Fabrication Of Films Research Articles

Low-Temperature Fabrication of Stable Black-Phase CsPbI3 Perovskite Flexible Photodetectors Toward Wearable Health Monitoring.

Flexible wearable optoelectronic devices fabricated from organic-inorganic hybrid perovskites significantly accelerate the development of portable energy, biomedicine, and sensing fields, but their poor thermal stability hinders further applications. Conversely, all-inorganic perovskites possess excellent thermal stability, but black-phase all-inorganic perovskite film usually requires high-temperature annealing steps, which increases energy consumption and is not conducive to the fabrication of flexible wearable devices. In this work, an unprecedented low-temperature fabrication of stable black-phase CsPbI3 perovskite films is demonstrated by the in situ hydrolysis reaction of diphenylphosphinic chloride additive. The released diphenyl phosphate and chloride ions during the hydrolysis reaction significantly lower the phase transition temperature and effectively passivate the defects in the perovskite films, yielding high-performance photodetectors with a responsivity of 42.1A W-1 and a detectivity of 1.3 × 1014Jones. Furthermore, high-fidelity image and photoplethysmography sensors are demonstrated based on the fabricated flexible wearable photodetectors. This work provides a new perspective for the low-temperature fabrication of large-area all-inorganic perovskite flexible optoelectronic devices.

A universal reverse‐cool annealing strategy makes two‐dimensional Ruddlesden‐popper perovskite solar cells stable and highly efficient with Voc exceeding 1.2 V

AbstractTwo‐dimensional Ruddlesden‐Popper (2D RP) layered metal‐halide perovskites have garnered increasing attention due to their favorable optoelectronic properties and enhanced stability in comparison to their three‐dimensional counterparts. Nevertheless, precise control over the crystal orientation of 2D RP perovskite films remains challenging, primarily due to the intricacies associated with the solvent evaporation process. In this study, we introduce a novel approach known as reverse‐cool annealing (RCA) for the fabrication of 2D RP perovskite films. This method involves a sequential annealing process at high and low temperatures for wet perovskite films. The resulting RCA‐based perovskite films show the smallest root‐mean‐square value of 23.1 nm, indicating a minimal surface roughness and a notably compact and smooth surface morphology. The low defect density in these 2D RP perovskite films with exceptional crystallinity suppresses non‐radiative recombination, leading to a minimal non‐radiative open‐circuit voltage loss of 149 mV. Moreover, the average charge lifetime in these films is extended to 56.3 ns, thanks to their preferential growth along the out‐of‐plane direction. Consequently, the leading 2D RP perovskite solar cell achieves an impressive power conversion efficiency of 17.8% and an open‐circuit voltage of 1.21 V. Additionally, the stability of the 2D RP perovskite solar cell, even without encapsulation, exhibits substantial improvement, retaining 97.4% of its initial efficiency after 1000 hours under a nitrogen environment. The RCA strategy presents a promising avenue for advancing the commercial prospects of 2D RP perovskite solar cells.image

Study on the fabrication of high-quality hafnium oxide thin films using spatial rotated atomic layer deposition and supercritical fluids treatment

This study explores the experimental outcomes and discussions surrounding the deposition of high-quality hafnium oxide (HfO2) thin films using spatial rotated atomic layer deposition (SRALD). The primary objective was to enhance the efficiency of ALD processes while maintaining film quality comparable to conventional methods. The SRALD system, developed by Kudos Nano Technology, was employed to deposit HfO2 films over a four-step process. Following deposition, the films underwent high-pressure annealing and supercritical fluids treatment, which are known for reducing thermal budgets. The key findings revealed that high-pressure annealing resulted in a significant reduction in the leakage current by up to 50%, while supercritical fluids treatment improved the dielectric constant of the films, reaching values as high as 23. These treatments also contributed to enhancing the uniformity and density of the films, as confirmed by cross-sectional transmission electron microscopy and x-ray reflectometry analyses. The electrical properties of the resulting metal–insulator–semiconductor capacitors were thoroughly investigated, demonstrating a marked improvement in capacitance-voltage characteristics with minimal hysteresis.

Large-Scale Fabrication of High β-Phase PVDF Films with Enhanced Piezoelectric and Electrode Formation Properties

Large-Scale Fabrication of High β-Phase PVDF Films with Enhanced Piezoelectric and Electrode Formation Properties

Fabrication and characterizations of biodegradable films based on polysaccharide from Pyropia yezoensis waste with antioxidant and antibacterial activities

Fabrication and characterizations of biodegradable films based on polysaccharide from Pyropia yezoensis waste with antioxidant and antibacterial activities

Phase-selective fabrication of Cu-based films by magnetic field-assisted sparking process for improved photocatalytic dye degradation and CO2 reduction

Copper-based films (Cu2(OH)3NO3, Cu2O, and CuO) were successfully synthesized using a sparking process under an external magnetic field, without requiring an annealing process. We thoroughly investigate the impact of magnetic field orientation on the structural, morphological, and optical properties of the films, along with their performance in photocatalytic degradation of methylene blue (MB) and carbon dioxide (CO2) reduction. Field-emission scanning electron microscopy (FE-SEM) images reveal that the CuEB(S) sample displays secondary particles forming spherical, dense clusters, whereas the CuEB(N) sample exhibits larger, loosely packed clusters. In contrast, the cluster-like structures disperse in the CuEB(P) sample, resulting in a smoother film surface aligned with the parallel magnetic flux direction. Upon close observation, rice-shaped particles of varying sizes (26.3–60.3 nm) were found stacked together. This study presents a facile method to selectively fabricate films comprising single-phase Cu2(OH)3NO3, a CuO/Cu2O composite, or a combination of all phases by manipulating the external magnetic field orientation during the sparking process. All synthesized materials exhibit photocatalytic activity, with the heterojunction composed of CuO, Cu2O, and Cu2(OH)3NO3 demonstrating superior performance. This heterostructure achieved up to a 180 % enhancement in MB degradation and approximately doubled the CO2-to-CO conversion rate to 16.09 μmol g–¹ h–¹ compared to the sample prepared without a magnetic field.

A First-principles Investigation of the Structural, Optoelectronic, Elastic and Thermal properties ofthe p-type Half-metallic Ferromagnetic Perovskites BaFeX3(X = Cl, Br, I)

Abstract The half-metallic nature of the metal halide perovskites BaFeX3 (X=Cl, Br,I) and their physical properties were studied using Spin-polarised Density Functional Theory calculations. For each structure, ferromagnetic, antiferromagnetic and non-magnetic calculation were
performed and the ferromagnetic phase was found to have the lowest energy. The calculated band structures in addition to the electronic density of states confirmed half-metallicity, where the perovskites showed semiconducting nature in the spin up
channel and metallic in spin-down channel. The optical properties are calculated and strong absorption in the UV range was seen and the mechanical properties demonstrated mechanical stability with ductile behaviour for all perovskites. The specific heats (at
constant volume) of all of the studied perovskites levelled off to about 245 JK−1mol−1 at high temperatures. The Seebeck coefficient was also calculated as a function of temperature and found to be positive for all the structures which confirm them to be
p-type materials. These perovskites are therefore suited for thin film fabrication and bulk single crystals for applications such as UV photodetectors and energy harvesting, in addition to spintronics applications.

Fabrication and Characterization of Micro-Arc Oxidation Films on β-Titanium Alloy in Silicate and Silicate/Glycerin Electrolyte

Micro-arc oxidation (MAO) films were fabricated on the Ti-39Nb-6Zr alloy at different voltages in the silicate and silicate/glycerin electrolyte. Their morphology, phase structure and composition were characterized by scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was found that the glycerin additive in the silicate electrolyte improved the compactness of the MAO film. The corrosion resistance was evaluated, and the influence of glycerin additive in electrolyte on the growth of micro-arc oxidized film was revealed by optical emission spectra.

Investigation of optoelectronic, mechanical and thermodynamic properties of cubic perovskite FrBCl3 (B = Zn, Cd) in approach of density functional theory

Lead-free cubic metallic halide perovskite (MHP) compounds, FrBCl3 (where B = Zn, Cd), have been evaluated using first-principles density-functional theory (DFT). Both FrZnCl3 and FrCdCl3 satisfy the stability conditions determined by their tolerance and octahedral factors. These materials demonstrate the characteristics of indirect band gap semiconductors, and their high optical absorption coefficients create promising opportunities for the advancement of optoelectronic devices. The elastic properties of both perovskites indicate robust mechanical stability, while their ductility, flexibility, and stiffness suggest potential for thin film fabrication. Furthermore, the Debye temperature profile underscores the thermal stability of these compounds. This computational study reveals coherent relationships among their structural, electronic, optical, mechanical, and thermodynamic properties. Consequently, these materials may offer exciting applications in nuclear medicine, X-ray imaging, and a variety of optoelectronic devices.

Correction: Fabrication and Characterization of Boron-Implanted Silicon Superconducting Thin Films on SOI Substrates for Low-Temperature Detectors

Correction: Fabrication and Characterization of Boron-Implanted Silicon Superconducting Thin Films on SOI Substrates for Low-Temperature Detectors

Electrochemical study of an enhanced platform by electrochemical synthesis of three-dimensional polyaniline nanofibers/reduced graphene oxide thin films for diverse applications

This work reports the electrochemical fabrication of thin films comprising polyaniline nanofibers (PANI) in conjunction with graphene oxide (GO) and reduced graphene oxide (rGO) on ITO substrate, along with examining the electrochemical properties, with a focus on the influence of the substrate and electrolyte in the electrodeposition methods. The study explores the electrochemical characteristics of these thin films and establishes a flexible framework for their application in diverse sectors such as sensors, supercapacitors, and electronic devices. It analyzes the impact of the substrate and electrolyte in electrodeposition techniques. The effects were studied using techniques such as cyclic voltammetry and chronoamperometry. The fabrication process of PANI/GO and PANI/rGO thin films involved the integration of rGO within PANI via electropolymerization, conducted under sulfuric acid. GO was synthesized by modifying the well-known Hummers’ method and characterized by X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). SEM showed the diameters of the formed PANI were between 40 and 150 nm, which helped to intertwine the rGO nanosheets with PANI nanofibers to form thin films. The electrochemical behavior of the PANI/rGO thin films was examined using cyclic voltammetry (CV) and chronoamperometry in different electrolytes, including sulfuric acid (H₂SO₄) and potassium nitrate (KNO₃). The CV profiles exhibited distinct oxidation and reduction peaks, with variations in the voltammogram morphology attributed to the nature of the electrolyte and the substrate employed during the electrodeposition process. These results highlight the critical role of both the substrate and electrolyte in governing the electrochemical performance of PANI/rGO thin films. The findings from this study demonstrate a versatile approach for the fabrication of PANI/graphene-based thin films with tunable electrochemical properties, and such a strategy has great application to fabricating other thin film composites for supercapacitors or other control source frameworks requiring enhanced charge storage and electrochemical responsiveness.

Fabrication and characterization of double-layer active intelligent film based on chitosan, polyvinyl alcohol, grape skin anthocyanin and selenium nanoparticle

This study involved the fabrication of double-layer intelligent films using chitosan (CS), polyvinyl alcohol (PVA), grape skin anthocyanin (GSA), gellan gum (GG) and selenium nanoparticles (SeNPs). The CS/PVA/GSA layer functioned as the internal indicator layer, and the GG/SeNPs layer acted as the external layer for antioxidant and antimicrobial purposes. SEM, FTIR, XRD, and TGA results confirmed the successful fabrication of double-layer films as well as the presence of hydrogen bonding interaction between the two layers. The tensile strength of double-layer films (8.06 MPa–9.61 MPa) fallen between that of single-layer CS/PVA/GSA film (12.51 MPa) and GG/SeNPs film (1.50 MPa–7.67 MPa). The double-layer films demonstrated good UV-blocking abilities, as well as outstanding antioxidant (ABTS scavenging rate can be up to ~80 %) and antimicrobial properties. Compared with single-layer CS/PVA/GSA film, the double-layer film incorporated with 6.6 wt% SeNPs (CPG/GS2 film) possessed a more rapid and stronger response towards NH3/acetic acid as well as enhanced storage stability. Furthermore, the CPG/GS2 film can increase the shelf life of strawberries at 25 °C by 4 days, and its visible color change showed strong correlation with the weight loss rate (R2 = 0.99) and hardness (R2 = 0.98) of strawberries.

Fabrication of thin film for triple-cation perovskite via hot-bar-coating method without post-annealing process

The triple-cation perovskite Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3 was deposited using the hot-bar-coating method. The effects of the substrate temperature and coating bar sweep speed on the film quality were investigated. Coating the precursor solution at a substrate temperature of 150 °C, reduced fabrication time by eliminating the post-annealing process, which is essential to conventional film fabrication methods, i.e., the antisolvent method. We further investigated the dependence of thin film thickness and quality on the coating bar sweep speed, finding that the optimal film quality was achieved at a speed of 4 mm/s. Importantly, decomposition into PbI2 was not observed during film fabrication for the triple-cation perovskite. The results of solar cell property measurements, indicating that the fabricated devices maintained high performance for 500 h in ambient air, suggest that the hot-bar-coating method is a promising approach for producing perovskite solar cells with high atmospheric stability and potentially low cost.

Design and fabrication of multiphase TiVCrZrW films with superior wear resistance and corrosion resistance

High entropy alloys (HEAs) have the potential to overcome the conflict between hardness and toughness by incorporating dual-phase or multiphase structures. Under unbalanced magnetron sputtering, HEA films with large atomic size differences tend to form non-monophasic structures. In this study, based on a phase diagram calculation simulation, a multiphase TiVCrZrW film with deposition temperature-induced phase separation was successfully designed. Interestingly, the TiVCrZrW film deposited at 600 °C exhibited a multiphase structure including a double body-centered cubic (BCC) phase and Laves phase by spinodal decomposition, realizing a balance between hardness and toughness. The tribological experiments showed that the multiphase TiVCrZrW film provided superior wear resistance, with a minimum wear rate of 2.63 × 10−6 mm3/(N·m). The electrochemical experiment demonstrated the outstanding corrosion resistance of the multiphase TiVCrZrW film, and the corrosive solution was effectively inhibited by the ZrO2 and Cr2O3 oxides passive film formed on the surface. According to the results of this study, TiVCrZrW protective films have a wide range of potential applications in various fields of marine engineering.

Solution-processed planarly oriented thin films of cholesteric liquid-crystalline semiconductors

We have successfully fabricated cholesteric liquid-crystalline (CLC) semiconductor thin films from the mixture of dimeric and monomeric compounds based on oligo(p-phenylenevinylene) units by spin-coating method. This is the first example of solution-processed planarly orientated thin film in CLC semiconductors. The mixture exhibited a CLC phase at lower temperatures than the compound alone, allowing the fabrication of spin-coated CLC thin films at room temperature. Furthermore, the dimeric compound has trifluoromethyl groups that exhibited high solubility in organic solvents such as chloroform due to its improved hydrophobicity. In addition, the high hydrophobicity of the trifluoromethyl groups lowers the surface tension of the liquid–crystal material, resulting in planar orientation.

Optoelectronic effect of Al-based buffer layers on Al-doped ZnO thin transparent conductive films on flexible substrates

AZO (Al-doped ZnO) film is a transparent conductive film that offers a simple preparation process, low cost, non-toxicity, and excellent stability. It serves as a high-quality material extensively used in liquid crystal displays, solar cells, and other fields. In this study, AZO thin films were prepared on a PET substrate with an Al2O3 buffer layer using the magnetron sputtering method. The deposition parameters were optimized through the Taguchi method and Grey Correlation Analysis. The results demonstrate that the optimal deposition parameters for achieving superior photoelectric properties during the fabrication of AZO films are 100 W (radio frequency power), 1.0 Pa (sputtering pressure), 20 min (coating time), and 20°C (substrate temperature). Furthermore, the incorporation of an Al2O3 buffer layer enhances the quality of AZO film on PET substrate. This investigation successfully deposited uniform and highly efficient AZO thin films onto flexible PET substrates at low temperatures, thereby expanding their potential applications in flexible electronics.

Self‑supporting magnetic nanoporous silver-nickel films with broadband light absorption for efficient interfacial solar steam generation

Interfacial solar steam generation (SSG) is a promising eco-friendly strategy for freshwater production to address the global water crisis, which depends upon high-efficiency and low-cost photothermal materials. Herein, a series of self-supporting magnetic nanoporous silver-nickel (NP-AgNi) films were fabricated by one-step dealloying of specially designed Al99AgxNi1-x (x = 0.3, 0.5, 0.7) precursors. Both in-situ and ex-situ characterizations were performed to unveil the phase/structure evolution during dealloying of AlAgNi. Specially, the obtained NP-AgNi films with high porosity (>89 %) and tunable magnetic properties exhibit a unique three-dimensional bicontinuous ligament-channel Ag network with embedded Ni microparticles, as well as good hydrophilicity. Combined with the synergistic light absorption of the bimetal Ag and Ni, the NP-AgNi films exhibit good broadband absorption over the 200–2500 nm wavelength. More importantly, the NP-AgNi films show excellent SSG performance (evaporation efficiency over 89 %, evaporation rate ≥ 1.42 kg·m−2·h−1 and good cycling stability) under one sun irradiation. Additionally, the NP-AgNi films show outstanding seawater desalination and dye wastewater purification capability. This work provides an inspiration for the design and fabrication of multi-functional metal-based photothermal films in solar water treatment.

Fabrication of lanthanum-silane film by electrochemically assisted sol–gel method for enhanced corrosion resistance of sintered NdFeB

Fabrication of lanthanum-silane film by electrochemically assisted sol–gel method for enhanced corrosion resistance of sintered NdFeB

Making aerogel films like playing LEGO: A universal fabrication strategy for Kevlar based aerogel films with arbitrarily designed functions

Highly flexible, ultrathin and mechanically robust aerogel films activated by functional nanofillers exhibit tremendous potentials for wide applications. However, it is difficult to design different functionalities in a single aerogel film, as different nanofillers often possess opposing properties. Herein, a LEGO®-inspired fabrication strategy to construct Kevlar-based aerogel film with arbitrarily designed functions is introduced by stacking functionalized aerogel film units as stacking LEGO® bricks. The aerogel film units are reliably connected by precursor dispersion-derived LEGO® embossed nodes, leading to superior mechanical strength. Moreover, owing to the flexibility of the LEGO®-inspired assembly method, targeted functions of the aerogel films can be achieved by designing and purposefully combining various stacks. As demonstrations, optimized joule heating, greatly enhanced electromagnetic wave shielding and excellent flame-retardant properties are realized with stacking of different aerogel film units. The unique fabrication strategy opens up opportunities for the design and fabrication of aerogel film with tunable and tailored properties for wide applications.

Phenyl-C61-butyric acid methyl ester (PCBM) Nanoparticle Mediated Boasting of Photoelectrochemical and Photocatalytic Properties of Bismuth Vanadate/lead sulphide (BiVO4/PbS) Composite Thin-Film

This work delineates the fabrication and characterization of BiVO4/PbS and BiVO4/PCBM/PbS-based composite heterostructure for visible-light-driven applications, such as pollution remediation, photoelectrochemistry (PEC), and applied bias to photoelectrochemical hydrogen generation efficiency (ABPE). The heterostructured composite was synthesized by a combination of Spin coating (for bismuth vanadate - BiVO4 thin film fabrication and PCBM deposition), and Successive Ionic Layer Absorption and Reaction -SILAR (for lead sulphide - PbS deposition) method and characterized using UV-visible Spectroscopy, time-resolved photoluminescence spectroscopy (TRPL), field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and photoelectrochemistry (PEC) analysis (PEC). The key benefit of incorporation of PCBM nanoparticles in BiVO4/PCBM/PbS was realized through 1) ∼ 70% improvement in the photocurrent density during electrochemistry analysis, 2) ∼ 2.3 times enhancement in ABPE, and 3) ∼ 43% enhancements in ‘rate constant’ towards photocatalytic (methylene blue) degradation compared to BiVO4/PbS. The work shows the benefits of the PCBM-conductive carbon-based electron transport layer as a bridge between two inorganic semiconductors (BiVO4 and PbS) towards enhancing fast electron separation and transport at the interface during visible light irradiation.