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13 pages, 9405 KiB

Open AccessArticle

Synthesis of ZnO/Bi₂S₃ Core/Shell Nanowire Array Photoanodes for Photocathodic Protection of Stainless Steel

by Yichang Lin and Sheng Liu

Coatings 2022, 12(2), 244; https://doi.org/10.3390/coatings12020244 - 13 Feb 2022

Cited by 3 | Viewed by 1899

Nanocrystalline Bi₂S₃ shells were conformally deposited on ZnO nanowire arrays via a successive ionic layer adsorption and reaction approach. Microstructure, optical, and electric properties of the as-prepared ZnO/Bi₂S₃ core/shell nanowire heterostructures were thoroughly investigated using various characterization [...] Read more.

Nanocrystalline Bi₂S₃ shells were conformally deposited on ZnO nanowire arrays via a successive ionic layer adsorption and reaction approach. Microstructure, optical, and electric properties of the as-prepared ZnO/Bi₂S₃ core/shell nanowire heterostructures were thoroughly investigated using various characterization and electrochemical methods. Compared with the pristine ZnO photoanode (−734 mV and 0.57 mA·cm⁻²), the ZnO/Bi₂S₃ photoanode with a type-II heterojunction exhibited a more negative shift in the coupled open circuit potential (−862 mV) and a higher photocurrent density (2.92 mA·cm⁻²), achieving more effective photocathodic protections for the coupled 304 stainless steel under solar illumination. Full article

(This article belongs to the Special Issue Thin Films and Coatings for Energy Application)

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13 pages, 5617 KiB

Open AccessArticle

Mo Contact via High-Power Impulse Magnetron Sputtering on Polyimide Substrate

by Yung-Lin Chen, Yi-Cheng Lin and Wan-Yu Wu

Coatings 2022, 12(1), 96; https://doi.org/10.3390/coatings12010096 - 14 Jan 2022

Cited by 2 | Viewed by 2395

Abstract

It has always been a huge challenge to prepare the Mo back contact of inorganic compound thin film solar cells (e.g., CIGS, CZTS, Sb₂Se₃) with good conductivity and adhesion at the same time. High-power impulse magnetron sputtering (HiPIMS) has [...] Read more.

It has always been a huge challenge to prepare the Mo back contact of inorganic compound thin film solar cells (e.g., CIGS, CZTS, Sb₂Se₃) with good conductivity and adhesion at the same time. High-power impulse magnetron sputtering (HiPIMS) has been proposed as one solution to improve the properties of the thin film. In this study, the HiPIMS technology replaced the traditional DC power sputtering technology to deposit Mo back contact on polyimide (PI) substrates by adjusting the experimental parameters of HiPIMS, including working pressure and pulse DC bias. When the Mo back contact is prepared under a working pressure of 5 mTorr and bias voltage of −20 V, the conductivity of the Mo back contact is 9.9 × 10⁻⁶ Ω·cm, the residual stress of 720 MPa, and the film still has good adhesion. Under the minimum radius of curvature of 10 mm, the resistivity change rate of Mo back contact does not increase by more than 15% regardless of the 1680 h or 1500 bending cycle tests, and the Mo film still has good adhesion in appearance. Experimental results show that, compared with traditional DC sputtering, HiPIMS coating technology has better conductivity and adhesion at the same time, and is especially suitable for PI substrates. Full article

(This article belongs to the Special Issue Thin Films and Coatings for Energy Application)

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16 pages, 2969 KiB

Open AccessArticle

Evaluation of SnS:Cu Thin Film Properties Obtained by USP Technique to Implement It as an Absorbent Layer in Solar Cells Using SCAPS

by Sergio Rodríguez-Castro, Carlos Álvarez-Macías, Michel Rivero, Lizbeth Salgado-Conrado, Rodrigo Loera-Palomo, Bernardo Reyes-Durán and Jorge Narro-Ríos

Coatings 2021, 11(7), 754; https://doi.org/10.3390/coatings11070754 - 23 Jun 2021

Cited by 7 | Viewed by 2444

Abstract

Tin sulfide doped with copper (SnS:Cu) thin films were deposited on glass substrates by the ultrasonic spray pyrolysis (USP) technique at different concentration ratios (y = [Cu]/[Sn] = 0% (undoped), 2%, 5% and 10%). The aim of this work is to analyze [...] Read more.

Tin sulfide doped with copper (SnS:Cu) thin films were deposited on glass substrates by the ultrasonic spray pyrolysis (USP) technique at different concentration ratios (y = [Cu]/[Sn] = 0% (undoped), 2%, 5% and 10%). The aim of this work is to analyze the effect of copper on structural, morphological, and optoelectronic properties of SnS:Cu and discuss their possible application as an absorber layer in a solar cell structure proposed which is simulated using SCAPS software. X-ray diffraction (XRD) reveals an orthorhombic structure in the undoped sample and a cubic structure in doped ones. Raman spectroscopy suggests a possible unit cell size change due to the addition of Cu. Scanning electron microscopy (SEM) shows growth in grain density with an increasing y. Image analysis based on second-order features was used to discuss grain distribution. UV-VIS spectroscopy helps to find an increase of bandgap for the doped samples when copper concentration increases, going from 1.82 eV in the doped film y = 2% to 2.2 eV in the 10% doped samples. A value of 3.51 eV was found for the undoped sample y = 0%. A rise in both carrier concentration and mobility but a decrease in resistivity when y is increased was observed through the Hall–Van der Pauw technique. Simulations by SCAPS helped conclude that considering the material thickness, the SnS:Cu compound can be an alternative for implementation in the manufacturing of solar cells as an absorber layer since it is possible to obtain the optoelectronic properties necessary using the UPS economical technique. Full article

(This article belongs to the Special Issue Thin Films and Coatings for Energy Application)

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13 pages, 2857 KiB

Open AccessArticle

Design and Optimization of the Antireflective Coating Properties of Silicon Solar Cells by Using Response Surface Methodology

by Yahia F. Makableh, Hani Alzubi and Ghassan Tashtoush

Coatings 2021, 11(6), 721; https://doi.org/10.3390/coatings11060721 - 16 Jun 2021

Cited by 9 | Viewed by 3795

Abstract

The design and optimization of a nanostructured antireflective coatings for Si solar cells were performed by using response surface methodology (RSM). RSM was employed to investigate the effect on the overall optical performance of silicon solar cells coated with three different nanoparticle materials [...] Read more.

The design and optimization of a nanostructured antireflective coatings for Si solar cells were performed by using response surface methodology (RSM). RSM was employed to investigate the effect on the overall optical performance of silicon solar cells coated with three different nanoparticle materials of titanium dioxide, aluminum oxide, and zinc oxide nanostructures. Central composite design was used for the optimization of the reflectance process and to study the main effects and interactions between the three process variables: nanomaterial type, the radius of nanoparticles, and wavelength of visible light. In this theoretical study, COMSOL Multiphysics was utilized to design the structures by using the wave optics module. The optical properties of the solar cell’s substrate and the three different nanomaterial types were studied. The results indicated that ZnO nanoparticles were the best antireflective coating candidate for Si, as the ZnO nanoparticles produced the lowest reflection values among the three nanomaterial types. The study reveals that the optimum conditions to reach minimum surface reflections for silicon solar cell were established by using ZnO nanoparticles with a radius of ~38 nm. On average, the reflectance reached ~5.5% along the visible spectral range, and approximately zero reflectance in the 550–600 nm range. Full article

(This article belongs to the Special Issue Thin Films and Coatings for Energy Application)

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15 pages, 4374 KiB

Open AccessArticle

Investigation of Catalyst Development from Mg₂NiH₄ Hydride and Its Application for the CO₂ Methanation Reaction

by Martynas Lelis, Sarunas Varnagiris, Marius Urbonavicius and Kestutis Zakarauskas

Coatings 2020, 10(12), 1178; https://doi.org/10.3390/coatings10121178 - 1 Dec 2020

Cited by 6 | Viewed by 2181

Abstract

In current study various aspects of catalyst development for the Sabatier type methanation reaction were investigated. It was demonstrated that starting from 330–380 °C Mg₂NiH₄ hydride heating under CO₂ and H₂ gas flow initiates hydride decomposition, disproportionation and [...] Read more.

In current study various aspects of catalyst development for the Sabatier type methanation reaction were investigated. It was demonstrated that starting from 330–380 °C Mg₂NiH₄ hydride heating under CO₂ and H₂ gas flow initiates hydride decomposition, disproportionation and oxidation. These reactions empower catalytic properties of the material and promotes CO₂ methanation reaction. Detailed structural, colorimetric and thermogravimetric analysis revealed that in order to have fast and full-scale development of the catalyst (formation of MgO decorated by nanocrystalline Ni) initial hydride has to be heated above 500 °C. Another considerable finding of the study was confirmation that potentially both high grade and low grade starting Mg₂Ni alloy can be equally suitable for the hydride synthesis and its usage for the promotion of methanation reactions. Full article

(This article belongs to the Special Issue Thin Films and Coatings for Energy Application)

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10 pages, 3357 KiB

Open AccessArticle

Novel Tunable Green-Red Luminescence in Mn²⁺ Doped Ca₉Tb(PO₄)₇ Phosphors Based on the Mn²⁺ Regulation and Energy Transfer

by Bingwen Yang, Yefeng Feng, Qinghu Zhao, Miao He and Yang Lv

Coatings 2020, 10(10), 952; https://doi.org/10.3390/coatings10100952 - 1 Oct 2020

Cited by 5 | Viewed by 1979

Abstract

β-Ca₃(PO₄)₂ type phosphors Ca₉Tb(PO₄)₇:Mn²⁺ were fabricated by high temperature solid state reaction. Under 377 nm light excitation, the Ca₉Tb(PO₄)₇ host displays the green emission attributable to [...] Read more.

β-Ca₃(PO₄)₂ type phosphors Ca₉Tb(PO₄)₇:Mn²⁺ were fabricated by high temperature solid state reaction. Under 377 nm light excitation, the Ca₉Tb(PO₄)₇ host displays the green emission attributable to the characteristic emission of Tb³⁺ ions peaking at 488, 542, 586, and 620 nm, respectively. The red broadband emission is observed when Ca₉Tb(PO₄)₇ is doped with Mn²⁺ ions. The emission is attributed to the energy transfer from Tb³⁺ to Mn²⁺ ions; this facilitates the realization of the tunable green–red emission. The energy transfer mechanism from Tb³⁺ to Mn²⁺ is defined as quadrupole–quadrupole interaction. Furthermore, the thermal stability of Ca₉Tb(PO₄)₇:Mn²⁺ samples has been studied, and it can maintain half the emission intensity exceeding 424 K. This demonstrates their potential applications in white light LEDs (w-LEDs). Full article

(This article belongs to the Special Issue Thin Films and Coatings for Energy Application)

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16 pages, 11475 KiB

Open AccessArticle

Performance Optimization of Original Aluminum Ash Coating

by Hongjun Ni, Jiaqiao Zhang, Shuaishuai Lv, Tao Gu and Xingxing Wang

Coatings 2020, 10(9), 831; https://doi.org/10.3390/coatings10090831 - 27 Aug 2020

Cited by 6 | Viewed by 2047

Abstract

Aluminum ash is a kind of industrial solid waste. Original aluminum ash (OAA) can be prepared into original aluminum ash spray powder (OAASP) through hydrolysis treatment, and the original aluminum ash coating (OAAC) can be prepared on the surface of the substrate by [...] Read more.

Aluminum ash is a kind of industrial solid waste. Original aluminum ash (OAA) can be prepared into original aluminum ash spray powder (OAASP) through hydrolysis treatment, and the original aluminum ash coating (OAAC) can be prepared on the surface of the substrate by plasma spraying. In order to optimize the performance of the OAAC, the OAASP was screened to select the appropriate particle size to improve the flowability of the powder. Then, the influence of the alumina content on coating performance was studied through comparative experiments. The micro morphology of the coating was analyzed, and the performance parameters of the coating were tested. The results show that the spray powder with a particle size of 120–150 mesh accounts for the largest proportion of OAASP, and its flowability is better than that of unsieved OAASP, which is suitable for coating preparation. The performance of the coating can be improved by adding high-purity alumina. When the Al₂O₃ addition is 50%, the porosity of the coating is 0.131%, the adhesive strength is 17.12 MPa, the microhardness is 713.36 HV, and the abrasion rate 10.31 mg/min. Compared with the coating without Al₂O₃, the porosity is decreased by 19.63%, the adhesive strength is increased by 5.35%, the microhardness is increased by 17.61%, and the abrasion rate is decreased by 19.83%. There are regions with different brightness on the surface of the coating with Al₂O₃. After semiquantitative analysis, the main phase in the bright region is Al₂O₃, and the main phases in the dark and gray regions are Al₂O₃, SiO₂, and Fe₃O₄. The performance of the OAAC can be optimized by improving the flowability of the sprayed powder and increasing the alumina content. Full article

(This article belongs to the Special Issue Thin Films and Coatings for Energy Application)

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17 pages, 5192 KiB

Open AccessArticle

Coating Process Parameters and Structural Properties of the Tubular Electrodes of Fuel Cells Based on a Self-Made Coating Device

by Hongjun Ni, Jiaqiao Zhang, Shuaishuai Lv, Xingxing Wang, Yi Pei and Fei Li

Coatings 2020, 10(9), 830; https://doi.org/10.3390/coatings10090830 - 27 Aug 2020

Cited by 3 | Viewed by 2881

Abstract

The electrode is one of the most important components of tubular direct methanol fuel cells (DMFC), and the coating process directly determines its performance. In the present research, a tubular electrode coating device was designed based on planetary gear structures, and the influence [...] Read more.

The electrode is one of the most important components of tubular direct methanol fuel cells (DMFC), and the coating process directly determines its performance. In the present research, a tubular electrode coating device was designed based on planetary gear structures, and the influence of the coating process parameters on the electrode structure’s performance was studied. The experimental results show that: the coating layer on the electrode surface prepared by the self-made device is uniform and dense, and the coating surface quality is better than a manual coating. The best coating environment temperature is 30–40 °C, and the coating spindle speed is 6.67 r/min. Under the condition in which Nafion 117 is used as the proton exchange membrane, the fuel cell is placed in 1 mol/L H₂SO₄ + 0.5 mol/L CH₃OH electrolyte, and high-purity oxygen is fed at a rate of 100 mL/min, the power density of the electrode coated by the self-made device can reach 20.50 mW/cm², which is about 2.4 times that of the electrode coated manually. Full article

(This article belongs to the Special Issue Thin Films and Coatings for Energy Application)

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