Synthesis Of Thin Films Research Articles

Synthesis, analysis, and characterizations of microspherical MoO3 thin films for energy storage

Synthesis, analysis, and characterizations of microspherical MoO3 thin films for energy storage

Enhanced hydrogen gas sensing characteristics of CuO/ZnO heterojunction for thickness-dependence and its application

In this study, we experimentally verified the synthesis of ZnO and CuO thin films using a droplet-based hydrothermal method and their hydrogen sensing performance. The hydrogen gas detection performance of the fabricated heterostructured gas sensor was evaluated based on the results of an experiment conducted while controlling the temperature and hydrogen concentration in the gas chamber. According to the responses of single metal oxide sensors made of each ZnO and CuO and their heterojunction sensors, CuO deposited with 7 cycles on 5 cycles of ZnO had a resistance change rate of about 164 % and the change of the resistance took 3 s in the environment of 4 % hydrogen at 300 °C. This sensor showed the highest response rate and fastest reaction time out of all. CuO/ZnO showed the highest reaction at 300 °C, confirming its selective reaction to hydrogen. To solve the problem of metal oxide-based gas sensors with low selectivity, the operating principle of the heterojunction between metal oxide that has selective gas reactivity was analyzed and experimentally verified. Additionally, the fabricated sensor was confirmed to have selective responsiveness to different gases at various temperatures. Using these characteristics, it was confirmed that this heterostructure based sensor can be used as a sensor array for electronic nose that could classify unknown gases using the same sensor at various temperatures.

Chemical bath deposition-based synthesis of tin sulfide on silicon substrate and its application as a photodetector

Tin sulfide (SnS) is an attractive compound semiconductor for photovoltaic and sensing applications because of its abundance and non-toxicity. In the present work, the synthesis of SnS thin films on silicon substrates by chemical bath deposition (CBD) technique has been demonstrated. Tin chloride (SnCl2.2H2O) and thiourea were used as the tin and sulfur sources to deposit the SnS films with triethanolamine (TEA) as the complexing agent and sodium hydroxide (NaOH) as alkaline bath. To understand the growth mechanism, a time interrupted growth series was adopted at a temperature of 90 °C for different time durations i.e., 60 min, 120 min, and 180 min. A photosensor was fabricated using the SnS/Si heterojunction and its performance was investigated through electrical (current-voltage) and optical (photo-response) measurements. The I–V characteristics of the developed photodetector were recorded under dark and different light intensities. The device exhibited significant response to light even without a bias voltage.

Deposition of Sn-Zr-Se precursor by thermal evaporation and PLD for the synthesis of SnZrSe3 thin films

Background ABX3 (X=Se, S) chalcogenides are an emerging class of materials for sustainable photovoltaics. Among ABX3 materials, BaZrS3 has gained the highest community interest. BaZrS3 is the wide bandgap absorber (> 1.7 eV) and therefore is intended for application as a top sub-cell in multijunction devices. However, narrow band gap ABX3 compounds have drawn little attention although this could potentially open the path for fabrication of multijunction solar cells based entirely on ABX3 materials. SnZrSe3 is a narrow bandgap semiconductor with an absorption edge located at around 1.0 eV, but there are no reports on the formation of SnZrSe3 thin films thus far. In this work, therefore, we aim to obtain SnZrSe3 thin films by sublimation methods. Methods Thermal evaporation and pulsed laser deposition (PLD) techniques were used to deposit Sn-Zr-Se precursor films. SnZrSe3 powder was synthesized and used as a source material for evaporation and PLD target preparation. Precursor films were deposited by PLD from single-phase and binary selenide targets. Results We found that using SnZrSe3 powder, only SnSe films were deposited under various conditions by thermal evaporation. Precursor films obtained by PLD from single-phase targets were amorphous and comprised SnSe2 and a-Se phases whereas using binary targets crystalline SnSe and a-Se were detected. Thermogravimetric analysis revealed that SnZrSe3 was thermally stable up to 450 °C and afterwards decomposed into SnSe, Se and ZrSe2-x. Conclusions Using methods described in this work, we were not able to achieve congruent sublimation of SnZrSe3 because of the following reasons: (i) upon energetic excitation, SnZrSe3 decomposes into compounds with very different vapour pressure; (ii) inability to substitute O with Se due to very high chemical affinity of Zr and O. Direct sublimation methods are challenging for formation of SnZrSe3 thin films and other techniques, such as co-evaporation should be explored.

Sol–Gel Synthesis of Nanostructured Mesoporous Silica Powder and Thin Films

Mesoporous materials are special nanoporous materials containing well-defined mesochannels with a pore diameter between 2 and 50 nm. The high surface area, ordered structure, tunable pore size, and easiness of functionalization have made mesoporous silica powder and thin films interesting materials for a wide range of applications including drug delivery, absorption, separation, catalysis, energy conversion, and storage. The sol–gel process has emerged as a promising technique for the synthesis of nanostructured mesoporous silica materials as it provides the advantages of low-temperature processing and easy control of the synthesis parameters. Although it offers several advantages over other synthesis techniques, it also has the drawbacks of high sensitivity to processing conditions. Hence, this review paper aims to give critical insights into the sol–gel process, the chemistry of sol–gel silica, the formation mechanism of mesoporosity, and the effects of the reaction parameters. A good understanding of these phenomena is essential to better control and optimize the properties of the final material for specific needs and applications. Additionally, this review paper discusses the different methods applied to the synthesis of nanostructured ordered mesoporous thin film silica, including the Electrochemically Assisted Self-Assembly method of synthesis. The EASA method is a novel and promising technique for the synthesis of well-ordered and vertically aligned pore channels of mesoporous thin films as it is required for mass transport applications. Moreover, the effects of sol composition, pH, applied potential, and deposition time on the final thickness of the thin film are elaborated on in detail. Furthermore, this comprehensive review highlights the potential and opportunities for future research and development in the area to further advance and use its full potential advantages.

High thermoelectric performance in polycrystalline Yb3Ge5 thin films

The development of eco-friendly thin-film thermoelectric generators for microenergy harvesting applications is highly desired. Ge-based materials have recently attracted significant research interest because of their superior performance at room temperature as human-compatible thermoelectric constituents. We examined the synthesis of Yb3Ge5 thin films and assessed their thermoelectric properties, considering the exceptional ability of Yb as a heavy metal to scatter phonons. The components of the resulting thin film were strongly dependent on the Yb/Ge deposition ratio and the subsequent annealing temperature. An increase in the Yb content augmented the formation of Yb2O3, whereas an increase in the Ge content facilitated the formation of Ge crystals. These trends were more evident at higher annealing temperatures. By controlling the YbGe composition, a power factor of 1470 µW m−1 K−2 was obtained at an annealing temperature of 700 °C, along with a low thermal conductivity of 3.1 W m−1 K−1. Machine-learning-facilitated data analysis revealed that the high power factor originated from Yb3Ge5. Notably, the power factor reached 1370 µW m−1 K−2 even at a temperature of 500 °C, causing the expansion of heat-resistant plastic films. Thus, we established the impressive potential of Yb3Ge5 as a suitable material for eco-friendly thin-film thermoelectric generators.

Synthesis of Cu2CoSnS4 chalcogenide thin films by spray pyrolysis and efficient Au/p-CCTS/n-SnO2 diode for cells solar applications

Synthesis of Cu2CoSnS4 chalcogenide thin films by spray pyrolysis and efficient Au/p-CCTS/n-SnO2 diode for cells solar applications

Investigation of the Effects of Different H2SO4, HCI, HNO3 and HCIO4 Liquid Acid Media on the Synthesis of CdTe Semiconductor Thin Films for Solar Cells

The main target of the present paper is to investigate the effect of different acidic aqueous media(DAAM) on the synthesis of cadmium telluride thin films(CdTeTFm). The synthesis of CdTeTFm was carried out by the electrochemical deposition method(EDM) in DAAM. The chronoamperometry method of electrodeposition(ED) was used for the production of CdTeTFm. Furthermore, the electrochemical behaviors of the solutions were studied using cyclic voltammetry. The experiments were carried out with 3 electrodes (a working electrode (WE), a reference electrode(CE), and a counter electrode(RE)) using the electrochemical cell potentiostatic method. The experimental conditions of the acidic aqueous CdTe solution have been determined to be pH 3.56-3.57, the temperature of the solution is 85°C, the concentration of CdTe 2.45x10-1 M, and the reaction time is 25 minutes. The physical properties of CdTeTFm were determined by XRD, SEM/EDX, FT-IR, and UV-VIS analysis methods. According to the results of the analysis, it was observed that acidic aqueous media have an important role in the synthesis of CdTeTFm. The bandgap ranges and Cd/Te ratios of the synthesized thin films were obtained as 1.42, 1.48, 1.50, 1.58 eV, 0.65, 0.587, 0.79 and 0.738, respectively.

Synthesis and characterizations of Ce-doped ZnO thin films for radiation shielding

In this research, different amounts of Ce-doped ZnO thin films were synthesized using the spray pyrolysis method. Structural, morphological and optical properties of these synthesized films were investigated. In XRD analyses, wurtzite (hexagonal) structures were observed in the films. In SEM analysis, there were changes in the surface morphology of the films with doping, and in cross-section measurement, the thickness of the films was measured to be approximately 1.2 μm. In UV–vis spectrometry analysis, it is seen that the effect of Cerium contribution on optical transmittance and band gap positively affects shielding. NaI(Tl) detector and gamma energies of 384, 1173, and 1333 keV have been used to investigate the radiation protection properties of these synthesized films. As a result of these measurements, linear attenuation coefficient (LAC) values have been obtained. Radiation shielding parameters have been calculated with these (LAC) values. The Mass Attenuation Coefficient (MAC), Half Value Layer (HVL), Tenth Value Layer TVL (and) Mean Free Path (MFP) values have been also calculated using this LAC result. According to these results, Ce-doped ZnO films were found to be effective in radiation shielding.

Synthesis and characterization of Mo-doped PbS thin films for enhancing the photocatalytic hydrogen production

Photocatalytic hydrogen production has gained considerable attention as a sustainable method for renewable energy production. Lead sulfide (PbS) compound has significant reserves and a suitable bandgap for the production of hydrogen gas via the water photo-splitting process. However, the charge recombination effect of the charge carriers severely limits their potential use in solar water splitting. Herein, the photoelectrodes of PbS were fabricated through the chemical bath deposition method and then doped with different Mo concentrations to optimize the hydrogen photo-production activity. Both structural and performance characterizations of the photoelectrodes have been carried out using various characterization techniques. The photoelectrochemical (PEC) performance of molybdenum (Mo)-doped PbS photoelectrodes exhibits a significant increase in the photocurrent density with the optimum photocurrent density of 1.2 mA/cm2 obtained at 0.8 % Mo doping atomic ratio which was twelve times higher than that of a pure PbS photoelectrode. The doping of Mo induces the electron-hole separation yield which results in improved electron transport characteristics. The Mo doping was as act as a donor site that increased the PbS film conductivity. The newly optimized Mo–PbS was used as a promising photoelectrode supported on commercial glass using the optimum Mo-doped PbS photoelectrode, the photoelectrochemical (PEC) hydrogen production rate was reached 122 μmol/h cm2 during the solar water splitting process and the conversion efficiency of the incident photon-to-current (IPCE) value was 7.0 % at 390 nm monochromatic exposure. Moreover, the stability of the optimum electrode was evaluated as a function of the number of runs and exposure time in addition to the electrochemical impedance study.

Synthesis, thermal expansion and optical properties of ZrV2O7 thin films

Cubic ZrV2O7 thin films have been synthesized by sol-gel spin-coating method. The influences of annealing temperatures on the phase composition and morphology of ZrV2O7 thin films were investigated using XRD, SEM, and EDX. Negative thermal expansion (NTE) and optical performances of cubic ZrV2O7 thin films were analyzed using variable temperature XRD and UV–Vis spectroscopy. Results indicate that as-deposited ZrV2O7 thin films have an amorphous structure with smooth and dense surface. Cubic ZrV2O7 thin films were prepared after heat treatment at 720 °C for 1 h. It was found that the thin films contained V2O5 impurity with the Zr: V = 1:2 precursor solution. Pure cubic ZrV2O7 thin films were fabricated with the Zr: V = 1.75:2 precursor solution. Cubic ZrV2O7 thin films show isotropic NTE in the temperature range of 100–700 °C. The coefficients of thermal expansion (CTEs) of ZrV2O7 films along the a, b, and c axes are −6.88 × 10−6 °C−1, and the volumetric and linear CTEs are −20.56 × 10−6 °C−1 and -6.85 × 10−6 °C−1, respectively. The transmittance of cubic ZrV2O7 thin film is approximately 80 %.

Synthesis and characterization of Nd-doped CeO2 thin films grown by spray pyrolysis method: Structural, optical and electrochemical properties

In the present research, we successfully synthesized thin films of Cerium Oxide (CeO2) and Neodymium (Nd) doped CeO2 on both glass and ITO substrates using the chemical spray pyrolysis method. Their structural, morphological, optical and electrochemical properties were experimentally studied. X-ray diffraction analyses showed that all the layers exhibited the cubic fluorite phase characteristic of CeO2. Raman spectroscopy reveals a downward F2g band shift in all Nd3+-doped CeO2 films due to oxygen vacancies. The asymmetry and broadening of the Raman modes arise from the injection of Nd3+ ions in CeO2 thin films, which leads to variations in the presence of Ce3+ and oxygen vacancies. Additionally, the morphology of the films changes with different levels of Nd-doping. The UV–Vis-NIR spectra obtained in the wavelength scale between 300 nm and 1800 nm showed a noticeable reduction in the band gap from 3.46 eV to 3.30 eV. The cyclic voltammetry (CV) results indicate that the addition of Nd improves the ion storage capacities (ISC) of the cerium oxide thin film. Even after the intercalation/deintercalation of lithium ions, the doped cerium oxide thin films remain fully transparent. These significant findings broaden the potential applications of this oxide, particularly for electrochromic devices.

Two-Dimensional Conjugated Polymers: a New Choice For Organic Thin-Film Transistors.

Organic thin-film transistors (OTFTs) as a vital component among transistors have shown great potential in smart sensing, flexible displays, and bionics due to their flexibility, biocompatibility and customizable chemical structures. Even though linear conjugated polymer semiconductors are common for constructing channel materials of OTFTs, advanced materials with high charge carrier mobility, tunable band structure, robust stability, and clear structure-property relationship are indispensable for propelling the evolution of OTFTs. Two-dimensional conjugated polymers (2DCPs), featured with conjugated lattice, tailorable skeletons, and functional porous structures, match aforementioned criteria closely. In this review, we firstly introduce the synthesis of 2DCP thin films, focusing on their characteristics compatible with the channels of OTFTs. Subsequently, the physics and operating mechanisms of OTFTs and the applications of 2DCPs in OTFTs are summarized in detail. Finally, the outlook and perspective in the field of OTFTs using 2DCPs are provided as well.

Freestanding oxide membranes: synthesis, tunable physical properties, and functional devices

The study of oxide heteroepitaxy has been hindered by the issues of misfit strain and substrate clamping, which impede both the optimization of performance and the acquisition of a fundamental understanding of oxide systems. Recently, however, the development of freestanding oxide membranes has provided a plausible solution to these substrate limitations. Single-crystalline functional oxide films can be released from their substrates without incurring significant damage and can subsequently be transferred to any substrate of choice. This paper discusses recent advancements in the fabrication, adjustable physical properties, and various applications of freestanding oxide perovskite films. First, we present the primary strategies employed for the synthesis and transfer of these freestanding perovskite thin films. Second, we explore the main functionalities observed in freestanding perovskite oxide thin films, with special attention tothe tunable functionalities and physical properties of these freestanding perovskite membranes under varying strain states. Next, we encapsulate three representative devices based on freestanding oxide films. Overall, this review highlights the potential of freestanding oxide films for the study of novel functionalities and flexible electronics.

Room temperature synthesis of nanocomposite thin films with embedded Cs2AgIn0.9Bi0.1Cl6 lead-free double perovskite nanocrystals with long-term water stability, wide range pH tolerance, and high quantum yield

Cs2AgIn0.9Bi0.1Cl6 nanocrystals encapsulated with polystyrene or polymethyl methacrylate are described with high quantum yields, long luminescence lifetimes and water stability.

Synthesis of submillimeter-scale laterally-grown germanium monosulfide thin films and their electro-optic applications

Submillimeter-scale laterally-grown germanium monosulfide thin films and gate voltage-dependent hysteresis response of fabricated GeS field-effect transistor arrays.

Unveiling the Versatile Realm of CdSnO3 Nanoparticles for Advanced Sensing Applications

This study presents the synthesis and characterization of CdSnO3 thin films at different deposition temperatures 400, 500 and 600 °C. The prepared samples were characterized by XRD, FTIR, SEM, EDAX, TEM, optical and ammonia gas sensing properties respectively. X-ray diffraction confirms the orthorhombic crystal structure, with prominent peaks corresponding to the (111), (112), (103), (130), and (133) planes. The mean crystallite size is determined to be 84 nm. Scanning electron microscopy reveals morphological changes with varying substrate temperatures. Energy-dispersive X-ray spectroscopy shows elemental composition variations, highlighting non-stoichiometric CdSnO3 thin films. Transmission electron microscopy images depict larger spherical thin films with clear lattice fringes. Fourier-transform infrared spectra confirm the presence of Cd-O and Sn-O bonds. Optical properties yield a calculated band gap was decreased with increase in temperature. Gas sensing tests demonstrate significant sensitivity to ammonia gas concentrations, with responses affected by ammonia concentrations. Overall, CdSnO3 thin films show promise for applications in diverse fields due to their tunable properties and potential for tailored performance.

Условия закипания капель на поверхности тонкой плёнки оксида цинка при импульсном лазерном осаждении

The pulsed laser deposition (PLD) method is widely used in the production of different thin films. PLD has several advantages: flexible adjustment of parameters and controllability of processes and ease of synthesis of materials. The deposition of zinc oxide droplets during the synthesis of zinc oxide thin films by PLD is considered and the temperature and initial speed of droplets, which can boil on the thin film surface, are determined. The study of the process of the deposition of droplets from a ZnO target was carried out during the growth of thin films according to the traditional scheme for the PLD method. The process of the deposition of ZnO droplets during the PLD of ZnO films under vacuum conditions is considered. For the first time, it has been revealed that ZnO drops are boiling on the thin ZnO film surface. For the first time, the temperature and speed of solid and liquid drops of ZnO, at which they can boil when they hit the substrate, have been calculated taking into account the processes of heat loss through radiation and the heat of phase transition. Thus, for the first time, it has been established experimentally and confirmed in calculations that at the moment of collision some drops of ZnO are boiling. The role of the heat of phase transition and heat loss due to radiation during the flight of droplets during the PLD of ZnO thin films in a vacuum has been clarified. The temperature of a ZnO drop after a collision with a substrate was calculated in a wide range of initial speed and temperature taking into account heat losses due to radiation and heating from impact.

Wafer-scale synthesis of two-dimensional ultrathin films.

Two-dimensional (2D) materials, consisting of atomically thin layered crystals, have attracted tremendous interest due to their outstanding intrinsic properties and diverse applications in electronics, optoelectronics, and catalysis. The large-scale growth of high-quality ultrathin 2D films and their utilization in the facile fabrication of devices, easily adoptable in industrial applications, have been extensively sought after during the last decade; however, it remains a challenge to achieve these goals. Herein, we introduce three key concepts: (i) the microwave assisted quick (∼1 min) synthesis of wafer-scale (6-inch) anisotropic conducting ultrathin (∼1 nm) amorphous carbon and 2D semiconducting metal chalcogenide atomically thin films, (ii) a polymer-assisted deposition process for the synthesis of wafer-scale (6-inch) 2D metal chalcogenide and pyrolyzed carbon thin films, and (iii) the surface diffusion and epitaxial self-planarization induced synthesis of wafer-scale (2-inch) single crystal 2D binary and large-grain 2D ferromagnetic ternary metal chalcogenide thin films. The proposed synthesis concepts can pave a new way for the manufacture of wafer-scale high quality 2D ultrathin films and their utilization in the facile fabrication of devices.

Design, synthesis and characterization of hierarchical porous stacked thin films based on MOFs and ordered mesoporous oxides

Integration of mesoporous thin films and metal–organic frameworks as stacked bilayers, towards hierarchical porous 1D photonic crystals.