Uses of Physical Vapor Deposition Processes in Photoelectrochemical Water Splitting Systems

2016 ◽  
Vol 3 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Pedro Migowski ◽  
Adriano F. Feil
Keyword(s):  
Water Splitting ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Low Cost ◽  
High Vacuum ◽  
Thin Layers ◽  
Photoelectrochemical Cells ◽  
Gas Source ◽  
Deposition Processes ◽  
Semiconducting Electrode

AbstractMost of the hydrogen on planet earth is found bound to oxygen atoms in water, making H2O one of the most promising H2 storage molecules. Large availability, non-toxicity and low cost are among the advantages of using H2O as a H2 gas source. However, the decomposition of water into H2 and O2, called water splitting, needs a large amount of energy, increasing the final cost per kg of hydrogen produced. In this context, the energy provided by the sun may be used to power photoelectrochemical cells (PEC) for water splitting to produce cheap and high purity H2. This mini-review will show recent advances on the use of physical vapor deposition (PVD) methods to improve semiconducting electrode performance. PVD enables the preparation of thin layers of expensive materials over photoelectrodes, therefore decreasing PEC systems manufacture costs. Moreover, the interface of between the semiconductor and the evaporated materials can be optimized under high vacuum conditions used in PVD processes and more efficient PEC systems can be obtained.

High Knudsen Number Physical Vapor Deposition: Predicting Deposition Rates and Uniformity

2006 ◽  
Vol 129 (11) ◽  
pp. 1546-1553 ◽  
Author(s):  
Chetan P. Malhotra ◽  
Roop L. Mahajan ◽  
W. S. Sampath
Keyword(s):  
Finite Element ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
High Vacuum ◽  
Thickness Variation ◽  
Molecular Flow ◽  
Vacuum Deposition ◽  
Deposition Rates ◽  
Finite Element Software ◽  
Deposition Processes

The problem of predicting deposition rates and film thickness variation is relevant to many high-vacuum physical vapor deposition (PVD) processes. Analytical methods for modeling the molecular flow fail when the geometry is more complicated than simple tubular or planar sources. Monte Carlo methods, which have traditionally been used for modeling PVD processes in more complicated geometries, being probabilistic in nature, entail long computation times, and thus render geometry optimization for deposition uniformity a difficult task. Free molecular flow is governed by the same line-of-sight considerations as thermal radiation. Though the existence of an analogy between the two was recognized by Knudsen (1909, Ann. Phys., 4(28), pp. 75–130) during his early experiments, it has not been exploited toward mainstream analysis of deposition processes. With the availability of commercial finite element software having advanced geometry modelers and built-in cavity radiation solvers, the analysis of diffuse thermal radiation problems has become considerably simplified. Hence, it is proposed to use the geometry modeling and radiation analysis capabilities of commercial finite element software toward analyzing and optimizing high-vacuum deposition processes by applying the radiation-molecular flow analogy. In this paper, we lay down this analogy and use the commercial finite element software ABAQUS for predicting radiation flux profiles from planar as well as tube sources. These profiles are compared to corresponding deposition profiles presented in thin-film literature. In order to test the ability of the analogy in predicting absolute values of molecular flow rates, ABAQUS was also employed for calculating the radiative flux through a long tube. The predictions are compared to Knudsen’s analytical formula for free molecular flow through long tubes. Finally, in order to see the efficacy of using the analogy in modeling the film thickness variation in a complex source-substrate configuration, an experiment was conducted where chromium films were deposited on an asymmetric arrangement of glass slides in a high-vacuum PVD chamber. The thickness of the deposited films was measured and the source-substrate configuration was simulated in ABAQUS. The variation of radiation fluxes from the simulation was compared to variation of the measured film thicknesses across the slides. The close agreement between the predictions and experimental data establishes the feasibility of using commercial finite element software for analyzing high vacuum deposition processes.

scholarly journals Characterization of Thin Chromium Coatings Produced by PVD Sputtering for Optical Applications

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 215
Author(s):  
Andreia A. Ferreira ◽  
Francisco J. G. Silva ◽  
Arnaldo G. Pinto ◽  
Vitor F. C. Sousa
Keyword(s):  
Automotive Industry ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Early Stage ◽  
Chemical Vapor ◽  
Experimental Tests ◽  
Scratch Test ◽  
Industrial Sectors ◽  
Deposition Processes ◽  
Optical Applications

PVD (physical vapor deposition) and CVD (chemical vapor deposition) have gained greater significance in the last two decades with the mandatory shift from electrodeposition processes to clean deposition processes due to environmental, public safety, and health concerns. Due to the frequent use of coatings in several industrial sectors, the importance of studying the chromium coating processes through PVD–sputtering can be realized, investing in a real alternative to electroplated hexavalent chromium, usually denominated by chromium 6, regularly applied in electrodeposition processes of optical products in the automotive industry. At an early stage, experimental tests were carried out to understand which parameters are most suitable for obtaining chromium coatings with optical properties. To study the coating in a broad way, thickness and roughness analysis of the coatings obtained using SEM and AFM, adhesion analyzes with the scratch-test and transmittance by spectrophotometry were carried out. It was possible to determine that the roughness and transmittance decreased with the increase in the number of layers, the thickness of the coating increased linearly, and the adhesion and resistance to climatic tests remained positive throughout the study. Thus, this study allows for the understanding that thin multilayered Cr coatings can be applied successfully to polymeric substrates regarding optical applications in the automotive industry.

Optical Thin Films of Metal Oxides Produced by the Sol-Gel Method for Photovoltaic Applications

2019 ◽  
Vol 293 ◽  
pp. 83-95
Author(s):  
Marek Szindler
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Light Transmission ◽  
Sol Gel ◽  
Thin Layers ◽  
Gel Method ◽  
Sol Gel Method ◽  
Wide Range

The use of thin films in optoelectronic and photovoltaic devices is aimed at improving the physical properties of the substrate material. The modification of the surface of the silicon substrate is thus one of the greatest challenges in research on photovoltaic materials, in order to achieve even greater efficiency or better adapt their properties depending on the application. The technologies of applying layers vary depending on the effect to be obtained and the material from which the layer is formed. In practice, the most common method is chemical vapor deposition and physical vapor deposition, and the most commonly applied optical materials are SiO2, TiO2 and Si3N4.This paper presents the results of investigations on morphology and optical properties of the prepared aluminium oxide thin films. Thin films were prepared with use of sol-gel spin coating method. Surface morphology studies were carried out using an atomic force microscope. To characterize the surface of the thin films, 3D images and histograms of the frequency of individual inequalities were made. In order to characterize the optical properties of Al2O3 thin films, the reflectance and light transmission tests were performed using a spectrophotometer. Optical constants were determined using a spectroscopic ellipsometer. Results and their analysis show that the sol-gel method allows the deposition of homogenous thin films of Al2O3 with the desired geometric characteristics and good optical properties. Uniform, continuous thin layers with a roughness not exceeding a few nanometres were deposited. Their deposition enabled to reduce the reflection of light from the polished substrate below 15% in a wide range (425-800nm) while maintaining high transparencies (over 90%). The obtained results causes that mentioned thin films are good potential material for optics, optoelectronics and photovoltaics.

scholarly journals A General Concept for Solar Water‐Splitting Monolithic Photoelectrochemical Cells Based on Earth‐Abundant Materials and a Low‐Cost Photovoltaic Panel

2020 ◽  
Vol 4 (2) ◽  
pp. 1900102
Author(s):  
Sitthichok Kasemthaveechok ◽  
Kiseok Oh ◽  
Bruno Fabre ◽  
Jean‐François Bergamini ◽  
Cristelle Mériadec ◽  
...  
Keyword(s):  
Water Splitting ◽  
Low Cost ◽  
General Concept ◽  
Photoelectrochemical Cells ◽  
Photovoltaic Panel ◽  
Solar Water ◽  
Solar Water Splitting ◽  
Earth Abundant

The Application of Wear Resistant Thin Layers for Cold Forming Tools

2014 ◽  
Vol 782 ◽  
pp. 619-622 ◽  
Author(s):  
Pavol Beraxa ◽  
Lucia Domovcová ◽  
Ľudovít Parilák
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Operating Conditions ◽  
Thin Layers ◽  
Treatment Technology ◽  
Cold Forming ◽  
Forming Tools

Along with technologies development rise demands on the technical level of new machinery and equipment and also the reliability and efficiency of tools used in the production processes. One of the options for increasing tool life and wear resistance is the use of tools surface treatment technology called as CVD (chemical vapor deposition) and PVD (Physical Vapor Deposition) process. Chemical vapor deposition is a widely used materials-processing. CVD is an atomistic surface modification process, where a thin solid coating is deposited on an underlying heated substrate via a chemical reaction from the vapor or gas phase, PVD process is atomistic deposition process in which material is vaporized from a solid or liquid source in the form of atoms or molecules, transported in the form of a vapor through a vacuum or low pressure gaseous (or plasma) environment to the substrate where it condenses. The paper introduces the possibilities of application of these processes for cold forming tools used at operating conditions of Železiarne Podbrezová, a.s. Tools (formers and straightening rolls) are evaluated in terms of CVD and PVD coating thickness, microstructure and microhardness of tool material and coating.

scholarly journals A General Concept for Solar Water-Splitting Monolithic Photoelectrochemical Cells Based on Earth-Abundant Materials and a Low-Cost Photovoltaic Panel

2018 ◽  
Vol 2 (11) ◽  
pp. 1800075 ◽  
Author(s):  
Sitthichok Kasemthaveechok ◽  
Kiseok Oh ◽  
Bruno Fabre ◽  
Jean-François Bergamini ◽  
Cristelle Mériadec ◽  
...  
Keyword(s):  
Water Splitting ◽  
Low Cost ◽  
General Concept ◽  
Photoelectrochemical Cells ◽  
Photovoltaic Panel ◽  
Solar Water ◽  
Solar Water Splitting ◽  
Earth Abundant

Progress in Optimization of Physical Vapor Deposition of Thin Films

2021 ◽  
pp. 243-259
Author(s):  
Fredrick M. Mwema ◽  
Esther T. Akinlabi ◽  
Oluseyi Philip Oladijo
Keyword(s):  
Thin Film ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Evaluation Criteria ◽  
Chemical Deposition ◽  
Thin Film Deposition ◽  
Optimization Techniques ◽  
Film Deposition ◽  
Physical Deposition ◽  
Deposition Processes

In this chapter, the current state of the art in optimization of thin film deposition processes is discussed. Based on the reliable and credible published results, the study aims to identify the applications of various optimization techniques in the thin film deposition processes, with emphasis on physical deposition methods. These methods are chosen due to their attractive attributes over chemical deposition techniques for thin film manufacturing. The study identifies the critical parameters and factors, which are significant in designing of the optimization algorithms based on the specific deposition methods. Based on the specific optimization studies, the chapter provides general trends, optimization evaluation criteria, and input-output parameter relationships on thin film deposition. Research gaps and directions for future studies on optimization of physical vapor deposition methods for thin film manufacturing are provided.

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