Preparation Of Thin Films Research Articles

Tailored Nanoarchitectures: MoS₂/Graphene and MoS2/Graphene Oxide Thin Films via Liquid-Liquid Interfacial Route.

The nanostructured assembly of different two-dimensional (2D) materials in specific organization is crucial for developing materials with synergistic properties. In this study, we present a general methodology to prepare thin, transparent and self-assembled films of 2D/2D composites based on molybdenum sulfide (MoS2)/graphene oxide (GO) or MoS2/reduced graphene oxide (rGO), through the liquid/liquid interfacial route. Different nanoarchitectures are obtained by changing simple experimental parameters during the thin film preparation steps. The films were characterized by UV-Vis and Raman spectroscopy, scanning electron microscopy and cyclic voltammetry, evidencing that the experimental route used plays a role in the organization and properties of the assembled nanoarchitectures. Likewise, nanostructures of MoS2/GO and MoS2/rGO prepared through the same route have different organizations due to the different interactions between the materials. This showcases the potential of the technique to prepare tailored nanoarchitectures with specific properties for various applications, paving the way for innovative nanotechnology and materials science applications.

The enhancement in microstructure, optical and electromagnetic shielding properties of Al-doped Ag thin films by annealing treatment

Ag thin films having attractive optical transmittance and effective shielding capability are usually used as a preferred choice for the transparent electromagnetic shielding windows. Whereas, the Ag films are grown primarily via an island growth (Volmer-Weber) mechanism, which greatly restricts its application. In this study, by introducing Al atoms and suitable annealing treatment, the continuous and smooth Ag thin films are successfully fabricated by magnetron co-sputtering method. The effect of annealing temperature on the microstructure, optical and electromagnetic shielding properties of the films are conducted the comprehensive and profound study. Our results indicate that the 5 mol% Al-Ag thin film annealed at 200 °C could transform into planar growth structure, and display excellent the highest optical transmittance 89.15% at 550 nm. Meanwhile, the shielding effectiveness (SE) reaches a peak value of 28.1 dB. 500°C is estimated as the threshold annealing temperature of Al-Ag thin film with comprehensive performances gradually declining. Moreover, the Al dopants significantly improve the thermal stability of Ag thin films than that of the pure Ag films. These findings are of important guidance for the preparation of high-quality Al-Ag thin films to meet the practical applications.

Lithium and sodium ion Co-doping: A promising strategy for enhancing the performance of Cs2AgBiBr6 perovskite solar cells

The non-toxic perovskite Cs2AgBiBr6 presents impressive photovoltaic performance and stability, offering a lead halide-free alternative for solar cells. Overcoming challenges related to thin-film preparation and its intrinsic indirect bandgap, we leverage the synergistic effect of co-doping with lithium ions (Li+) and sodium ions (Na+) to enhance perovskite solar cells (PSCs). Improved carrier transport in Cs2AgBiBr6 films, facilitated by the diffusion of Li+, significantly enhances the photovoltaic conversion efficiency (PCE). Systematic exploration of various doping ratios identifies the optimal co-doping ratio, resulting in a remarkable PCE increase to 5.02 % and a short-circuit current of 6.56 mA cm−2. Ion doping not only tunes the material's band gap but also adjusts the energy level arrangement within the device layers. Impressively, the PCE of co-doped PSCs experiences only a 16.8 % decline after 60 days in an unencapsulated environment, underscoring its outstanding stability. This work provides a rational design for double-ion co-doping experiments, enhancing PSC performance and offering valuable insights for the future development of PSCs.

Two-Dimensional (2D) Conductive Metal-Organic Framework Thin Films: The Preparation and Applications in Electrochemistry.

Two-dimensional conductive MOF thin films have attracted attention due to their rich pore structure and unique electrical properties, and their applications in many fields, including batteries, sensing, supercapacitors, electrocatalysis, etc. This paper discusses several preparation methods for 2D conductive MOF thin films. And the applications of 2D conductive MOF thin films are summarized. In addition, the current challenges in the preparation of 2D conductive MOF thin films and the great potential in practical applications are discussed.

Preparation of Polycarbazole and Polyaniline Conducting Thin Films and Coating on Indium Tin Oxide by Spin Coating, Dip Coating and Drop Casting

Conducting polymers such as polyaniline (PANI), polycarbazole (PC) and polythiophene (PT) have gained attraction among researchers owing to their outstanding electrical and optical properties. In present study, polyaniline (PANI), polycarbazole (PC) and polythiophene (PT) were prepared by oxidative chemical polymerization followed by their characterization using techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and Raman spectroscopy. The synthesized polymers were further coated with indium tin oxide (ITO) using three different methods viz. spin coating, dip coating and drop casting. The thickness of the films was measured using a Stylus Profilometer and found to be 400 nm for PC and 500 nm for PANI and PT. Therefore, it can be concluded that using suitable process parameters, thin films can be easily obtained from conducting polymers, thus opening new avenues in their application towards sensors, supercapacitors and optoelectronic devices.

High-performance Bi2S3 photodetector based on oxygen-mediated defect engineering and its wafer-scale fast fabrication

Bi2S3 with a 2D van der Waals structure has attracted much attention due to its high conductivity, large absorption coefficient, and environmental friendliness. The preparation of tunable optoelectronic devices can be realized by exploiting and tuning Bi2S3 intrinsic defects. In this work, a simple and rapid method for the preparation of bismuth sulfide thin films and successfully prepare Bi2S3 with sulfur vacancies (Svac) (LA-Bi2S3) and oxygen passivated (Svac) (AP-Bi2S3) was presented. The defect state difference of the two devices leads to exhibit different optoelectronic properties. Under 638 nm and 1310 nm illuminations, the LA-Bi2S3 photodetectors exhibit responsivities of up to 2250 and 3.6 mA/W and detectivities of 1.69 × 1012 and 2.6 × 109 cm·Hz1/2 W−1, while the AP-Bi2S3 photodetectors have ultra-fast on/off speeds of 1 ms and 8 ms, and on/off ratio up to 3 × 103. The preparation method of the tunable optoelectronic devices gives a new avenue for defect tuning in metal sulfides and for the preparation and application of optoelectronic devices.

Preparation and Performance of Ce-Doped V2O5 Thin Films Deposited on FTO Substrates

Preparation and Performance of Ce-Doped V2O5 Thin Films Deposited on FTO Substrates

Preparation and Characterization of Nanostructured ITO Thin Films by Spray Pyrolysis Technique: Dependence on Annealing Temperature

Transparent conducting oxides (TCOs) like Indium tin oxide (ITO) have wide attention from all scientists which have low resistance and high visible light transmittance, used as transparent electrodes in many optoelectronic devices such as liquid crystal displays, touch screens, light emitting diodes, and solar cells. In this research, the relationship between the crystallization, optical transmittance, and surface roughness of nanostructured ITO thin films and the change in annealing temperature was investigated. To enhance the efficiency of this material in optoelectronic applications, both the optical transmittance in the visible region and the crystallite size must be increased. These results can be obtained by the heat treatment of the films. Nanostructured ITO thin layer films have been successfully prepared at a substrate temperature equal to (350)℃ by chemical spray pyrolysis (CSP) technique. The physical characterizations of nanostructured ITO thin layer films were investigated at different annealing temperatures (400,450 and 500)℃. The presence of diffraction peaks indicates that the as-deposited and post annealed films are polycrystalline cubic structure and the peak (400) is a preferred growth orientation. For all samples the value of intensity of diffraction peaks increases with increasing substrate temperature. The crystallite size of nanostructured ITO thin films is strongly related to the annealing temperature. The crystallite size estimated from XRD was found to rise with rising annealing temperature. The surface roughness of nanostructured ITO thin layer films increases with rising annealing temperature. High values of transmittance have been measured in the visible region 550 nm equal to (70, 82, 84 and 88)% corresponding to annealing temperature (350,400,450 and 500)℃ respectively.

Multiscale Models of CVD Process: Review and Prospective.

Chemical vapor deposition (CVD) is a crucial technique in the preparation of high-quality thin films and coatings, and is widely used in various industries including semiconductor, optics, and nuclear fuel, due to its operation simplicity and high growth rate. The complexity of the CVD process arises from numerous parameters, such as precursor chemistry, temperature, pressure, gas flow dynamics, and substrate characteristics. These multiscale parameters make the optimization of the CVD process a challenging task. Numerical simulations are widely used to model and analyze the CVD complex systems, and can be divided into nanoscale, mesoscale, and macroscale methods. Numerical simulation is aimed at optimizing the CVD process, but the inter-scale parameters still need to be extracted in modeling processes. However, multiscale coupling modeling becomes a powerful method to solve these challenges by providing a comprehensive framework that integrates phenomena occurring at different scales. This review presents an overview of the CVD process, the common critical parameters, and an in-depth analysis of CVD models in different scales. Then various multiscale models are discussed. This review highlights the models in different scales, integrates these models into multiscale frameworks, discusses typical multiscale coupling CVD models applied in practice, and summarizes the parameters that can transfer information between different scales. Finally, the schemes of multiscale coupling are given as a prospective view. By offering a comprehensive view of the current state of multiscale CVD models, this review aims to bridge the gap between theory and practice, and provide insights that could lead to a more efficient and precise control of the CVD process.

Sulfuration-induced enhancement of photodetection performance of photoconductive detector based on Bi2O2Se thin film

Significant interlayer transmission obstacles and numerous interface barriers in two-dimensional material thin films impede charge transfer, degrading device performance. However, appropriate impurity ions can enhance charge mobility by creating transfer channels and regulating interface defect states. Herein, a series of Bi2O2SxSe1-x films were prepared by a one-step hydrothermal sulfurization method. The XRD and XPS measurement and analysis can confirm that the Se atoms have been replaced by the S atoms. The introduction of S atoms can effectively enhance the number of defects in Bi2O2Se, resulting in an increase in carrier concentration, thereby improving the conductivity of Bi2O2Se film. The photoconductive detectors fabricated from these Bi2O2SxSe1-x films showed improved detection performance compared to those made from the pristine Bi2O2Se film, and the responsivity is increased by nearly 1000 times. Notably, the detector based on Bi2O2S0.37Se0.63 film has high responsivity (47.7 mA/W) and fast response time (15 ms/25 ms). The simple thin film preparation method and good device performance make it have great potential for large-scale preparation.

A HYBRID MEREC-TOPSIS APPROACH FOR THE IMPROVEMENT OF PHYSICAL VAPOUR DEPOSITED TITANIUM CARBO-NITRIDE COATING

Titanium carbo-nitride (TiCN) comes under the metal nitride group which can provide a combined property of titanium carbide (TiC) and titanium nitride (TiN) coating. TiCN Coating possess an excellent mechanical and tribological, properties which leads its application in many industries particularly in the Automotive and aerospace industries. TiCN films can be very hard and strong based on the composition and synthesis process. Physical Vapor Deposition (PVD) technique is widely used for the preparation of thin film coating because of its ability to precisely control the composition and thickness of the coatings. The properties of the developed coating significantly affect by the PVD process parameters and their levels. Multi-Criteria Decision Making (MCDM) methods are widely used in many sectors for the selection of process parameters based upon some specific criteria. In the present work TiCN coatings were synthesized by using one of the most widely used PVD method called magnetron sputtering. L16 orthogonal array was used as a design of experiment for the experimental work by varying the sputtering process parameters like bias voltage, N2 flow rate and substrate to target distance. After the synthesis, the developed films were tested using atomic force microscopy (AFM), Scanning electron microscopy (SEM), and Nanoindentation. From the characterization three response parameters such as hardness (H), Modulus of elasticity (E) and surface roughness (Ra) of the coating has been considered. A hybrid method based on improved removal effects of criteria- technique for order performance by similarity to ideal solution (MEREC-TOPSIS) approach has been considered for the for the process parameters selection. The results have also been compared with other weight calculation techniques. In all the cases it is observed that experiment no 16 and 15 have got the 1st and second rank respectively. However, experiment no 1 is the last rank in all the cases. From the correlation analysis it is found a strong positive correlation between MEREC-TOPSIS and other methods. The method provides a significant advancement in the selection of optimal parameters, ensuring enhanced coating properties crucial for industrial applications.

Study on the suppression of secondary electron emission characteristics based on TiN

Abstract With the continuous development of satellite communications, the problem of high-frequency high-power multipactor caused by the miniaturization of microwave passive components in the aerospace field has become more and more serious. In this paper, for the problem of multipactor suppression of load passive devices, we carried out research on the preparation of TiN thin films based on PEALD and put forward a new method for suppressing SEE with good suppression effect, high consistency, low surface resistance, and other aspects of the unity of the multipactor effect. The use of 20nm TiN coating can make the silver-plated surface secondary electron emission coefficient down to 1.59. The RF surface resistance change rate is less than 3%. In the field of communication, satellite and navigation and other fields have a wide range of application prospects.

Structural, Morphological, and Optical Properties of TiO2/CdS Core-Shell System Prepared by Two Method for Photoelectrocatalytic Application

Abstract The present study utilized the hydrothermal technique to carry out the deposition of films of TiO2. The deposition of CdS on the TiO2 films was accomplished using the chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR) methods. The morphological and structural characteristics of the TiO2/CdS thin films were investigated using a combination of XRD, SEM, EDX, and AFM techniques. Additionally, the optical properties of the nanostructures were examined using UV-Visible and PL spectroscopic techniques. The X-Ray Diffraction pattern of all TiO2 films revealed the formation of the anatase phase. The CdS present in the Ti/TiO2/CdS samples exhibited a hexagonal structure. The hydrothermal technique employed in the preparation of the TiO2 thin films resulted in the formation of nanofiber morphology, which was evident from the SEM images. The absorption edge data for the TiO2/CdS films demonstrated a shift towards the visible region, indicating a decrease in the bandgap as compared to the TiO2 nanostructure. Significantly improved photoelectrocatalytic performance was observed in the Ti/TiO2/CdS samples prepared using the CBD method, surpassing that of the Ti/TiO2/CdS samples prepared using the SILAR method.

Lanthanum doped hafnium oxide thin films deposited on a lateral high aspect ratio structure using atomic layer deposition: A comparative study of surface composition and uniformity using x-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry

Hafnium oxide (HfO2) thin films doped with lanthanum (La) can achieve ferroelectricity, making the material applicable in transistor and memory technologies. To downscale future devices in the semiconductor industry, the application of the doped HfO2 material requires deposition on complex microscopic three-dimensional (3D) structures. A widely used process for the preparation of doped HfO2 thin films is atomic layer deposition (ALD). With 3D geometries, it is challenging to deposit materials homogeneously and to effectively characterize them. To forego the difficulties in film characterization, two-dimensional (2D) PillarHall lateral high aspect ratio (LHAR) test structures are used. These structures expose a lateral surface to facilitate the conformality analysis of thin films deposited using two different ALD processes. In this work, we aim to further advance the arsenal of analysis techniques used to characterize La doped HfO2 thin films by using x-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) to analyze uniformity and composition. The XPS technique can be applied and established as a method for the optimal analysis of thin films deposited on LHAR structures. Both techniques provide a complementary analysis of material formation, elemental distribution, measurement along the LHAR depth range, and can probe differences between deposition processes.

50 MeV Li- and 80 MeV Ni- ions induced modification in ZnO cauliflower like structure: Structural, optical and electrical studies

In this work, ZnO has been synthesized by co-precipitation method and mixed with 0.5 % of polyvinyl alcohol for the preparation of thin film. These ZnO thin films have been irradiated with lithium (Li) and nickel (Ni) beams of energy 50 MeV and 80 MeV respectively, at different fluence. XRD pattern reveals that the crystallite size varies from 41 nm to 21 nm for Li-irradiated ZnO and to 16 nm for Ni irradiated ZnO compared to pure ZnO. From UV–Visible spectroscopy, the bandgap of Li-irradiated ZnO to a fluence of 5 × 1012 ions/cm2 is found to be 3.20 eV However, for Ni-irradiated ZnO bandgap varies from 3.11 to 3.08 eV Upon investigation of PL spectra, it has been observed that broadening in the defect region is observed on increasing the Li fluence. However, Ni-ions lead to enhancement of defects with increase in fluence. Electrical properties reveal the enhancement of current in order of three for both the ions irradiated ZnO. Li irradiation leads to reduction in resistivity whereas Ni irradiation leads to the enhancement in ZnO resistivity. This suggests that the ion beam induced modification in ZnO lattice could be useful for tuning the optoelectronic properties & can be used for organic light emitting diodes.

Surface treatment processed electron transport layers for efficient Sb2S3 solar cells

Solution-processed Sb2S3 thin films and solar cell devices have recently gained popularity due to their easy procedure and outstanding final device performance. Nevertheless, although the substrate has a significant influence on thefollowing functional films, the effect of the substrate in the Sb-based solar cells appears to have not been adequately examined. In this study, we performed an interesting thioacetamide (TA)-assisted surface treatment strategy on the electron transport layer (ETL) to achieve high-quality development of Sb2S3 thin films and based solar devices. The surface treatment of ETLs resulted in a uniform surface, Zn(OH)2 impurity reduction, and excellent wettability. The above enhanced the growth of Sb2S3 thin films with features like extremely large crystal sizes (∼8 um), more homogeneous and dense film morphology, preferred crystal orientation, reduced oxygen content, and fewer defects, which benefits carrier transport. Finally, a device structure constructed of FTO/TiO2/Zn(O,S)/Sb2S3/Spiro/Au was created, resulting in an almost 30 % increase in efficiency, from 4.05 % to 5.21 %. The proposed approach not only gives new insights into generating higher-quality Sb2S3 thin films and devices, but it also presents new concepts and methods for future high-quality sulfide thin film preparation.

Preparation of CdTe thin films using seed method

Preparation of CdTe thin films using seed method

Preparation and optical characterization of 3D-TiO2 thin films with brilliant colors

In this paper, three-dimensional titanium dioxide (3D-TiO2) thin films with periodic structure were obtained by periodic pulse anodization of high-purity titanium wafers under specific alternating voltage (AV) using asymmetric sawtooth waveforms. The effect of voltage amplitude and electrolyte concentration on the structural color of the 3D-TiO2 thin films were investigated. It is shown that the nanotubes grown by asymmetric sawtooth wave at a specific AV have a “bamboo” shape, and the cycle length, as well as the inner and outer tube diameters of the nanotubes are closely related to the AV. The structural color of the samples was different at varying voltages and electrolyte concentrations for the same oxidation cycle time. The structural color of films grown under low voltage is analyzed to be related to the scattering and absorption of light on their surfaces. The thickness of the film grown under high voltage satisfies the conditions for light interference. The maximum reflected wavelength is red-shifted and then blue-shifted as the electrolyte concentration decreases. The study shows that the microstructure is the main influence on the color change of 3D-TiO2 thin films.

Preparation and Photodegradation of TiO2 Thin Films on the Inner Wall of Quartz Tubes.

Titanium dioxide thin films on the inner wall of quartz tubes were prepared in situ by the sol-gel method. Meanwhile, copper and cerium were loaded onto the surface of the titanium dioxide thin films to enhance photocatalytic activity and broaden the range of light absorption. X-ray diffractometer, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectrum, N2 gas adsorption, UV diffuse reflectance spectroscopy, electron paramagnetic resonance, photoluminescene spectroscopy, and so on were used to characterize the structure, morphology, chemical composition, and optical properties of the prepared photocatalyst. Methylene blue (MB) was used as a simulated organic pollutant to study the photocatalytic performance of the photocatalyst, which was a translucent, structurally stable, and reusable high-efficiency photocatalytic catalyst. Under UV lamp irradiation, the MB photodegradation efficiency was 94.5%, which reached 91.2% after multiple cycles.

Boosting deep-ultraviolet photodetector performance via ferroelectric effect based on HfAlOx@PEI composite

In this study, hafnium-aluminum oxide (HfAlOx) was used as an effective active layer in a self-powered deep-ultraviolet (UV) photodetector. For the first time, we exploited the ferroelectric properties of crystalline HfAlOx to enhance device performance. The HfAlOx powder obtained at an annealing temperature of 850 °C exhibited the highest-intensity peak for the orthorhombic phase (o-phase), representing the ferroelectric property of the material. The HfAlOx particles were reduced to a small size using mechanical treatment to facilitate the preparation of a composite thin film with a polyethyleneimine (PEI) polymer matrix. First, the HfAlOx@PEI composite film-based photodetector demonstrated a remarkable on/off ratio of more than 103 and a rapid response (trise/tfall of 0.127/2.7 s) at zero bias under 254-nm UV illumination. Second, the photocurrent of the device was dramatically boosted under an external bias owing to the injection of carriers, supported by the ferroelectric effect of the o-phase HfAlOx. As a result, the external quantum efficiency and responsivity approached 2628 % and 5.37 A/W at −1 V bias, respectively. Furthermore, the device exhibited excellent photostability, demonstrating almost no change in the photocurrent after 1000 s of UVC irradiation. Our findings provide guidance for the preparation of optoelectronic devices, particularly self-powered high-performance UV photodetectors.