5 × 10−4 Ωcm. Resistivity as low as 5.2 × 10−4 Ωcm and mobility as high as 43.5 cm2/Vs are obtained for 135-nm films. [ABSTRACT FROM PUBLISHER]

Abstract: In order to take the tetrahedral amorphous carbon (ta-C) films as the high acoustic impedence layer in a Bragg reflector isolating acoustic wave from the substrate in solidly mounted resonator, the multilayer films consisting of sp2-rich layers and sp3-rich layers were deposited from a filtered cathodic vacuum arc by adjusting the substrate bias. The microstructure of the films was evaluated using a visible Raman spectroscopy. The stress was calculated according to the changed curvature of the coated and bare substrate. The hardness, modulus and scratching were measured using a nanoindenter. It has been shown that the multilayer structure maintaining high tetrahedral content, high hardness and high elastic modulus is still characterized with lower intrinsic stress and better adhesion. [Copyright &y& Elsevier]

The interface between amorphous diamond films deposited by a filtered arc and germanium substrate was characterized by X-ray photoelectron spectroscopy. The coherent energy shifts of carbon and germanium photoelectron lines with prolonged etching time confirm the existence of an amorphous germanium carbide phase consisting of nonhomogeneous components in the interfacial region. This compound forms a buffer layer with a gradient of composition and microstructure from the substrate to the film and is beneficial to film adhesion. [Copyright &y& Elsevier]

Abstract: Boron doped tetrahedral amorphous carbon films, having boron content from 0.59 to 6.04at.%, have been prepared by a filtered cathodic vacuum arc system using boron mixed graphite targets. The influence of boron on the surface morphologies and microstructures of the films was studied by atomic force microscopy and Raman spectroscopy. The surface images showed that the irregular tops on the surface of the films tended to form larger clusters as boron content increased. The Raman spectra of the films were, respectively, deconvoluted using Gaussian and Breit–Wigner–Fano line shapes. The Raman parameters, including the intensity ratios, peak positions, peak widths and coupling coefficients, obtained from both line shapes were described and compared. It was found that both line shapes could produce consistent results except the peak widths of G bands. The major effect of boron introduction was to increase the clustering of the sp2 phase in the films. [Copyright &y& Elsevier]

Abstract: Tetrahedral amorphous carbon (ta-C) films were deposited by filtered cathodic vacuum arc technique with substrate negative bias setting in the range of 0–200 V. The film density, hardness and Young''s modulus were respectively obtained from the X-ray reflectivity and nanoindentation measurements. A maximum value of density was identified in the middle range of incident ion energy. Correlations between the density and elastic behavior of the films were then discussed theoretically based on the constraint-counting model of Philips and Thorpe. The measured Young''s modulus and hardness almost vary linearly with the increasing density which agrees quite well with the theoretic predictions. [Copyright &y& Elsevier]

This paper reports the evolutions of stress and mechanical properties of tetrahedral amorphous carbon films upon boron incorporation. A sharp stress relief and slight density reduction combined with moderate hardness and Young’s modulus were observed for the films with boron concentration up to 15% in the cathodes. Raman spectroscopy shows that a clustering of sp2 sites without a notable decrease in sp3 content occurs in the films, which is responsible for the mechanical behavior after boron incorporation. [Copyright &y& Elsevier]

Abstract: To reduce the stress of tetrahedral amorphous carbon (ta-C) films and improve the adhesion, a graded multilayer film was deposited using a filter cathodic vacuum arc (FCVA) deposition system. Nanoindentation measurement revealed the high hardness and Young''s modulus of the multilayer films. Nanoscratch test was used to estimate the scratching resistance of the multilayer films on Si substrate. The high critical scratch load implied the good cohesive and adhesive strengths of the graded multilayer films. [Copyright &y& Elsevier]

Abstract: To develop new infrared antireflective and protective coatings on the infrared band, amorphous diamond (a-D) films deposited by filtered cathodic vacuum arc (FCVA) technology have been investigated. The mechanical properties were characterized with the nano-indenter and the stress was calculated using Stoney''s equation. The optical properties were analysed with spectroscopic ellipsometry and the microstructure was investigated with EELS. The maximal hardness and Young''s modulus consorting with the highest stress are represented at the negative bias of 80 V. When the bias is increased or decreased, hardness, Young''s modulus and stress will descend gradually. However, the high impinging energy benefits the better adhesion and the lower stress. In the wide infrared band, the films are transparent. The optical gap and the refractive index exhibit the same changing regularities like hardness and stress, whereas the extinction coefficient demonstrates the reverse trace. The changing rules can be perfectly explained in light of the ratio of the different hybridization and the growth mechanism of the films. In short, a-D films deposited by the FCVA technology are superexcellent infrared protective coatings. [Copyright &y& Elsevier]

Highlights • Mode coupling vibration of thickness-extensional (TE) ZnO thin film resonator is studied based on exact dispersion curve. • Frequency spectra predicting the relation between coupling content and plate aspect ratios are obtained by using three different WBCs. • The desirable plate aspect ratios where TE mode weakly couples to spurious modes are located at the first flat area of frequency spectra. • Frequency spectra obtained by balance of high order stress are consistent with those obtained by Saint-Venant's principle quantitatively. • Frequency spectra firstly yielded by Hamilton principle give wider flat areas providing more structural parameter choices. Abstract In this paper, the mode coupling vibration of finite ZnO thin film resonator (FBAR) with its c-axis along the thickness direction operating at the thickness-extensional mode is studied. The dispersion curve of unbounded fully-electroded ZnO thin film indicates that the thickness-extensional mode couples to two unwanted spurious modes. Since the displacement solutions consisting of the sum of three mode branches in the dispersion curve have satisfied the differential equations and boundary conditions on the top and bottom surfaces exactly, the substitution of them into Hamilton principle as weak boundary condition (WBC) can give an integral boundary condition across plate thickness at the side edge of ZnO thin film resonator. Two other WBCs are also employed to study the same coupling problem to prove the validity of Hamilton principle. The frequency spectra obtained through all three WBCs indicate that the extent of mode couplings is sensitive to plate length/thickness ratios. The desirable values of plate aspect ratios where thickness-extensional mode weakly couples to two spurious modes are all located at the flat part of the obtained frequency spectra. Besides, the frequency spectra obtained through Hamilton principle include those obtained through other two WBCs because the mathematical expressions of Hamilton principle contain all terms in other two WBCs. The frequency spectra predicted by Hamilton principle have wider flat part than those from other WBCs providing more structural choices for device designers. These obtained results provide a significant guidance to the design and optimization of FBARs. Graphical abstract The above frequency spectra obtained through weak boundary conditions predict the relationship between the content of mode couplings and plate length/thickness ratio. The desirable values where the thickness-extensional mode dominates among considered vibration modes are located at the flat part of frequency spectra, which is preferred for good device performance. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the resputtering technique without separated ion sources was used to improve the crystallization of alumina films during preparation at low temperature using reactive magnetron sputtering. The effects of the novel resputtering technique on the microstructural, mechanical and optical properties of alumina films were investigated by atomic force microscopy (AFM), grazing incidence X-ray diffraction (GIXRD), nanohardness measurements and Ultra/visible spectrometer. The AFM diagram indicated that the low root-mean-square (rms) roughness values of alumina films increased from 0.8nm to 5.8nm by the resputtering technique. The GIXRD patterns showed that with the resputtering technique, alumina thin films transformed from the amorphous phase into crystalline phase. The nanohardness of the films increased from 13.6GPa to 15.6GPa by the resputtering technique, which was only slightly smaller than that of the crystalline alumina films subjected to a post-annealing at 950°C, about 16.6GPa. Additionally, the crystalline alumina films deposited with resputtering technique also display good optical properties with higher refractive index, as compared to the amorphous films. The results suggest that the reactive magnetron sputtering with the resputtering technique is a simple, cheap and effective method of preparing crystalline alumina films at low temperature. [Copyright &y& Elsevier]

Interface engineering has emerged as a fertile and efficacious approach to turn functional properties in the field of film systems. In this work, the interfacial properties of sputtered yttrium oxide films on zinc sulfide substrate (Y 2 O 3 /ZnS) were analyzed by transmission electron microscopy (TEM), X-ray photoelectron spectrum (XPS) depth profile and nano-scratch measurement. An interface layer with the depth of 20 nm between Y 2 O 3 film and ZnS substrate was directly observed by TEM. Under different film growth conditions, although the interfacial features including interfacial width and composition distribution exhibit similar behavior, it is found that higher cohesive strength is obtained under a special substrate bias voltage of −160 V at low substrate temperature. Such an enhanced mechanical property can be understood by the role of physisorbed oxygen in the interfacial region, in which less physisorbed oxygen with van der Waals bonds leads to a strong adhesion. Our results provide a favorable strategy to achieve strong adhesion between oxide and sulfide at low temperature, which are urgent in future micro-electric applications. [ABSTRACT FROM AUTHOR]

Highlights: [•] Y2O3:Ru (RYO) films were prepared on ZnS substrates by reactive magnetron sputtering. [•] Ru doping significantly decreases the resistivity and extends the transparent range. [•] Optical and electrical properties of RYO films can be tuned by substrate temperatures. [•] The RYO films exhibit excellent far-IR transmittance and electrical property. [ABSTRACT FROM AUTHOR]

Abstract: Indium doped cadmium oxide (CdO:In) films with different In concentrations were prepared on low-cost glass substrates by pulsed filtered cathodic arc deposition (PFCAD). It is shown that polycrystalline CdO:In films with smooth surface and dense structure are obtained. In-doping introduces extra electrons leading to remarkable improvements of electron mobility and conductivity, as well as improvement in the optical transmittance due to the Burstein–Moss effect. CdO:In films on glass substrates with thickness near 230nm show low resistivity of 7.23×10−5 Ωcm, high electron mobility of 142cm2/Vs, and mean transmittance over 80% from 500 to 1250nm (including the glass substrate). These high quality pulsed arc-grown CdO:In films are potentially suitable for high efficiency multi-junction solar cells that harvest a broad range of the solar spectrum. [Copyright &y& Elsevier]

• A new P-type transparent conductive LaSe 2 film with excellent photoelectric properties is found. • A novel two-step method is used to prepare LaSe 2 film. • Effect of annealing time on their photoelectric properties is investigated. • Results indicate that the best annealing time is 2 h. LaSe 2 films were prepared on sapphire (0001) substrates by combining magnetron sputtering and selenized annealing. The influence of selenized annealing time on the structures and photoelectric properties of the thin films were investigated using glancing incident X-ray diffraction, fourier transform infrared spectrometry and Hall effect measurements. The results showed that the film had a perfect monoclinic structure and a smooth surface morphology. The average transmittance in the mid-infrared range was greater than 55%, and the highest was 65%. The LaSe 2 films had a higher carrier concentration (∼1019 cm−3) and conductivity (∼1.9 S/cm) than those of other P-type transparent conductive films, which showed that LaSe 2 was a potential new P-type material. [ABSTRACT FROM AUTHOR]

Abstract As lanthanum oxide (La 2 O 3) has a large bandgap, it exhibits excellent optical properties. In this work, La 2 O 3 thin films are prepared by the sol-gel method from a lanthanum chloride (LaCl 3) precursor, on quartz and sapphire (0001) substrates. The effect of the annealing temperature (400–800 °C) on the optical properties of the La 2 O 3 films is investigated. The structure and optical properties are analyzed by X-ray diffraction, atomic force microscopy, scanning electronic microscopy, X-ray photoemission spectroscopy, Raman spectroscopy, ultraviolet (UV)–visible spectroscopy, Fourier transform infrared spectroscopy, and infrared variable angle spectroscopic ellipsometry. Results indicate that with an annealing temperature of ~600 °C, the roughness and optical properties of La 2 O 3 films can be significantly improved. Highlights • La 2 O 3 thin films are prepared by sol-gel method on quartz and sapphire substrates. • Effect of annealing temperature on their optical properties is investigated. • Results indicate that the best annealing temperature is around 600 °C. • The roughness and optical properties of films are significantly improved. [ABSTRACT FROM AUTHOR]

Abstract Transparent electronic technology has many urgent optoelectronic device applications. A key component of plasmonic materials in conventional semiconductors is the wide band gap of oxide thin films. Although transparent electronic materials have been developed for visible and near-infrared wavelengths, systems incorporating mid-infrared and far-infrared spectra are difficult to achieve. In this study, hydrated magnesium-carbon films, a new type of non-oxide transparent conductive thin films with a magnesium hydroxide structure, were generated using the three-step method. After annealing treatment, larger crystals in the thin films typically exhibited superior film resistivity, with conductivity values of approximately 8.63 × 10−3 Ω m. Due to the free electron concentration was not more than 1020 cm−3, the films demonstrated excellent optical properties, with plasma wavelength values of approximately 8 μm for infrared transmittance above 70%. After annealing, due to the Moss-Burstein (M-B) effect, the visible light transmittance was greater than 85% and the optical bandgap shifted towards the blue region. In addition, the influences of the sputtering power of the carbon target on the properties of hydrated magnesium-carbon film were also discussed in this paper. Graphical abstract Image 1 Highlights • We prepare hydrated magnesium-carbon films using the three-step method. • We analyze the effect of annealing on structural, electrical, and optical features. • Annealing leads to crystal growth, superior film resistivity, and good conductivity. • Films exhibit excellent optical properties, particularly for far-infrared ranges. • The films can replace TCO in the application of optical-electronic devices. [ABSTRACT FROM AUTHOR]

Abstract High-quality, transparent, conducting, p-type γ-CuI thin films are prepared via an innovative layer-by-layer procedure based on the traditional simple iodination of Cu films (referred to as the LBL-I method) at room temperature (RT). The structure, morphology, and optoelectronic properties of the γ-CuI are investigated as functions of the per layer thickness. The final thicknesses of LBL-I γ-CuI films are consistent with that in the film prepared by the traditional one-step method (TOS). X-ray diffraction analysis reveals that all the films are polycrystalline with the most dominant (111) direction of the zinc blende structure, indicating the facile and successful fabrication of γ-CuI. Compared with the TOS film, the LBL-I films display enhanced transmittance and mobility. The higher transmittance of >80% in the visible region of LBL-I films was attained due to the smaller root-mean-square roughness values of 23–28 nm. The 50 nm/ l LBL-I CuI films have mobility values of 6.9–9.4 cm2 V−1 s−1, and lower resistivity of 0.039–0.05 Ω cm, which assist studies on applications of γ-CuI thin films in transparent electronics. Highlights • High-quality electrooptical properties p-type γ-CuI thin films are prepared. • Innovative layer-by-layer approach based on Cu films iodination (LBL-I) is used. • LBL-I films show better transmittance and mobility than films prepared in one step. [ABSTRACT FROM AUTHOR]

Abstract In p-type γ -CuI thin films synthesized by the iodination of Cu layers with iodine vapor, a frosted-glass-like appearance with a rough surface is usually obtained, which makes it difficult to apply the γ -CuI films to transparent electronics. This paper proposes an innovative method for the preparation of highly transparent p-type γ -CuI films. A chemical reaction between Cu thin films and iodine vapor, combined with the layer-by-layer process at a temperature between room temperature and 120 °C are found to result in highly transparent polycrystalline γ -CuI films. The root-mean-square roughness values of the γ -CuI films prepared by this method are 8.5–21.2 nm, which are smaller than those for the γ - CuI films synthesized by the conventional method. The microstructure and optoelectronic properties of the γ-CuI thin films are sensitive to the temperature of iodine vapor. A high transmittance (80%) of the film obtained at an iodine vapor temperature of 80 °C has a low resistivity of 5 × 10−2 Ω cm and high mobility of 8.7 cm2/Vs. Moreover, a boosted figure of merit is realized due to the simultaneously low resistivity and high transparency: its value jumps from ∼488 to ∼1630 MΩ−1. Graphical abstract Unlabelled Image Highlights • A traditional iodination reaction method combined with the layer-by-layer process. • Simultaneously high transmittance and low resistivity. • A boosted figure of merit is realized. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A novel two-step method is developed to grow 2D Mg(OH) 2 nanoflakes. • The proposed method is environmentally benign. • The method does not require catalysts or harsh acid-base conditions. • The Mg(OH) 2 films had a crystalline hexagonal structure is dominant. • The water contact angle of 139° showed the good hydrophobicity of the film. Abstract A novel and environmentally benign two-step method has been developed to grow 2D magnesium hydroxide (Mg(OH) 2) nanoflakes. Our method relies on the deposition of Mg films by magnetron sputtering, followed by reaction with water vapor, and does not require any catalyst or harsh acid-base conditions. The 2D nanoflake surface morphology with a crystalline hexagonal structure was dominant on the Mg(OH) 2 films. The water contact angle on the film was ∼139°, which testified the good hydrophobicity of Mg(OH) 2 films due to the nanoflake surface. The self-cleaning effect of contaminant particles on hydrophobic Mg(OH) 2 films was analyzed. Compared with other preparation methods, this two-step method is more efficient, cleaner, and simpler, which make it suitable for complex or large-area substrate surfaces. In addition, this method can be applied to other metal hydroxides or oxides. [ABSTRACT FROM AUTHOR]

The hydrated magnesium-carbon films fabricated in this study are the novel-innovative non-oxide-type transparent electronic material. The films, which have a structure similar to that of magnesium hydroxide, were produced by making Mg x -C y films deposited by magnetron co-sputtering react with water vapor. As the extrinsic defect of hydration magnesium-carbon films, C atoms provided redundant electrons, resulting in a conductivity of approximately 3.31 × 10 −2  Ω·cm. Although the conductivity of hydrated magnesium-carbon films is not prominent comparing to the conventional and widely-used n-type TCO materials, e.g. ITO, the films also showed excellent optical properties, which can be attributed to their low bond energy, with the infrared transmittance of the films being greater than 72% for a plasma wavelength of approximately 10 μm. By varying the atomic C content of the films, a visible-region transmittance greater than 80% could be realized. The optical bandgap of the films was approximately 4.04–6.87 eV and was blue-shifted because of the Moss-Burstein effect. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of deposition conditions on the properties of yttrium oxide thin films. The paper focuses on the texture, optical and mechanical properties. With this objective, a series of yttrium oxide thin films with different thicknesses were deposited by direct current (DC) unbalanced reactive magnetron sputtering at high and low pumping speed. By changing the oxygen flow, depositions were performed in the three characteristic deposition modes for reactive magnetron sputtering, i.e., metallic, transition and poisoned mode. By using an oxygen flow directed to the substrate, full oxidation of the samples, as shown by X-ray photoelectron spectroscopy (XPS), in the three modes is obtained. Crystallographic characterization by X-ray diffraction (XRD) shows that films crystallize in the cubic phase with a strong (222) out-of-plane orientation at low oxygen flow. As the oxygen flow increases a mixture of cubic and monoclinic phase is obtained. In poisoned mode, the films consist of the cubic phase with preferred (420) orientation. Scanning electron microscopy (SEM) cross sections show, with increasing oxygen flow, a loss of the columnar structure. As the oxygen flow rates increase through the metallic, transition, and the poisoned mode, the grain size becomes gradually smaller. An overview diagram of all experimental results uncovers that the textural changes are closely linked to the oxygen partial pressure rather than the oxygen flow. The optical properties of films were investigated by spectroscopic ellipsometry (SE). The films with a columnar structure demonstrate superior hardness and modulus as well as the high plasticity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly crystalline In 2 O 3 films are grown by pulsed reactive magnetron sputtering. • Substrate heating further improves the film crystallinity and conductivity. • 400 °C is the limit for benefiting to obtain the optimum crystallinity of In 2 O 3 films. • The films deposited at 400 °C yield the lowest resistivity of 1.28 × 10-4 Ω⋅cm. • An average transmittance of greater than 80% are also obtained at 400 °C. A transparent conductive oxide (TCO) should have a combination of high electrical conductivity and optical transmission property to fulfill the challenging demands of industrial applications. So far, doped TCOs have been mostly considered to fulfill the technological challenges. In this study, we demonstrate that indium oxide (In 2 O 3) thin films without intentional doping can be deposited with high crystallinity under specific film growth conditions leading to thin films with high mobility, high electrical conductivity, and high transmittance. In 2 O 3 thin films have been deposited by reactive pulsed direct current magnetron sputtering (pulsed DCMS) from an indium target on substrates in a temperature range from room temperature (RT) to 600 °C. Detailed investigations on In 2 O 3 thin films are performed and the film properties such as crystallinity, microstructure, chemical bonding states, electrical and optical properties are revealed. Enhanced plasma density and ionization degree provided by the employed reactive pulsed DCMS and the intentional substrate heating during the thin film deposition give possibility to deposit highly crystalline thin films which are preferentially oriented in (2 2 2) direction. The substrate heating enhances the crystallinity of the grown films up to a certain optimum temperature: 400 °C. When the substrate temperature is above 400 °C, the carrier concentration and mobility decrease due to the grain refinement effect caused by growth competition of grains in different orientations. The films grown at 400 °C indicate the presence of high oxygen vacancy concentrations, which can directly be associated with a high charge carrier concentration despite the lack of intentional doping. The undoped In 2 O 3 films in this study grown at 400 °C show highly promising and competitive electrical properties such as low resistivity of 1.28 × 10-4 Ω⋅cm and the high carrier mobility of 69 cm2/Vs. The average transmittance of the In 2 O 3 films with the highest conductivity is found to be greater than 80% in the visible to the near-infrared spectral region owing to an enhancement in the carrier mobility and an optical bandgap in the range from 3.61 eV to 3.77 eV. [ABSTRACT FROM AUTHOR]

Abstract: Ultra-thin tetrahedral amorphous carbon (ta-C) films have been prepared by filtered catholic vacuum arc system for recording slider applications. In order to study the corrosion behavior of the slider coatings deposited at different substrate bias, the micro-structure and surface properties of the ta-C films were respectively investigated in terms of Raman spectroscopy, atomic force microscopy, water contact angle and corrosion measurements. Results showed that a very smooth ta-C film with lowest surface energy and highest sp3 bonding content was obtained at the medium bias voltage of 100 V. However, as to the protection against corrosion, the optimum bias was found to be greater than that giving the maximum diamond-like properties. [Copyright &y& Elsevier]

Vanadium pentoxide (V 2 O 5) films were deposited on sapphire substrates by radio frequency (R.F.) magnetron sputtering at 450 °C and annealed in various ambient atmospheres. The influence of ambient atmospheres on the structure, optical properties, and morphology of the thin films after annealing were characterized, and the transition behaviors in the annealing process were investigated by DSC, temperature-dependent Raman and FTIR. The results demonstrated that V 2 O 5 films underwent four different transition behaviors during post-deposition annealing due to the different oxygen proportion of ambient. Different products (VO 2 (B), VO 2 (R)) in the transition process were the main reason for the evolution of optical properties. No transition behaviors occurred because of the oxygen-rich ambient when annealed in air, and no significant change in infrared transmittance was observed. When annealed in 0.1% O 2 /Ar, the film was converted to VO 2 (B) with the decrease of infrared transmittance. In the case of 0.01% O 2 /Ar, metastable VO 2 (B) and VO 2 (R) were observed as intermediate crystalline phases before V 2 O 5 finally transformed to VO 2 (M), and the changes in the three stages of two drops and one rise were shown in infrared transmittance. While annealed in pure argon ambient, V 2 O 5 was turned into VO 2 (R) and VO 2 (M) without VO 2 (B) phase production, accompanied by a single change of infrared transmittance reduction and recovery. This provides a more detailed vanadium oxide thermal transition process and shows data reference for the preparation technology and application of vanadium oxide materials. • V 2 O 5 films were deposited on sapphire substrates by radio frequency (R.F.) magnetron sputtering; • Effect of the different oxygen proportion during annealing on thermal transition behaviors was investigated in detail by temperature-dependent Raman and FTIR; • The annealed V 2 O 5 films were transformed into V 2 O 5 , VO 2 (B), and VO 2 (M) by different thermal transition behaviors; • VO 2 (M) films with excellent thermochromic properties can be obtained by controlling the annealing atmosphere and temperature. [ABSTRACT FROM AUTHOR]

• AZO/Ag/AZO multilayer films are prone to failures under thermal oxidation. • Inserting Ni layer can improve the photoelectric stability of AZO/Ag/AZO films. • Film had good transmittance, surface resistance and structure after oxidation at 500 °C. • Ag diffusion was inhibited by Ni layer and photoelectric stability was improved. Dielectric/metal/dielectric-structured transparent conductive films are prone to structural and functional failures under thermal oxidation environment. Herein, a Ni layer was employed to improve the photoelectric stability of AZO/Ag/AZO multilayer films. The AZO/Ni/Ag/AZO film exhibited a transmittance of 75%, surface resistance of ~7 Ω/sq, and stable structure after thermal oxidation treatment at 500 °C. The visible light transmittance, surface resistance, and figure of merit values of the AZO/Ag/AZO and AZO/Ni/Ag/AZO films were determined after high-temperature treatment in ambient air. The diffusion of Ag was effectively inhibited by the Ni layer, and the photoelectric stability of AZO/Ag/AZO films was improved under thermal environment. [ABSTRACT FROM AUTHOR]

The performance of atomic layer deposition films is mainly limited by precursor residues, low crystallinity and densities due to low deposition temperatures. Here, we used atomic layer deposition to deposit tin oxide thin films at a relatively low temperature of 250 °C. At this temperature, the change in the valence of Sn due to precursor residue is eliminated by layer-by-layer Ar plasma treatment, and the crystallinity of the films is improved. The effects of Ar plasma treatment power and Ar treatment time on the structural and optoelectronic properties were investigated. It was found that Ar plasma treatment time more significantly affects the surface morphology and the optical and electrical properties of the film. The film is transparent to both visible and near-infrared light over a wide range of wavelengths from 400 nm to at least 5000 nm. The film resistivity can be as low as 1.117 × 10−3 Ω·cm. The film has a relatively low level of residual stress due to the fact that there is no need to improve the crystallinity of the film by conventional high temperature annealing. On the basis of the high transparency and high conductivity of the SnOx films with layer by layer Ar plasma treatment in situ, the films can be applied as electromagnetic shielding windows for photodetectors. Unlabelled Image • The films exhibit excellent crystallinity and conductivity without the need for a high-temperature annealing step. • Ar plasma treatment significantly reduced the proportion of reduced Sn4+. • The plasma treatment time has a more pronounced effect on the SnOx crystallinity than the treatment power. • Designed and prepared an infrared transparent conductive film with excellent electrical properties and optical transmission [ABSTRACT FROM AUTHOR]

• A self-powered vertical heterojunction photodetector based on n-SnOx/p-diamond was fabricated by RF sputtering. • The device has a peak response at 350 nm and responds to light wavelength in the 250–500 nm range at zero bias. • Analysis of the detection mechanism of the n-SnOx/p-diamond heterojunction photodetector. High-performance self-powered UV-blue photodetector was fabricated based on n-SnO x /p-diamond heterojunction. The SnO x film was deposited on the high temperature and high pressure synthetic boron doped diamond wafer by RF magnetron sputtering. This heterojunction device exhibits a good rectification behavior with a rectification ratio of 3.15 × 104 at ±3 V. At zero bias, the device responds in the wavelength ranging from 250 nm to 500 nm with a peak response at 350 nm. The photoresponse rise time and decay time of the device are both less than 2 s under UV-blue illumination with different wavelengths. These results demonstrate that the n-SnO x /p-diamond heterojunction device has potential applications in the field of UV-blue detection. [ABSTRACT FROM AUTHOR]