Physical Vapor Deposition Method Research Articles

SYNTHESIS AND INVESTIGATION OF STRUCTURAL, SURFACE MORPHOLOGICAL AND OPTICAL PROPERTIES OF InSe/PMItz HYBRID HETEROJUNCTION

On a series of annealed and unannealed InSe thin films which were formerly produced by electrochemical deposition method, organic PMItz semiconductor compound was growth by physical vapour deposition (PVD) method. Structural analyses of the films carried out by X-ray diffractometry (XRD) method revealed that glass/ITO/InSe film formed in hexagonal InSe phase while glass/ITO/InSe(annealed) film formed in monoclinic In6Se7 and orthorombic In4Se3 phases. Surface analyses of the layers forming heterojunction were conducted by atomic force microscoby (AFM) and it is observed that the layers are homogenous and have different roughness values. Optical analyses of the films demonstrated that annealing of the film result with increased absorption coefficient and reduced energy band gap. Moreover, other optical parameters of the films i.e. refractive indice(n), extinction coefficient (k), real dielectric constant(Er), imaginary dielectric constant(Ei) and optical conductivity were determined and compared within 300-1000 nm range.

INVESTIGATION OF THE EFFECT OF NANOCOATINGS ON THE WEAR-RESISTANCE OF SOCKET CARBIDE MILLS

The results of studies of the wear-resistance of socket mills made of hard alloys in the processing of hard-to-process structural chromium steels are presented. The technology of hardening of cutting teeth with a wear-resistant coating obtained by the Physical Vapour Deposition method is considered. The influenceof the structure of the hardening composite coating based on titanium nitrides and carbonitrides on the mechanical characteristics and working capacity of the tool is shown. The nature of wear and brittle destruction of the working surfaces of the tool under intermittent cutting conditions and the influence of wear-resistant coatings on the thermal and stress state of the cutting wedge in the contact zone are investigated.

Indirect Production of Chromium Carbides Film on Low Alloy Steel

Chromium carbide coatings deposited on mechanical parts by different techniques have an interesting hardness, wear-resistant and corrosion resistance. Some studies show that chromium carbides produced by physical vapor deposition methods and revealed a superior hardness present a poor adherence to their substrates. The objective of this study is to indirectly obtain a hard, and adherent coating of chromium carbide by using a conversion treatment including carburizing treatment of steel substrate, deposition of a pure chromium layer, and annealing treatment of coated carburized steel under a carbonic gas atmosphere. Treatment temperature has an effect on the partial or complete conversion of chromium film as a result of the diffusion and precipitation process. The transformation rate of chromium into both chromium carbide layers was investigated. For 1 h of holding treatment, chromium film was totally transformed at 900 °C into chromium carbide film which presented high hardness and excellent adhesion.

Room-Temperature Excitonic Nanolaser Array with Directly Grown Monolayer WS2

Two-dimensional (2D) transition-metal chalcogenides (TMDCs) with strong excitonic emission are ideal candidates for small-volume gain materials in nanolasers, which can be realized by integrating 2D TMDCs with optical microcavities. However, at present, the integration is usually realized by the transfer method, which is not suitable for large-scale production, and the quality factor of the microcavity usually drops sharply in the process of transfer. Therefore, scalable fabrication of nanolasers remains an urgent issue to be solved. In this paper, by embedding continuous monolayer WS2 between silicon nitride (Si3N4) microdisks and Al2O3, we demonstrated the room-temperature transfer-free excitonic nanolaser array. Lasing at room temperature is achieved with the help of the high-quality-factor Si3N4 microdisks and the physical vapor deposition method for growing 2D gain material directly. This work provides a practical solution for large-scale and low-cost TMDC-based nanolaser arrays in the integrated optical communication systems.

Effect of the metallization method on properties of hybrid zirconia/Ti–6Al–4V joints

The addition of titanium powder and physical vapor deposition of titanium were applied for metallization of zirconia surface. The hybrid members of stabilized ZrO2/Ti–6Al–4V were fabricated using the Ag–28Cu filler metal. Different phases including TiCu3, Ti3Cu3O, Ti2Cu, and Ti6O were observed in the microstructure of joints. The sound joints were obtained when physical vapor deposition method was used for metallization; while various defects were observed after addition of the metallic powder to the joint. The increased thickness of filler metal or the metallized layer of zirconia promoted formation of the interaction layer between ceramic and filler metal. The formation of Ti3Cu3O along the joint interface encouraged the brittle fracture and decreased strength of the dissimilar joint. The maximum shear strength of the joint was obtained for the specimen which was metallized for 6 min by the physical vapor deposition method and was joined using the 50 μm thick filler metal.

Morphology and optical properties of CdS thin films prepared by Physical Vapor Deposition method

The optical properties of cadmium sulfide thin films obtained by thermal evaporation in vacuum were studied. The stoichiometric compositions of the binary compound previously synthesized from high-purity powders of the initial components were used. Films of different thicknesses deposited on a glass substrate were investigated using scanning electron microscopy and absorption coefficient was defined by the Swanepoel method. It was found that with increasing film thickness, surface formations decrease and at a thickness of 1 μm the film surface is continuous. It is determined that thin films of cadmium sulfide have optimal optical parameters for use as photovoltaic buffer layer. All the obtained films except the film with a thickness of 1215 nm show the usual interference pattern in the reflection spectra.

Controlled Growth and Chemical Engineering of FeSe‐Based Superconducting Films

AbstractChemical engineering tailors functional materials to meet the demands of physical and chemical properties, accelerating materials discovery and design in a multidisciplinary field. However, stereotyped synthetic paradigms in physical and chemical approaches obstruct the effective integration of multiple advantages of respective materials exploration methods. Solid state reaction is often considered separately with wet chemistry synthesis route, such as film growth using physical vapor deposition and hydrothermal methods. Here, the controlled growth of FeSe thin films by physical deposition techniques followed by the chemical engineering to create heterogenous interface in FeSe films via a solution‐based environment is demonstrated. The two‐step route allows an expanded crystal structure and enhanced superconducting transition temperature from 3.6 to 38 K, providing a new strategy to design functional hybrid materials.

Tunable polarized terahertz wave generation induced by spontaneous polarization-dependent ultrafast shift current from vertically grown ferroelectric SnS

Ferroelectric group-IV monochalcogenides $MX$ ($M=\mathrm{Sn}/\mathrm{Ge}$ and $X=\mathrm{S}/\mathrm{Se}$) are of particular importance for the new-generation photovoltaic devices due to their special in-plane spontaneous polarization resulting in a bulk photovoltaic effect. However, the spontaneous polarization and its related dynamical photoresponse under an ultrafast laser excitation are rarely studied via a noncontact all-optical method. Herein, the vertically grown SnS nanosheets have been synthesized by a physical vapor deposition (PVD) method and the corresponding spontaneous polarization is characterized via the terahertz (THz) emission spectroscopy. The primary THz emission mechanism is ascribed to the shift current, which is proved by the THz wave dependences on the pump light polarization angle and pump fluence. Interestingly, the shift current depends on the spontaneous polarization along the SnS nanosheet grown direction, according to the reversed polarity of the THz wave under opposite directional excitations. Furthermore, the amplitude and phase of the THz wave are modulated by the pump light polarization angle, resulting in the elliptical THz wave emission with tunable ellipticity and orientation angle. Our study has shed light on the shift current of ferroelectrics and controllable polarized THz wave generation, which provides application prospects for ferroelectric-based photovoltaics, nonlinear photonics, and THz polarized devices.

Infrared Analysis and Effect of Nitrogen and Nitrous Oxide on the Glass Transition of Methanol Cryofilms.

Methanol plays an important role in studying the structure and dynamics of hydrogen bonds in alcohols and other physiologically important compounds in the condensed state. The physical vapor deposition method and two-beam interferometry make it possible to study the structure of polyatomic molecules, the nature and character of intermolecular interactions, and the internal structure of various compounds. Thus, it becomes possible to analyze changes in the internal structure of substances near the points of their phase transitions and glass transitions at ultralow temperatures. In this work, we have studied the effect of nitrogen and nitrous oxide on the dependence of refractive indices of methanol on temperature and on structural-phase transformations upon heating from 16 to 160 K.

Facile engineering of gold alloying on the constancy of silver with polytetrafluorethylene denture base nanomaterial for antimicrobial investigation

Herein, nanocomposites comprising Ag–Au-alloy-based nanomaterials ensembled on the polytetrafluoroethylene (PTFE) were fabricated using the physical vapor deposition method. The Ag-based nanomaterials (AgNMs) undergo oxidation and dissolution in water; therefore, changes in the shape, optical characteristics, and composition of the nanocomposites were investigated through transmission electron microscopy, ultraviolet-visible spectroscopy, and X-ray photoelectron spectroscopy. PTFE@Ag–Au coatings exhibited high antibiofilm efficacy against E. coli WT F1693 and governed the synergistic effect of antibacterial non-stick PTFE and the Ag–Au alloy. The PTFE@Ag–Au-coated NMs sustained the release of Ag+ ions and inhibited up to 50% bacterial growth after 7 days in relation to the PTFE-coated NMs. The conventional XDLVO and DLVO theories were used to describe bacterial adhesion and understand the anti-adhesion process. Despite concerns associated with the hazardous effect of excessive Ag release on fibroblast cells, the coating methods precisely controlled Ag loading, thereby reducing metallic-implant-related bacterial infections.

Facile fabrication of multifunctional transparent electrodes via spray deposition of indium-tin-oxide nanoparticles

Low-dimensional nanomaterials with various functionalities are highly promising materials for transparent electrodes which are key components of electronic and optoelectronic devices. However, conventional physical vapor deposition (PVD) methods are not applicable to low-dimensional nanomaterials because of the harsh vaporizing conditions, and using solution processing technologies as alternatives is attracting attention. Herein, we demonstrate a facile method for fabricating of multifunctional transparent electrodes via one-step spray deposition of indium-tin-oxide (ITO) nanoparticles. In this method, ITO nanoparticles are spontaneously and rapidly packed, forming electrically conductive thin films composed of random nanostructures. This method can be adapted to fabricating hierarchical structures, that is, micropatterns consisting of random nanostructures, using impermeable shadow masks. In addition, the optical and electrochemical properties of the spray-deposited ITO films were investigated to confirm their high transmission haze values and ion-storage capabilities, leading to further applications such as random scattering layers, transparent superconductors, and high-performance electrochromic devices. We expect these results to spur the development and refinement of multifunctional electrodes and their electronic and optoelectronic applications.

Solar and infrared light sensing comparison of Yb/CIGS photodiode

Glass/Mo/CIGS/Yb Schottky photodiodes were fabricated by the physical vapor deposition method. The structural and morphological characterization of the CIGS layer on Mo was carried out. The current-voltage ( I-V ) characteristics were investigated in the dark, under solar light, and infrared. The diodes' ideality factor and zero bias barrier height were calculated as 1.55 and 0.84 eV in the dark, respectively. When the time-dependent current plots are examined, it is seen that the rise and decay times are lower for solar light than infrared. As the intensity of solar light increases, the rise and decay times decrease. The responsivity value for 100 mW/cm 2 solar light was found to be 8.5 mA/W and the detectivity value was 1.7 × 10 7 Jones. For infrared light, the same parameters were calculated as 3.4 mA/W and 7.1 × 10 6 Jones. Furthermore, capacitance-voltage and conductance-voltage characteristics were evaluated for different frequencies. • Yb/CIGS photosensor was produced on bi-layer Mo layer. • Switch ON−OFF time was maintained at 5 s • I-t and C-t measurements taken at different solar light intesities (from 20 to 100 mW/cm 2 ) and infrared (100 mW/cm 2 ). • Responsivity and detectivity parameters were calculated. • Frequency−dependent C-V and G-V characteristics investigated.

A novel nanoporous Mg-Li material for efficient hydrogen generation

• Nanoporous Mg-Li material is successfully prepared for the first time. • This material can deliver 962 ml g −1 H 2 in 15 min at 0 °C and in 3 min at 50 °C. • The advances come from the nanoporous structure and the addition of li element. • The growth mechanism of the nanoporous Mg-Li material is proposed. Hydrogen generation material is a new kind of energy material that can supply hydrogen by reacting with water and is drawing more and more attention with the development of hydrogen economy. In this study, a novel nanoporous magnesium-lithium material prepared by a physical vapor deposition method exhibits an excellent hydrogen generation property. It generates hydrogen efficiently and quickly with saltwater, reaching a hydrogen generation amount of 962 mL g −1 and hydrogen generation rates of 60 mL g −1 min −1 , 109 mL g −1 min −1 , 256 mL g −1 min −1 and 367 mL g −1 min −1 at 0 °C, 25 °C, 35 °C and 50 °C, respectively. The nanoporous magnesium-lithium material is composed of a solid solution phase with a magnesium-lithium atomic ratio of 17:3. By synchrotron radiation analysis, the sizes of the nanopores are in the range of 100 nm ∼ 600 nm with an average size of 280 nm, and the porosity is calculated to be ∼42.4%. The improved hydrogen generation property is attributed to the nanoporous structure with a high specific surface area, and the addition of lithium element which acts as active sites in hydrogen generation process.

Growth mechanism of nano-plates structured SnS films on different substrates in glancing angle deposition method

In this work, Tin (II) sulfide films have been deposited on glass, Indium Tin Oxide, and Fluorinated Tin Oxide substrates at the deposition angles of 0º, 65º, and 85º using Physical Vapor Deposition method equipped with Glancing Angle Deposition technique. Based on the results obtained from the X-ray diffraction technique, the crystalline structure of substrates and the angle of depositions along with their effects on the structure of SnS nano-plates have been investigated. Using Raman analysis, the phonons lifetime of the samples was found to change with the type of substrate and the employed deposition angle. Based Energy-dispersive X-ray spectroscopy analysis, the atomic ratio of Sn to S was observed to change with the change of deposition angle, substrate type and variation the diameter of nano-plates. This phenomenon resulted the formation of the second phase of Sn2S3 which was confirmed by Raman and X-ray diffraction patterns. The nano-sheets-like growth of all the samples has been confirmed using Felid Emission Scanning Electron Microscopy analysis. For further morphological studies, the Atomic Force Microscopy analysis has been applied, by which the direct relation between the substrate roughness and the final structure of the samples has been observed. The relation between the substrate roughness and the deposition angle in the growth process of SnS nano-sheets has been explained.

Analysis of TihxOy Films Produced by Physical Vapor Deposition Method

For decades, partially oxidized hydrides were commonly considered as undesirably contaminated phases and were avoided by scientists. Nevertheless, more recently, it was realized that in some hydrides and oxides, partial substitution of dissimilar H− and O2− anions allows one to obtain unique optical and electrical properties that might have appealing applications in commercial products. It was determined that specific properties of so called oxyhydride materials strongly depend on the used synthesis methods; therefore, there is a great interest in exploring various variants of oxyhydride formation. In the current study, TiHxOy films were deposited by a reactive magnetron sputtering process in Ar-O2-H2 gas mixtures. Color, transparency and crystal phase composition of the films coherently reacted to the Ar:O2:H2 gas ratio. Namely, the rise in partial hydrogen pressure promoted the formation of anatase phase TiO2 structure and darkening of the films. Interestingly, this had only minimal impact on the band gap values, but had a relatively strong negative effect on the photocatalytic activity of the films. The unaccustomed results stressed the difference between the partially reduced TiO2 with a significant amount of oxygen vacancies and synthesized TiHxOy films where some O2− ions are implicitly substituted by H− ions.

Optical Studies of Thin Films of Cryocondensed Mixtures of Water and Admixture of Nitrogen and Argon.

The interaction of host molecules with water molecules is of primary importance in astrophysical and atmospheric studies. Water-binding interactions continue to attract a broad interest in various fields, especially those related to the formation of assembly structures. Using the physical vapor deposition (PVD) method and a two-beam interferometer with a wavelength of 406 nm, the refractive indices of thin films of a water and nitrogen (argon) mixture were calculated in the range from 15 to 35 K. The results of temperature transformations of the obtained films from a two-beam interferometer, and thermal desorption characteristics from the temperature of condensation to the temperature of evaporation of water (15-180 K), are presented. The relationship between the signal of the interferometer, the refractive index, and the film thickness during glass transition is demonstrated.

Tailoring biodegration rate of AZ31 magnesium alloy

The biocorrosion phenomenon is an important mechanism that determines the biodegradability capacity. The effectiveness of studies on biodegradable materials is directly proportional to detailed corrosion experiments and analysis of formation mechanisms. In this context, experiments and analyzes have also become frequently used for magnesium alloys. In this study, TiN-based coatings were applied by physical vapor deposition method to tailor AZ31 alloy suitable for use as temporary implant material. Different in vitro media were used for comprehensive simulation of the biological environment, and material losses were interpreted on the basis of corrosive damage.

Surface Engineering of Woodworking Tools, a Review

The wide range of applications of wood are due to its strength properties. The mechanical properties of wood in various parts or directions are different. The complex structure of wood and its hygroscopicity prevent the use of coolants and lubricants, resulting in rapid tool wear disproportionate to the hardness of the processed material. This significantly affects machining efficiency and the quality of the processed surface. It seems that an effective method of reducing tool wear is its modification with a thin hard coating produced by the Physical Vapor Deposition or Chemical Vapor Deposition methods. The article presents tool materials used for woodworking, areas for improving the efficiency of their work, and the impact of thin hard coatings on the increase in tool durability, including binary coatings and also doping with various elements and multilayer coatings. Scientific centers dealing with the above-mentioned subject are also mentioned. A brief review of the effects of surface modifications of woodworking tools in the context of their durability is presented. It was found that the most promising coatings on tools for woodworking were multilayer coatings, especially based on chromium. Higher wear resistance was demonstrated by coatings with a lower coefficient of friction. This value was more important than hardness in predicting the service life of the coated tool.

Thermogravimetric study of 316L steel coated by physical deposit in vapor deposition phase (PVD)

Catastrophic carburization (metal dusting) is one of the problems with the greatest impact on the petrochemical and direct iron reduction industry. This work shows the synthesis of chromium oxide (Cr2O3) coatings on 316L steel as a protective layer to prevent and/or delay material degradation. In this work, the Physical Vapor Deposition (PVD) method will be used, since it is a technique that allows the control of the atmosphere in which the deposition is being carried out, forming high quality thin films, with excellent adherence to the substrate, thus improving its surface properties. Thin films with thicknesses less than one micrometer were obtained, which were subjected to corrosion tests by thermogravimetry in an atmosphere of CH4 at 800°C for 15 minutes and 20 hours, scanning electron microscopy and elemental quantification. The coatings obtained showed an improvement in their resistance to corrosion in critical atmospheric conditions according to the graphs obtained in the thermogravimetry test, observing a lower weight gain compared to the uncoated sample.

(Digital Presentation) Preparation of Metal Halide Perovskite Thin Films Via Laser Deposition

We have been preparing metal halide perovskite (hereinafter referred to as perovskite) thin films by laser deposition. In this study, we report the results of our investigation of the effects of laser wavelength and fluence on the deposition process. One of the most important features of perovskites, which have been rapidly developed in recent years as materials for high-efficiency and low-cost thin-film solar cells, is the applicability of a simple process using solution coating under atmospheric pressure [1]. Crystal growth of perovskite by the solution method occurs through equilibrium chemical reactions, enabling the formation of thin films on the order of μm thickness in less than a few seconds; however, it is difficult to systematically control the crystal growth process at the molecular layer level by the solution method. On the other hand, in the physical vapor deposition (PVD) method, although the deposition rate is relatively low, ranging from sub-nanometer to several nm/s, the deposition can be controlled at the molecular layer level, as well as allowing different atoms to be readily introduced into the film. Therefore, the PVD method allows the addition of elements that are difficult to achieve with solution reactions and is suitable for studies that investigate the effects of such elements on physical properties.In laser deposition (LD), one of the PVD methods, materials are irradiated with an infrared (IR) or an ultraviolet (UV) laser beam, and thin films are formed by evaporation through IR heating or ablation with plasma formation through UV electron excitation. The advantage of LD is that it can cause instantaneous heating or ablation by switching on and off laser irradiation only on the material surface, thus enabling the deposition of molecular layers of organic materials with high vapor pressure or high melting point materials such as inorganic oxides with minimal cross-contamination caused by evaporation. We have prepared perovskite thin films by alternate deposition of PbI2 and CH3NH3I (MAI) using an IR laser and solid-phase reaction at room temperature aiming at the detailed investigation of the crystal growth process and introduction of various dopants in perovskite materials. [2, 3]. In this study, we have also performed perovskite film deposition by UV pulsed laser and investigated the difference in the physical properties of the perovskite films compared to those deposited by IR laser.Fig. 1 shows a schematic structure and appearance of the laser deposition system used in this experiment. The experimental method is described below. A synthetic quartz substrate was introduced into an ultra-high vacuum chamber with a base vacuum of 2×10-5 Pa., Then a semiconductor continuous IR laser (wavelength: 808 nm) or a UV pulse laser beam generated by the fourth harmonic of an Nd:YAG Q-Switch laser (wavelength: 266 nm, 10 Hz) was irradiated alternately onto PbI2 and MAI targets to form CH3NH3PbI3.The optical band gap of the thin films deposited by continuous infrared laser deposition shows a change in optical band gap depending on the thickness of the alternately deposited PbI2 and MAI, which can be attributed to the different content ratios of the tetragonal and orthorhombic phases. Interestingly, in UV pulsed laser deposition, the deposition rate was about 0.35 nm/s under the high laser fluence condition with lens focusing, while a high deposition rate of 20 nm/s was obtained under the low laser fluence condition without lens focusing. This result suggests that the excess kinetic energy of the deposition precursor in the case of lens-focused deposition causes re-sputtering on the surface of the already deposited film, resulting in a reduction of the effective deposition rate.In the presentation, we will demonstrate and discuss the results of crystallinity and optical absorption properties.[1] T. Miyasaka, A. Kulkarni, G. M. Kim, S. Öz and A. K. Jena, Adv. Energy Mater. 2020, 11902500 (2020).[2] K. Kawashima, Y. Okamoto, O. Annayev, N. Toyokura, R. Takahashi, M. Lippmaa, K. Itaka, Y. Suzuki, N. Matsuki and H. Koinuma, Science and Technology of Advanced Materials 18, 307 (2017).[3] N. Matsuki, Y. Iida, T. Shimada, Yuta Abeand T. Sato, ECS Meeting abst. MA2020-02, 1860 (2020). Figure 1