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Sprayed thin coatings of tin sulphide (SnS) onto glass substrates utilizing tin chloride dehydrate and CS (NH2)2 as precursors, in various substrate temperatures (250–325 °C) in steps of 25 °C. The physical properties were studied for all the as prepared SnS thin films. The increased substrate temperature on the film shows the increased crystallinity along orthorhombic nature of (040) plane. The Debye-Scherer formula was used to determine the crystallite's size, which ranged from 20 to 29 nm. The morphological, energy-dispersive X-ray spectroscopy (EDS) and 3D AFM micrographs were characterized to find the morphology and surface roughness of thin film. Optical transmittance spectra (500 nm–1100 nm) revealed that all films had direct band gap values with appropriate range of photo voltaic applications. In the FT-IR spectrum's absorption band, the characteristic stretching vibration mode of SnS thin films were analysed. The film developed at 325 °C had the lowest electrical resistivity of 4.28 Ω cm with a hole concentration of around 1013 cm−3. As the temperature of growth of the thin film increased, the resistance rapidly reduced. [ABSTRACT FROM AUTHOR]

V2VI3-based materials are the best materials for thermoelectric cooling devices. Interest in studying the transport properties of V2VI3 thin films has increased after it was found that V2VI3 belong to the class of topological insulators. In this work, the dependences of electrical conductivity, Hall coefficient, charge carrier mobility on magnetic field and temperature of Bi2(Te0.9Se0.1)3 films with thicknesses 48 and 130 nm were measured and interpreted. The transport properties in the thin-film and bulk states were compared. The boundaries between weak and strong magnetic fields were determined. The obtained results are important for solid-state physics development and practical applications. [ABSTRACT FROM AUTHOR]

In this article, work was carried out to optimize the thickness of the photoactive layer in inverted solar cells based on ZnO. Fluorine-doped tin oxide (FTO)/ZnO/P3HT:PCBM/MoO3/Ag organic solar cells were fabricated and characterized. The influence of the thickness of the photoactive layer on the morphology, optical and photoelectric properties of the solar cell has been studied. The surface topography of P3HT:PCBM was examined using atomic force microscopy (AFM). Increasing the thickness of the photoactive layer leads to an increase in the roughness of the film surface. Optical absorption spectra were measured. An increasing trend in absorption was clearly observed when moving from a thinner 85 nm film to a thicker 210 nm film. The P3HT:PCBM film thickness was optimized when deposited at various substrate rotation speeds, with the film produced at 500 rpm achieving a maximum photoconversion efficiency of 1.8%. [ABSTRACT FROM AUTHOR]

In this work, numerical simulations were employed to examine the influence of thickness and band gap energy of the Cu2ZnSnS4 (CZTS) absorber and Zn(O,S) buffer layer on the performance of the earth-abundant and nontoxic Mo/Cu2ZnSnS4/Zn(O,S)/i-ZnO/ZnO:Al structure. Firstly, simulation was performed on the CZTS-based solar cell with experimental values of thickness (610 nm) and band gap energy (1.51 eV) obtained for the absorber layer CZTS. We found an open-circuit voltage Voc = 1.17 V, a short-circuit current density Jsc = 23.26 mA/cm2, a fill factor FF = 57.31%, and a conversion efficiency η = 15.61%. Then we varied the thickness (from 500 nm to 3000 nm) and gap (from 1.40 eV to 1.60 eV) of CZTS thin film and concluded that the optimized thickness and band gap energy were 2400 nm and 1.48 eV, respectively. Finally, we used these values to found the optimal performance of the device. The optimized results were FF = 21.24%, Jsc = 28.05 mA /cm2, Voc = 3.63 V, and η = 21.64%. It is noted that the solar cell performance remained stable by varying the thickness and gap energy of the Zn(O,S) buffer layer. [ABSTRACT FROM AUTHOR]

Polycrystalline indium gallium oxide has been widely studied in the domain of oxide thin film transistors (TFTs) due to its high mobility. However, there are few researches focus on amorphous IGO (a‐IGO), which has the advantage of large area display. Herein, high‐performance a‐IGO TFTs are demonstrated by magnetron sputtering method with simple process. The efficiency of a‐IGO TFTs fabricated under various conditions are evaluated, and a‐IGO TFTs prepared by 27 nm thin films grown at 220 °C have the best electrical properties. It exhibits the mobility of 35 cm2 V−1 s−1, threshold voltage of 0.5 V, subthreshold swing of 0.8 V dec−1, and the on/off current ratio over 106. This is due to the precise control of the deposition energy state by temperature during sputtering and the influence of the semiconductor layer thickness on the distribution of the accumulation layer. The results present here demonstrate a simple fabrication method for high‐performance amorphous oxide TFT, providing a new option for display driver circuits. [ABSTRACT FROM AUTHOR]

This work employed the chemical bath deposition (CBD) technique to fabricate a thin layer of nanostructured MnO. According to XRD measurements, the films have a cubic crystal structure and are polycrystalline, with orientations of (111, 200, 311, and 222), with (200) being the preferred orientation. Although the dislocation density parameters (100.46 to 80.36) and strain decreased from 34.75 to 31.08 and 34.75 to 100.36, respectively, the grain size was largest at (200) nm film thickness and lowest at (300) nm thickness. The deposited films exhibited a smooth surface topography as evidenced by the average surface roughness dropping from 8.70 nm to 4.27 nm, the average particle size observed to be 82.8 nm to 39.2 nm, and a reduction in root mean square (rms) values from 6.82 nm to 3.09 nm in the AFM images. Nanostructured MnO films exhibit a variety of grain morphologies, polycrystalline structure, and uniformity in SEM images. Their optical properties were measured in the 300-900 nm wavelength range. The extinction coefficient ranged from 0.368 to 0.276, whereas the computed refractive indices of the films with varying thicknesses fell between 3.6 and 2.95. The transmittance ranged between 86 and 81% in the VIS-NIR region with a band gap between 3.24 and 3.13 eV, and it was found that the absorption and absorption coefficient increased with film thickness. The thickness of MnO reduces its sensitivity to H2S gas. [ABSTRACT FROM AUTHOR]

In these studies, radio frequency (RF) magnetron sputtering was used to produce nanostructured CuO thin films on glass bases with different thicknesses of (250, 300, and 350 nm). X-ray diffraction (XRD) analysis of these films revealed a polycrystalline structure with a preferred peak along the (111) plane. The Scherrer formula was used to compute the grain size. It was found that the average grain sizes are 10.78 nm, 11.36 nm, and 11.84 nm for film thicknesses of 250, 3000, and 300 nm, respectively, while the dislocation density and strain values decline. The surface roughness decreased from 9.30 nm to 4.71 nm as the thickness increased, according to atomic force microscopy (AFM) data. As the thickness of the film grew, the root mean square (RMS) roughness likewise decreased from 9.18 nm to 4.29 nm. The homogenous, semi-spherical structure comprises uniformly distributed particles, as demonstrated by SEM images. The optical properties of the grown films showed that the absorption coefficient considerably increased with film thickness. Transmittance, band gap, refractive index, and extinction coefficient all decrease with increasing film thickness. The hydrogen gas measurements, indicated a reduction in sensitivity as the thickness and gas concentration increased at 30°C. [ABSTRACT FROM AUTHOR]

Several contents of silicon in AlSi coatings, and substrate nature, were investigated in this present research. For this purpose, thin films were deposited by Physical Vapour Deposition onto three substrates: The effect of silicon content on the microstructure and mechanical properties of the coatings was studied. The microstructural observations showed that the coating carried out with 7 wt-%. silicon reduced the porosities by making the microstructures more homogeneous and denser. Also, the influence of substrate characteristics on the evolution and distribution of the microstructure formed during coating is important. Content of 13 wt-% eutectic enhanced the mechanical properties. The crystallite size evolves in a completely opposite way to that of the dislocation density and micro-deformation, with a minimum for the same values of silicon content (10–12 wt-%). The microstructural analysis allowed us to highlight the importance of silicon in the formation of intermetallic compounds. [ABSTRACT FROM AUTHOR]

This review aims to present a critical overview of indium tin oxide (ITO) thin film preparation methods, structure–property relationship, and its humidity sensing. A range of passive and active humidity sensors with thin films (based on metal oxides) detects humidity. ITO thin film has advantageous properties, such as low resistivity and high stability, making it highly suitable for humidity sensing applications. ITO thin film has shown the efficient level of humidity sensing, and a compatible size of humidity sensor can monitor the interface conditions humidity. So far, the application of ITO thin film for humidity measurement has yet to be explored at commercial scale, specifically in the detection of lower environmental humidity range (below 5% relative humidity (RH)). The research reveals a gap in improving the ITO thin film properties with an optimal range of preparation conditions. The research opportunities in the preparation, properties, characteristics, and efficient humidity sensitivity of ITO thin film are reviewed in this work. [ABSTRACT FROM AUTHOR]

The pursuit of low-power/low-voltage operation in devices has prompted a keen interest in the mesoscale effects within ferroelectric thin films. The downsizing of ferroelectrics can significantly influence performance; for instance, the remanent polarization and coercive field are susceptible to alterations based on thickness. In this study, randomly oriented Bi3.25La0.75Ti3O12 thin films were fabricated on Pt/Ti/SiO2/Si substrates using the sol–gel method, and SEM observations revealed rod-like grains in all thin films. The investigation delved into the correlation between dielectric and ferroelectric properties with thin film thickness. The thin film exhibited an increased remanent polarization and a reduced coercive electric field. Additionally, the ferroelectric domain structure was scrutinized through PFM, and the resistor properties of the BLT4 thin film were studied, which shows the potential of BLT thin films in non-volatile memory and memristor. [ABSTRACT FROM AUTHOR]

This study presents a comparison between spin-coating, dip-coating, and drop-coating that entails investigating the effect of the thickness on P3HT thin film properties. The grown P3HT thin films were characterized using a range of analytical techniques to evaluate their structural, morphological and optical properties. The XRD of P3HT thin films revealed strong thickness dependence where 30 nm thin film had low diffraction intensity and 148 nm thin film revealed the highest intensity. The nanoball morphology which varies in terms of distribution and clustering based on deposition method was attained. From the FTIR measurements, we observed no noticeable change in vibrational frequencies regardless of the deposition method and the thin film thickness. The abnormalities in absorption measurements suggest thickness dependence due to various deposition methods that resulted in oxygen defect-related states that modified the energy band gap. From PL analysis we observed an increase in the emission intensity following the increase in thin film thickness which denotes the change in P3HT conformation as the number of defects increases. Thus, the drop-coating method produced a thicker thin film that revealed outstanding structural and optical properties that are vital for organic photovoltaic (OPV) device functioning. Even though the drop-coating method produced thin films with promising results for OPV devices, it lacks in terms of reproducibility such as controlling thin film thickness which causes extrinsic degradation effects. Thus, the spin-coating method is viable as one can control spin speed to attain the desired thickness for optimum performance of P3HT in OPV devices.

The pursuit of low-power/low-voltage operation in devices has prompted a keen interest in the mesoscale effects within ferroelectric thin films. The downsizing of ferroelectrics can significantly influence performance; for instance, the remanent polarization and coercive field are susceptible to alterations based on thickness. In this study, randomly oriented Bi3.25La0.75Ti3O12 thin films were fabricated on Pt/Ti/SiO2/Si substrates using the sol–gel method, and SEM observations revealed rod-like grains in all thin films. The investigation delved into the correlation between dielectric and ferroelectric properties with thin film thickness. The thin film exhibited an increased remanent polarization and a reduced coercive electric field. Additionally, the ferroelectric domain structure was scrutinized through PFM, and the resistor properties of the BLT4 thin film were studied, which shows the potential of BLT thin films in non-volatile memory and memristor.

To fabricate oxide thin-film transistors (TFTs) with high performance and excellent stability, preparing high-quality semiconductor films in the channel bulk region and minimizing the defect states in the gate dielectric/channel interfaces and back-channel regions is necessary. However, even if an oxide transistor is composed of the same semiconductor film, gate dielectric/channel interface, and back channel, its electrical performance and operational stability are significantly affected by the thickness of the oxide semiconductor. In this study, solution process-based nanometer-scale thickness engineering of InZnO semiconductors was easily performed via repeated solution coating and annealing. The thickness-controlled InZnO films were then applied as channel regions, which were fabricated with almost identical film quality, gate dielectric/channel interface, and back-channel conditions. However, excellent operational stability and electrical performance suitable for oxide TFT backplane was only achieved using an 8 nm thick InZnO film. In contrast, the ultrathin and thicker films exhibited electrical performances that were either very resistive (high positive VTh and low on-current) or excessively conductive (high negative VTh and high off-current). This investigation confirmed that the quality of semiconductor materials, solution process design, and structural parameters, including the dimensions of the channel layer, must be carefully designed to realize high-performance and high-stability oxide TFTs. [ABSTRACT FROM AUTHOR]

Despite theoretical expectations for 2D Weyl semimetals (WSMs), realizing stable 2D topological semimetal states experimentally is currently a great challenge. Here, 2D WSM states achieved by a thickness‐dependent topological phase transition from 3D Dirac semimetal to 2D WSM in molecular‐beam‐epitaxy‐grown Bi0.96Sb0.04 thin films are reported. 2D weak anti‐localization (WAL) and chiral anomaly arise in the Bi0.96Sb0.04 films for thicknesses below ≈10 nm, supporting 2D Weyl semimetallic transport in the films. This is particularly evident from magnetoresistance (MR) measurements which show cusp structures at around B = 0, indicating WAL, and negative MR, typical of chiral anomaly, only for layers with thicknesses below ≈10 nm. The temperature dependencies of the dephasing length for various thicknesses are consistent with those of the MR. Analysis based on second harmonic generation, terahertz emission, Seebeck/Hall effects, Raman scattering, X‐ray diffraction, and X‐ray photoemission demonstrates that the Dirac‐ to Weyl‐semimetal phase transition for films thinner than ≈10 nm is induced by inversion‐symmetry breaking due to the lattice‐mismatch strain between the Bi0.96Sb0.04 film and substrate. The realization of 2D WSMs is particularly significant for applications in high‐speed electronics, spintronics, and quantum computations due to their high mobility, chiral spin, and topologically‐protected quantum qubits. [ABSTRACT FROM AUTHOR]

Transparent conducting films on polymeric substrates are increasingly applied in diverse novel displays and flexible electronics. In this paper, indium tin oxide films on polymeric substrates were deposited by magnetron sputtering using ceramic targets with different doping ratios. These films were characterized by X-ray photoelectron spectroscopy, X-ray diffractometer, atomic force microscopy, spectroscopic ellipsometry, spectrophotometer, sheet resistance meter, and the Hall effect measurement. In terms of transparency and conductivity, the results have shown that the doping ratio played a less important role in determining the optical properties, while the electrical properties were significantly influenced. It was found that, when the thickness was less than 130 nm, these films with the nominal doping ratio of 95:5 (wt. %) demonstrated higher electrical conductivity compared to those with 90:10 (wt. %), which were widely used in industry. Therefore, for the flexible polymeric substrate, the target with a doping ratio of 95:5 (wt. %) could be suitable to achieve high electrical conductivity. [ABSTRACT FROM AUTHOR]

Herein, Sb2S3 thin films are successfully prepared by hydrothermal method using the mixing solution of SbCl3 and sodium citrate as a novel Sb source. The influence of the growth temperature and time, growth solution volume on the properties of Sb2S3 thin films, and the photovoltaic performance of the corresponding solar cells is systematically investigated. The results reveal that the thickness and Sb–O content in Sb2S3 thin films decrease with the increase of the growth temperature and growth solution volume and decrease of the growth time. When the chemical composition and volume of the growth solution are 120 mM SbCl3, 276 mM sodium citrate, 180 mM Na2S2O3, 60 mM thioacetamide, and 28 mL, and the growth temperature and time are 150 °C and 2 h, the thickness and molar ratios of Sb–O:Sb–S/O in Sb2S3 thin films are 295 nm and 0.14 and the corresponding solar cells achieve the power conversion efficiency (PCE) of 7.36%, which is the highest PCE in Sb2S3 solar cells using hydrothermal method. Therefore, the effect of the growth temperature and time, specially the growth solution volume, on the thickness and Sb–O content in Sb2S3 thin films is important for improving the PCE of Sb2S3 solar cells. [ABSTRACT FROM AUTHOR]

As a promising solar absorber material, antimony selenide (Sb2Se3) has gained popularity. However, a lack of knowledge regarding material and device physics has slowed the rapid growth of Sb2Se3-based devices. This study compares the experimental and computational analysis of the photovoltaic performance of Sb2Se3-/CdS-based solar cells. We construct a specific device that may be produced in any lab using the thermal evaporation technique. Experimentally, efficiency is improved from 0.96% to 1.36% by varying the absorber's thickness. Experimental information on Sb2Se3, such as the band gap and thickness, is used in the simulation to check the performance of the device after the optimization of various other parameters, including the series and shunt resistance, and a theoretical maximum efficiency of 4.42% is achieved. Further, the device's efficiency is improved to 11.27% by optimizing the various parameters of the active layer. It thus is demonstrated that the band gap and thickness of active layers strongly affect the overall performance of a photovoltaic device. [ABSTRACT FROM AUTHOR]

In this work, direct passivation of methylammonium tin iodide thin films (MASnI 3) with 4-fluorophenethylammonium iodide (4-FPEAI) eliminating use of toxic solvents and without annealing through sequential physical vapour deposition (SPVD) is reported. The stoichiometry of MASnI 3 was achieved by depositing 100 nm of SnI 2 and 300 nm of MAI, then annealing for 40 min. Subsequently, 4-FPEAI was deposited on top of MASnI 3 with varying thicknesses of 5, 7 and 9 nm. The film's crystallinity was enhanced as FPEAI thickness increased from 5 nm to 7 nm, then reduced to 9 nm, as depicted by XRD. Consequently, the film's crystallite size increased from 35.51, 49.70, and 52.35 nm at 0, 5, and 7 nm FPEAI treatment and decreased to 42.46 nm at 9 nm FPEAI passivation, respectively. Pristine MASnI 3 films showed many pinholes and grain boundaries, while FPEAI modified films exhibited a smooth surface with larger grains and fused grain boundaries (GBs), as revealed by SEM and AFM images. FPEAI filled the voids in the film and acted as a centre for nucleation, enhancing grain growth and lowering surface roughness. The grain sizes obtained were 392.9, 408.9, 444.6 nm, and 308.7 nm for 0, 5, 7 and 9 nm FPEAI treated films. Surface defects and GBs were significantly suppressed in the 4-FPEAI modified film, as revealed by a strong PL emission and reduced defect density. XRD measured after 24 h of nitrogen storage showed that FPEAI modified films displayed better stability where the perovskite peaks were more intense than the bare film, which degraded quickly. FPEAI, being hydrophobic, prevented moisture infiltration into the film through defect passivation, enhancing its stability. Hence, FPEAI passivation improved the optical, morphological and structural properties as well as the stability of MASnI 3 films, which is favourable for application in optoelectronic devices. • Direct surface passivation of MASnI 3 films with 4-FPEAI was done through SPVD. • 4-FPEAI passivation improved the film's morphology, grain size and crystallite size. • The film's RMS roughness was significantly reduced by 4-FPEAI passivation. • The PL intensity of the material was significantly enhanced by 4-FPEAI treatment. • 4-FPEAI hydrophobicity and reduced trap state density enhanced the film's stability. [ABSTRACT FROM AUTHOR]

CTS (Cu 2 SnS 3) can be used in the next generation of thin-film solar cells due to its non-toxicity, affordability, and natural availability. CTS has a direct bandgap, high absorption coefficient, making it an attractive and environmentally friendly choice for fabrication of solar cells. Ultrasonic spray pyrolysis is used to deposit CTS (absorber layer) and ZnS (buffer layer) films and they are characterized by XRD, SEM and UV–Vis spectroscopy. Based on experimental results, numerical simulation has been performed using SCAPS 1D. FTO/CTS/ZnS/Ag is the structure of device, where Ag act as an electrode. In this paper, a study is carried out to investigate the effects of thickness, doping concentrations in CTS and ZnS layer, working temperatures, bandgap variations, and defect densities on these solar cells. At the temperature of 300K, the proposed cell exhibits a power conversion efficiency of 8.25 %, open circuit voltage 0.4252V, short circuit current 24.82 mA/cm2, FF 78.18 % respectively. [ABSTRACT FROM AUTHOR]

The nanometallic Ti and Zr monolayer films with various thicknesses ranging from 600 to 2200 nm were prepared by using magnetron sputtering technique. The microstructure results demonstrated that Ti films transformed from hcp to fcc at t ≤ 600 nm, while Zr films were grown with hcp structure of nanocolumnar grain. Moreover, the grain orientation of hcp Ti films changed from (0002) preferred orientation at t = 1200 nm to random orientation at larger thickness. Subsequently, the hardness and strain rate sensitivity of films were explored by nanoindentation. The Hall-Petch relationship is obviously invalid to explain the film thickness dependent hardening behaviors in Ti and Zr films, and the influence of phase structure, orientation and residual stress on nanoindentation hardness was discussed. It seems that residual stress plays an important role in the determination of hardness in present Ti and Zr films. The negative strain rate sensitivity m appeared during the plastic deformation of fcc Ti films, which is caused by the phase transformation. The underlying deformation mechanism of hcp Ti and Zr films was also discussed. • Phase structure and texture changes with film thickness in Ti films. • The thickness-dependent hardening behaviors are caused by the residual stress. • Partial dislocations emitted from GBs dominant deformation of hcp Ti and Zr films. • The negative m in fcc Ti films may caused by stress driven phase transformation. • The rate dependent deformation mechanisms of Ti and Zr films were discussed. [ABSTRACT FROM AUTHOR]

Cu2ZnSnS4 (CZTS) thin films in 61 nm, 112 nm, 242 nm and 313 nm thickness which have been produced by Pulsed Laser Deposition (PLD) on Soda Lime Glass substrates as a function of the number of laser pulses. As the deposition of ablated material has been augmented with increasing number of laser pulses, it has been noticed that CZTS-ultrathin film's thicknesses and particle sizes have been increased, their crystalline structures have been improved. Larger particles limit the transmission of light and cause thin films to absorb photons. The band gaps of CZTS (61 nm), CZTS (112 nm), CZTS (242 nm) and CZTS (313 nm) thin film which have been determined to be 1.95 eV, 1.90 eV, 1.50 eV and 1.45 eV, respectively. CZTS (61 nm) ultrathin film with the thinnest one among the thin films produced in this work, which is Cu and S poor but Sn and Zn rich. By increasing the thickness of the film, it has been observed that the amount of Cu and S were increased, and the ratio of Sn and Zn were decreased. In addition, it has been systematically investigated that the photocatalytic activity of the ultra-thin CZTS films coated in different thicknesses by PLD method. Among all the photocatalysts, the CZTS (in 242 nm thickness) photocatalyst has exhibited the highest photocatalytic performance, managing to remove 96.1% of methylene blue (MB) in 240 min. Furthermore, the mechanism that performs photocatalysis has been investigated by scavenger experiments, and it was observed that · O 2 - radical ions have an important role in the reaction, while holes have little effect. [ABSTRACT FROM AUTHOR]

In this study, the binding energies of 4-(acetyl amino)-2-aminobenzoic acid molecules that coated on the Indium Tin Oxide (ITO) surface with the self-assembled technique is measured by the XPS method. The thickness of the layer formed on the modified ITO surface is calculated by using XPS technique with an analytical approach. It is reported that the formation of commercially benzoic acid -based self-assembled monolayers (SAMs) is coated surely on ITO that is proved by this technique. According to this approach, the intensity of the substrate-originated photoemission peak from a semi-infinite substrate with a uniform over layer thickness, tXPS(SAM), is obtained from the SAM peak to In3d and Sn3d oxide (ITO) intensity peaks ratio (ISAM/IITO) that the Hill equation allows thin film thickness calculation from XPS data. [ABSTRACT FROM AUTHOR]

Here, niobium-doped monoclinic gallium oxide thin films of different thicknesses were deposited on p-Si (100) and quartz substrates by radio-frequency magnetron sputtering. All films were annealed in argon ambient. The crystal structure and surface morphology of the films were researched using x-ray diffraction and scanning electron microscopy. Then, their crystallite size was evaluated via the Debye–Scherrer formula. The results demonstrated that the films had a good crystal structure and a flat surface when the thickness was around 300 nm. The films' optical properties were also investigated, and the results showed that all of the films' transmittance is above 80% to ultraviolet–visible light whose wavelength is above 350 nm. Meanwhile, the films' optical band gap decreased as their thickness increased. The Urbach energy of all films was calculated by the Urbach rule, and the results indicated that the best crystal quality occurred when the thickness was around 300 nm. The films' electrical characteristics showed that the current was larger when the thickness was around 300 nm and that the contact between the Au electrode and films was Ohmic contact, independent of the film thickness and test conditions. These findings will provide useful information for the practical application of Nb-doped β-Ga2O3 thin films. [ABSTRACT FROM AUTHOR]

In this study, spray pyrolysis was used to produce nanostructured NiO thin films from high purity nickel acetate (Ni(CH3COO)2.3H2O) precursors on pre-heated ultrasonically cleaned soda-lime glass substrates. The metallic constituent concentrations in the films were varied, and the precursors were produced in distilled water at various molarities ranging from 0.1 to 0.4 M. In the study, the field-emission scanning electron microscope (FESEM) results strongly confirmed adherence of the films to the glass substrate at 350 °C. The presence of Ni and O in the samples was confirmed using Rutherford backscattering spectroscopy (RBS), X-ray diffractometry (XRD) and energy dispersive X-ray spectroscopy (EDX). For the 0.1 M NiO thin films, the thickness was approximately 43 nm, and for the 0.2 M, 0.3 M, and 0.4 M films, the thickness was 46 nm, 47 nm, and 49 nm, respectively. The XRD findings were supported by the increased Raman intensity peaks with increased precursor concentration, which confirmed the films' improved crystallinity. For the same number of passes of films deposition, as the molar concentration increases, the films thickness increases. The amount of nickel in NiO thin films increases as the molarity increases, but the amount of oxygen in NiO thin films decreases as the molarity increases. It was discovered that as molarity increases, the optical transmittance decreases and the optical band gap narrows. The qualities of NiO discovered in this study suggest the films’ potentials for usage as window layer and buffer material in thin film solar cells.

FeCo thin films with high saturation magnetization (4 πMs) can be applied in high-frequency electronic devices such as thin film inductors and microwave noise suppressors. However, due to its large magnetocrystalline anisotropy constant and magnetostrictive coefficient of FeCo, the coercivity (Hc) of FeCo films is generally high, which is detrimental to the soft magnetic properties. Meanwhile, the thickness and deposition temperature have significant effects on the coercivity and saturation magnetization of FeCo films. In this paper, FeCo thin films with different thicknesses were prepared by magnetron sputtering at different temperatures. The effects of thickness and deposition temperature on the microstructure and magnetic properties of FeCo thin films were systematically studied. When the film thickness increases from 50 nm to 800 nm, the coercivity would decrease from 309 Oe to 160 Oe. However, the saturation magnetization decreases from 22.1 kG to 15.3 kG. After that, we try to further increase the deposition temperature from room temperature (RT) to 475 °C. It is intriguing to find that the coercivity greatly decreased from 160 Oe to 3 Oe (decreased by 98%), and the saturation magnetization increased from 15.3 kG to 23.5 kG (increased by 53%) for the film with thickness of 800 nm. For the film with thickness of 50 nm, the coercivity also greatly decreased from 309 Oe to 10 Oe (decreased by 96%), but the saturation magnetization did not change significantly. It is contributed to the increase of deposition temperature, which will lead to the increase of grain size and the decrease of the number of grain boundaries. And the coercivity decreases as the number of grain boundaries decreases. Meanwhile, for the thicker films, when increasing the deposition temperature the thermal stress increases, which changes the appearance of (200) texture, and the saturation magnetization increases. Whereas, it has a negligible effect on the orientation of thin films with small thickness (50 nm). This indicates that high-temperature deposition is beneficial to the soft magnetic properties of FeCo thin films, particularly for the films with larger thickness. This FeCo thin film with high saturation magnetization and low coercivity could be an ideal candidate for high-frequency electronic devices. [ABSTRACT FROM AUTHOR]

• An improved fitting method was developed to accurately measure ultrathin sample. • Accurately measured SAM have a mean thickness of 0.89 nm and a RI of 1.387. • Fabrication of ultra-thin SAM films using semiconductor fabrication techniques. • Non-contact characterization of thickness and optical property of ultrathin sample. A differential interference contrast (DIC) system was introduced to guide non-destructive ellipsometer metrology for characterizing ultrathin-film. Patterned self-assembled monolayer was fabricated as ultrathin-film samples. Furthermore, an improved fitting method was developed to describe the samples. The ellipsometer analysis revealed a mean thickness of 0.89 nm and a refractive index of 1.387 for the samples, consistent with Atomic Force Microscopy results and previous reports. These results validate well performance ellipsometers combination with DIC systems as preferred non-destructive characterization tools for determining the ultrathin film. Moreover, the potential capability of the DIC-guided ellipsometry technique was verified in the field of patterned ultrathin film measurements. [ABSTRACT FROM AUTHOR]

In this work, Cd 1-x Zn x S nanocrystalline thin films have been synthesized over a glass substrate by a simple and cost-effective Chemical Bath Deposition (CBD) technique at various deposition time keeping other deposition parameters constant. The structural, morphological, and optical properties are studied by incorporating a range of characterization techniques, including X-ray diffraction (XRD), Field Emission Scanning Electron Microscopes (FESEM), Energy Dispersive X-rays (EDX), and UV–Visible spectrophotometers (UV–Vis). The films have been deposited at five different deposition time in the range from 30 mins to 150 mins to record the changes which address in depth the structural, morphological and optical properties. Empirical fitting equations have also been developed to obtain a more quantitative analysis of the effect of deposition time. The results obtained in this work are compared with some recent reported works for performance analysis of the buffer layer. The proposed buffer layer deposited at 30 mins not only attains all the desirable qualities required for maximum extraction of solar energy but also a low-cost and environment friendly option, making it a potential candidate for solar cell and optoelectronic applications. [Display omitted] • The Cd 1-x Zn x S thin films has been synthesized by using Chemical Bath Deposition (CBD) method. • XRD analysis reveals the nanocrystalline nature and hexagonal phase structure of deposited films. • FESEM images display smooth, crack free and dense morphology of deposited films. • The deposited films shows wide and tunable band gap from 2.4 to 2.8 eV. • A simple and controllable method has been introduced with adjustable crystallite size, thickness and band gap. [ABSTRACT FROM AUTHOR]

This study presents a two-step synthesis approach utilizing the hydrothermal method and drop casting for the fabrication of FeVO 4 (FVO) nanopebble thin films onto FTO-coated glass substrates, employing sacrificial basic FeOOH (FOH) nanostructured thin films. X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of FVO nanopebble thin films. Morphological and elemental analyses revealed that the thickness and grain size of the FVO nanopebbles increased, reaching maximum values depending on the parent FOH nanostructures. Additionally, the optimized FVO nanopebbles exhibited a high content of oxygen vacancies. Furthermore, a gradual increase in grain size and film thickness observed through the phenomenon of red-shifting in the optical band gap. The well-optimized FVO photoanode delivers the highest photocurrent density of 0.3 mA cm−2 at an applied bias of 1.6 V (vs. RHE) under standard illumination, demonstrating exceptional stability under these conditions. Moreover, the photoanode exhibited outstanding injection efficiency of 96.7 % compared to separation efficiency, as evidenced by photoelectrochemical impedance spectroscopy (PEIS) studies. Furthermore, the optimized photoelectrode exhibited a hydrogen evolution rate of 11.96 μmol h−1cm−2 with a faradaic efficiency of 98.73 % after one hour. Overall, the synthesized FVO nanopebble thin films shows promising potential for efficient photoelectrochemical water splitting applications. [Display omitted] • Two-step synthesis involving hydrothermal and drop casing for the fabrication of FeVO 4 nanopebble thin film structure. • Morphological analysis shows the increased thickness and grain size for the optimum of FeVO 4 nanopebble thin film. • High oxygen vacancies were identified for the best FeVO 4 nanopebble thin film. • Exceptional stability along with outstanding injection efficiency were registered. • High rate of hydrogen evolution with remarkable Faradaic efficiency have been recorded. [ABSTRACT FROM AUTHOR]

Ni thin films with different thicknesses were grown on a GaAs substrate using the magnetron sputtering technique followed by in situ X-ray diffraction (XRD) annealing in order to study the solid-state reaction between Ni and GaAs substrate. The thickness dependence on the formation of the intermetallic phases was investigated using in situ and ex situ XRD, pole figures, and atom probe tomography (APT). The results indicate that the 20 nm-thick Ni film exhibits an epitaxial relation with the GaAs substrate, which is (001) Ni//(001) GaAs and [111] Ni//[110] GaAs after deposition. Increasing the film's thickness results in a change of the Ni film's texture. This difference has an impact on the formation temperature of Ni3GaAs. This temperature decreases simultaneously with the thickness increase. This is due to the coherent/incoherent nature of the initial Ni/GaAs interface. The Ni3GaAs phase decomposes into the binary and ternary compounds xNiAs and Ni3−xGaAs1−x at about 400 °C. Similarly to Ni3GaAs, the decomposition temperature of the second phase also depends on the initial thickness of the Ni layer. [ABSTRACT FROM AUTHOR]

Germanium monoselenide (GeSe) has been considered to be a promising photovoltaic absorber material due to its excellent photoelectric properties such as suitable band gap, high absorption coefficient and high carrier mobility. In this paper, the thin film solar cells with the proposed structure of metal grid/AZO/i-ZnO/CdS/GeSe/Mo/glass were simulated. The solar cells output performance parameters were investigated and evaluated in response to changes in materials properties of functional layers (such as thickness, carrier concentration and bulk defect density). After optimizing the thickness and doping concentration of CdS buffer layer and GeSe absorber layer, respectively, the solar cells show a conversion efficiency of 27.59%. Finally, the effect of bulk defect density in the absorber layer on the device performance was simulated. These results show that GeSe based thin film solar cells have the potential to become a high efficiency photovoltaic device. [ABSTRACT FROM AUTHOR]

Cobalt-Molybdenum-Tungsten (CoMoW) alloy thin films were prepared through an induced electroplating route from a citrate bath on the surface of the copper electrode at the controlled value of pH 8. The CoMoW thin films have been prepared by varying the Mo concentrations like 0.1, 0.2, 0.3 and 0.4 M at a deposition time of 30 minutes over a plating current potential of 40 mA / cm2. The electrodeposited CoMoW coatings have been investigated with the help of Field Emission Scanning Electron Microscopy (FESEM), powder crystal X-ray diffraction (XRD), Electrochemical studies (impedance and polarization) and Vibrating Sample Magnetometer (VSM) to reveal its respective microstructure-based information, mechanical and soft magnetic nature of the synthesized CoMoW thin layers. The CoMoW thin films of an HCP crystal structure have been attained. The induced electroplated condition such as Mo concentration has a significant impact on the crystal structure system, surface morphology, and soft magnetic performances. The crystalline size of the CoMoW thin layers has varied from 22.66 nm to 42.87 nm. The synthesized CoMoW thin layers were smooth, without cracks and had uniform morphology. All the electroplated CoMoW films have the highest Co content along with low Mo content (Co content gradually decreased while increasing the Mo content in the deposits) and thickness varied from 10 to 20 µm. Through the electrochemical investigation studies, it is concluded that the corrosion rate of CoMoW thin films was slightly increased by increasing the Mo content and the corrosion resistance varied from 80.2 KO to 92.7 KO. The CoMoW thin alloy films with higher Co content exhibited a lower coercivity value of 3.69 Oe and the saturation magnetization of 49.049 emu/cm². [ABSTRACT FROM AUTHOR]

Indirect bandgap in Si‐based semiconductor limits its widespread usage as the main component for effective sunlight harvesting and led to the development of new silicon structures with small direct bandgaps and desired optical properties. Herein, the synthesis of quasi‐direct bandgap silicon nanoparticles (SiNP) by a one‐pot hydrothermal process and their application as an active layer of photodetectors are reported. The result shows that these photodetectors are operable over a long range of wavelengths and can respond in just 0.4 ms. Systematic characterizations of multiple devices led to determining the critical thickness of the silicon nanoparticles (SiNPs) active layer in photodetectors for its optimum response. The reliability, repeatability, and range of operation of an optimized device have been evaluated. This work suggests the usability of SiNP for the development of photodetectors and the significance of the thickness of the SiNP active layer in the further fabrication of optoelectronic devices. [ABSTRACT FROM AUTHOR]

Cuprous oxide (Cu2O) is a p-type metal oxide semiconducting material with potential in photovoltaic and photocatalysis applications due to its excellent absorption capacity in visible region and tunable energy gap. Experimental synth- esis and energy gap characterization of thin film cuprous oxide semiconductor with desired dopants and varying experimental conditions for enhanced photocatalytic as well as photovoltaic activities are laborious and consume appreciable precious resources. This work hybridizes particle swarm optimization method with support vector regression algorithm for computing energy gap of thin film cuprous oxide semiconductor using the thickness of thin film and distorted lattice parameter as descriptors. The predictions of swarm-based support vector regression (S-SVR) model are compared with estimates of stepwise regression (SR) model while S-SVR shows superior performance of 39.47 %, 36.20 % and 114.41 % on testing data samples over SR model using root mean square error (RMSE), mean absolute error (MAE) and correlation coefficient (CC), respectively. The developed S-SVR model is characterized with 0.9559 CC, 0.0586 MAE and 0.028 RMSE on the basis of training samples. The developed S-SVR and SR models were further validated using external data samples while the developed S-SVR demonstrates excellent agreement with the measured values. The convincing precision demonstrated by S-SVR model would be of indispensable significance in determining energy gap of cuprous oxide semi- conductor (for photocatalytic applications in pollutant removal, solar cell, gas sen- sors and thin film transistors) with appreciable quickness and reduced cost coupled with experimental difficulty circumvention. [ABSTRACT FROM AUTHOR]

• Sb 2 Se 3 comprises only two elements, which reduces the possibility of defect formation as with CIGS, CZTS thin film solar cells. • Using SCAPS, the impact of temperature and thickness of absorber and buffer layer on the electrical properties of Sb 2 Se 3 solar cells in terms of I-V, C-V measurements are simulated. • The simulated efficiency for Sb 2 Se 3 with a back-contact metal's work function of 5.1 eV at 200 K was observed to be 27.84%. • The highest efficiency for Sb 2 Se 3 solar cells is obtained with a radiative recombination coefficient value lower than 10−8 cm3/s. Antimony selenide, Sb 2 Se 3 , is a viable candidate for future generation solar cells because it is made from non-toxic, earth-abundant, and low-cost materials. Solar cells based on Sb 2 Se 3 material have got worldwide attention because of their excellent power conversion efficiency. The simulation was carried out using the numerical simulation software SCAPS-1D (solar cell and capacitance simulator). The impact of temperature and thickness of absorber and buffer layer on the electrical properties of Sb 2 Se 3 solar cells in terms of I-V, C-V measurements are reported. The simulated efficiency for Sb 2 Se 3 with a back-contact metal work function of 5.1 eV at 200 K was observed to be 27.84%. As the temperature and thickness of the absorber layer rise from 200 to 350 K and 0.8–3.2 µm, respectively, the efficiency falls from 27.84% to 12.74%. The highest efficiency for Sb 2 Se 3 solar cells is obtained with a radiative recombination coefficient value lower than 10−8 cm3/s. This work can help to improve the performance of Sb 2 Se 3 based solar cells. [ABSTRACT FROM AUTHOR]

Polymer thin films with thickness below 100 nm are a fascinating class of 2D materials with commercial and research applications in many branches ranging from coatings to photoresists and insulating materials, to mention just a few uses. Biopolymers have extended the scope of polymer thin films with unique materials such as cellulose, cellulose nanocrystals, cellulose nanofibrils with tunable water uptake, crystallinity and optical properties. The key information needed in thin biopolymer film use and research is film thickness. It is often challenging to determine precisely and hence several techniques and their combinations are used. Additional challenges with hydrophilic biopolymers such as cellulose are the presence of humidity and the soft and often heterogenous structure of the films. This minireview summarizes currently used methods and techniques for biopolymer thin film thickness analysis and outlines challenges for accurate and reproducible characterization. Cellulose is chosen as the representative biopolymer.

• It is proved that there is a wavelength threshold in the reflectivity spectrum. • Wide spectral trapping is realized by adjusting the wavelength threshold. • Reflectivity and parasitic absorption are managed by adjusting PEDOT:PSS film. • The quasi-Fermi level at PEDOT:PSS/Si interface can be adjusted. • Optical and electrical co-optimization is realized for excellent efficiency. Ultrathin PEDOT:PSS film induces inversion layer within Si to achieve carrier separation, but it as the window-layer directly affects the light absorption. Herein, we show that management of reflectivity and parasitic absorption by adjusting PEDOT:PSS film thickness improves light absorption of active layer. According to the equivalent optical admittance theory and the finite element method, it is found that the reflectivity spectrum is divided into periodic and aperiodic regions by a certain wavelength threshold. When the threshold is close to 300 nm, the smaller reflection and parasitic absorption can be achieved. Meanwhile, with the increase of PEDOT:PSS film thickness, the quasi-Fermi level bending gradually weakens, and the hole concentration gradually keeps stable. This improves the carrier separation efficiency to reduce the carrier recombination, which ensures the improvement of solar cell performance. Finally, the power conversion efficiency (PCE) of 12.35% is obtained by applying the rule obtained from the simulation to the experiment, which is 30% higher than that of the unoptimized PEDOT:PSS/Si hybrid solar cell. [ABSTRACT FROM AUTHOR]

A seed-layer-assisted electrochemical deposition method has been developed to create high-quality ZnMgO thin films on ZnO seed-layer-coated fluorine-doped indium oxide (FTO) glass substrates. The effects of seed layers thickness on the electrochemical, morphological, structural, optical, and electrical properties of the electrodeposited films were investigated. The electrochemical characterization by Mott–Schottky and impedance spectroscopy showed a significant improvement in the charges carrier concentration and interfacial charge transfer resistance for ZnO seed-layer-assisted ZnMgO thin films. X-ray diffraction analysis indicated that the prepared samples were of polycrystalline nature with a highly wurtzite ZnO (002)-oriented crystallites. Furthermore, the surface texturing and smoothness of ZnMgO/ZnO/FTO thin films were greatly improved with the increase in the ZnO seed layers thickness. The optical measurements showed the enhancement of the optical transmittance for ZnMgO layers deposited with thick seeds. Current–voltage characteristics of Au/ZnMgO/ZnO/FTO samples showed high electrical performance by the inclusion of seed layers approach. [ABSTRACT FROM AUTHOR]

Magnesium oxide (MgO) thin films with various thicknesses were successfully developed on glass substrates by sol–gel dip-coating technique. We have investigated the influence of the thickness (157, 352, and 915 nm), on the structural, optical, and morphological properties. X-ray diffraction study revealed that the deposited films were polycrystalline in nature with face-centered cubic structure along (200) and (220) directions. The transmittance was found to be decreased as the film thickness increased. In parallel, the optical band gap was found to be increased from 3.88 to 3.98 eV. The microstructure was found to be converted from inhomogeneous grains distribution with some voids in the surface to islands shapes distributed on homogeneous surface with increasing of the thickness. FTIR and EDX analysis confirmed the presence of Mg and oxygen elements. Also, the films were highly stoichiometric. [ABSTRACT FROM AUTHOR]