Topical Collection "Feature Paper Collection in Thin Films"

A topical collection in Coatings (ISSN 2079-6412). This collection belongs to the section "Thin Films".

Editors

Dr. Torsten Brezesinski
E-Mail Website
Collection Editor
Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Bldg. 717, 76344 Eggenstein-Leopoldshafen, Germany
Interests: Li-ion batteries; Li-S batteries; all-solid-state batteries; pseudocapacitors; thin films; materials science; mesoporous materials; self-assembled nanostructures; structure-property relationships
Special Issues, Collections and Topics in MDPI journals
Dr. Ben Breitung
E-Mail Website
Collection Editor
Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Bldg. 640, 76344 Eggenstein-Leopoldshafen, Germany
Interests: high-entropy ceramics; printed electronics; batteries; electrochemistry; semiconductors; thin films; materials science; structure-property relationships

Topical Collection Information

Dear Colleagues,

Oxides and non-oxides in thin-film form are technologically important materials with a variety of applications in energy storage and conversion, sensing, electronics, mechanics, optics and biomedicine, resulting from unique combinations of properties. Inorganic, organic, and hybrid inorganic-organic materials can be produced with a range of structures, compositions, and thicknesses by physical and chemical deposition methods (e.g., atomic layer deposition, pulsed laser deposition, chemical vapor deposition, chemical solution deposition, etc.), with low-cost solution processing routes being usually more flexible in terms of chemistry. Apart from interfacial engineering and compositional design, nanoscale structuring at different length scales—through “top-down” and “bottom-up” approaches—has been shown to be effective in tailoring the properties of thin-film materials. However, the characterization becomes increasingly difficult with decreasing film thickness, and often the lack of structure-property relationship understanding is an impediment to applications. This “Feature Paper Collection” is dedicated to advanced thin film structures and devices, with special emphasis placed on their preparation, characterization, and application in the energy field.

Potential topics include (but are not limited to):

  • Novel oxide and non-oxide materials in thin-film form
  • Preparation by chemical and physical methods
  • Micro- and nanostructuring
  • Surface and interface engineering
  • Advanced characterization techniques
  • Structure–composition–property relationships
  • Application in electrochemical energy storage devices (e.g., as protective surface coating on anode/cathode materials for bulk-type batteries or as active component in thin-film batteries), catalysis, solar cells, sensors, data storage, etc.

Dr. Torsten Brezesinski
Dr. Ben Breitung
Collection Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Coatings is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (6 papers)

2022

Jump to: 2021

Article
Synthesis of High Quality Transparent Nanocrystalline Diamond Films on Glass Substrates Using a Distributed Antenna Array Microwave System
Coatings 2022, 12(10), 1375; https://doi.org/10.3390/coatings12101375 - 20 Sep 2022
Viewed by 241
Abstract
Diamond is a material of choice for the fabrication of optical windows and for protective and anti-reflecting coatings for optical materials. For these kinds of applications, the diamond coating must have a high purity and a low surface roughness to guarantee a high [...] Read more.
Diamond is a material of choice for the fabrication of optical windows and for protective and anti-reflecting coatings for optical materials. For these kinds of applications, the diamond coating must have a high purity and a low surface roughness to guarantee a high transparency. It should also be synthesized at low surface temperature to allow the deposition on low melting-point substrates such as glasses. In this work, the ability of a Distributed Antenna Array (DAA) microwave system operating at low temperature and low pressure in H2/CH4/CO2 gas mixture to synthesize nanocrystalline diamond (NCD) films on borosilicate and soda-lime glass substrates is investigated aiming at optical applications. The influence of the substrate temperature and deposition time on the film microstructure and optical properties is examined. The best film properties are obtained for a substrate temperature below 300 °C. In these conditions, the growth rate is around 50 nm·h−1 and the films are homogeneous and formed of spherical aggregates composed of nanocrystalline diamond grains of 12 nm in size. The resulting surface roughness is then very low, typically below 10 nm, and the diamond fraction is higher than 80%. This leads to a high transmittance of the NCD/glass systems, above 75%, and to a low absorption coefficient of the NCD film below 103 cm−1 in the visible range. The resulting optical band gap is estimated at 3.55 eV. The wettability of the surface evolves from a hydrophilic regime on the bare glass substrates to a more hydrophobic regime after NCD deposition, as assessed by the increase of the measured contact angle from less than 55° to 76° after the deposition of 100 nm thick NCD film. This study emphasizes that such transparent diamond films deposited at low surface temperature on glass substrate using the DAA microwave technology can find applications for optical devices. Full article
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Article
Study on Deuterium Permeation Behavior of Palladium Films Prepared by Magnetron Sputtering Method
Coatings 2022, 12(7), 978; https://doi.org/10.3390/coatings12070978 - 10 Jul 2022
Viewed by 451
Abstract
Pre-depositing a Pd film is crucial for accurately acquiring the hydrogen permeability of metal materials, as it permits the production of ultra-pure hydrogen. However, the microstructure of Pd film and its effect on the hydrogen isotope permeation behavior of substrate materials have been [...] Read more.
Pre-depositing a Pd film is crucial for accurately acquiring the hydrogen permeability of metal materials, as it permits the production of ultra-pure hydrogen. However, the microstructure of Pd film and its effect on the hydrogen isotope permeation behavior of substrate materials have been neglected. In this study, Pd films were deposited on China Low-activation Ferritic (CLF−1) steel by magnetron sputtering. The effect of sputtering pressure on the microstructure and deuterium permeation behavior of Pd films at temperatures of 550−650 °C is presented. SEM results demonstrated that the films had a columnar crystal structure with a thickness of 0.6 ± 0.2 μm. The gas-driven permeation results revealed that the deuterium ion current intensity of the coated CLF−1 sample was at least three times lower than that of uncoated CLF−1 steel, which was influenced by the combined effect of oxygen and surface cracks. Oxygen could not be excluded from the films at a sputtering pressure of 10−3 Pa order of magnitude. It was also found that the films cracked during deuterium permeation experiments, which affected the deuterium permeation behavior. Films with large surface coverage and small grain sizes exhibited better cracking resistance. Our study provides promising insights into the hydrogen permeability of Pd films. Full article
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Article
Diffusion Barrier Characteristics of WSiN Films
Coatings 2022, 12(6), 811; https://doi.org/10.3390/coatings12060811 - 10 Jun 2022
Viewed by 408
Abstract
WSiN films were produced through hybrid pulse direct current/radio frequency magnetron co-sputtering and evaluated as diffusion barriers for Cu metallization. The Cu/WSiN/Si assemblies were annealed for 1 h in a vacuum at 500–900 °C. The structural stability and diffusion barrier performance of the [...] Read more.
WSiN films were produced through hybrid pulse direct current/radio frequency magnetron co-sputtering and evaluated as diffusion barriers for Cu metallization. The Cu/WSiN/Si assemblies were annealed for 1 h in a vacuum at 500–900 °C. The structural stability and diffusion barrier performance of the WSiN films were explored through X-ray diffraction, Auger electron spectroscopy, and sheet resistance measurement. The results indicated that the Si content of WSiN films increased from 0 to 9 at.% as the power applied to the Si target was increased from 0 to 150 W. The as-deposited W76N24, W68Si0N32, and W63Si4N33 films formed a face-centered cubic W2N phase, whereas the as-deposited W59Si9N32 film was near-amorphous. The lattice constants of crystalline WSiN films decreased after annealing. The sheet resistance of crystalline WSiN films exhibited a sharp increase as they were annealed at 800 °C, accompanied by the formation of a Cu3Si compound. The failure of the near-amorphous W59Si9N32 barrier against Cu diffusion was observed when annealed at 900 °C. Full article
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Article
Preparation of Very Thin Zinc Oxide Films by Liquid Deposition Process: Review of Key Processing Parameters
Coatings 2022, 12(1), 65; https://doi.org/10.3390/coatings12010065 - 06 Jan 2022
Cited by 3 | Viewed by 561
Abstract
We used sol-gel and spin-coating in the original configuration of a liquid deposition process to synthesize particularly thin ZnO films (<100 nm) with nano-granular morphology, high grain orientation and variable optical properties. The concentration of the zinc salt, the concentration of the chelating [...] Read more.
We used sol-gel and spin-coating in the original configuration of a liquid deposition process to synthesize particularly thin ZnO films (<100 nm) with nano-granular morphology, high grain orientation and variable optical properties. The concentration of the zinc salt, the concentration of the chelating agent, the nature of the solvent and the substrate material have been identified as key parameters that determine the microstructure of the deposited layer and thus its final properties. The thorough and practical examination of the effects of the synthesis parameters evidenced a three-step growth mechanism for these ZnO thin films: (i) a reaction of precursors, (ii) a formation of nuclei, and (iii) a coalescence of nanoparticles under thermal annealing. The growth of these very thin films is thus conditioned by the interaction between the liquid phase and the substrate especially during the initial steps of the spin coating process. Such thin ZnO films with such nano-granular morphology may be of great interest in various applications, especially those requiring a large active surface area. Full article
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2021

Jump to: 2022

Article
Tuning the Electrical Properties of NiO Thin Films by Stoichiometry and Microstructure
Coatings 2021, 11(6), 697; https://doi.org/10.3390/coatings11060697 - 10 Jun 2021
Cited by 1 | Viewed by 907
Abstract
Here, the electrical properties of NiO thin films grown on glass and Al2O3 (0001) substrates have been investigated. It was found that the resistivity of NiO thin films strongly depends on oxygen stoichiometry. Nearly perfect stoichiometry yields extremely high resistivity. [...] Read more.
Here, the electrical properties of NiO thin films grown on glass and Al2O3 (0001) substrates have been investigated. It was found that the resistivity of NiO thin films strongly depends on oxygen stoichiometry. Nearly perfect stoichiometry yields extremely high resistivity. In contrast, off-stoichiometric thin films possess much lower resistivity, especially for oxygen-rich composition. A side-by-side comparison of energy loss near the edge structure spectra of Ni L3 edges between our NiO thin films and other theoretical spectra rules out the existence of Ni3+ in NiO thin films, which contradicts the traditional hypothesis. In addition, epitaxial NiO thin films grown on Al2O3 (0001) single crystal substrates exhibit much higher resistivity than those on glass substrates, even if they are deposited simultaneously. This feature indicates the microstructure dependence of electrical properties. Full article
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Article
Influence of the Physical Properties on the Antibacterial and Photocatalytic Behavior of Ag-Doped Indium Sulfide Film Deposited by Spray Pyrolysis
Coatings 2021, 11(4), 370; https://doi.org/10.3390/coatings11040370 - 24 Mar 2021
Cited by 2 | Viewed by 1214
Abstract
Spray pyrolysis was used to deposit indium sulfide (In2S3) films, with or without silver doping. The films are polycrystalline, and the inclusion of Ag in the In2S3 structure leads to the formation of a solid solution, [...] Read more.
Spray pyrolysis was used to deposit indium sulfide (In2S3) films, with or without silver doping. The films are polycrystalline, and the inclusion of Ag in the In2S3 structure leads to the formation of a solid solution, with the crystallite size of the order of tens of nanometers. In2S3 films exhibit a semiconductive behavior, and the incorporation of Ag leads to an increase of the charge carrier concentration, enhancing the electrical conductivity of the films. The small polaron hopping mechanism, deduced by the fittings according to the double Jonscher variation, explains the evolution of the direct current (dc) conductivity at high temperature of the Ag-doped indium sulfide. From impedance spectroscopy, it was found that the doped film presents dielectric relaxation, and Nyquist diagrams indicate the importance of the grain and the grain boundaries’ contributions to the transport phenomena. The physical characteristics of the films have an influence on the photocatalytic performance, achieving photodegradation efficiency above 80% (85.5% in the case of Ag doping), and on the antibacterial activity. The obtained results indicate that indium sulfide films are good candidates for environmental and biological applications, confirming a multifunctional nature. Full article
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