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GdMnO3 (GMO) thin films were sputtered using an RF Magnetron unit on Quartz substrates. Films post-annealed for 12 h at 750 ℃ and 850 ℃ confirm the orthorhombic structure with pbnm symmetry. The increase in temperature of the films increases their crystallinity and grain size. Raman study substantiates the results of XRD. Annealing at higher temperatures shows a broadening in Raman peaks along with a right shift in the active modes. XPS anlaysis revelas the presense of Mn with Mn3+ and Mn4+ oxidation state. The AFM topography images show increased values in average roughness, root mean square roughness, Kurtosis, skewness and Shannon entropy as a function of rising temperature values. The second-order transition from the incommensurate antiferromagnetic phase to the canted A-type commensurate antiferromagnetic phase is observed. The magnetization value is found to be higher for the film annealed at 850 ℃, whereas the film annealed at 750 ℃ exhibits spin glass behaviour. [ABSTRACT FROM AUTHOR]

The incorporation of nanostructures such as silicon nanocrystals into the oxide of an MOS structure has attracted significant interest in improving the performance of MOS-based devices. However, integrating crystalline silicon quantum wells into this structure remains a challenge due to the difficulties associated with growing a crystalline Si film on an amorphous oxide. This study presents the fabrication and electrical characterization of a quantum well formed by the thermal oxidation of an ultrathin silicon-on-insulator (UT-SOI) film. Structural analysis by electronic transmission reveals the formation of a monocrystalline quantum well with a homogeneous thickness and a perfectly flat surface, free from any crystalline defect. The electrical characterizations, carried out using capacitance–voltage (C–V) and current–voltage (I–V) measurements, confirm the success of the integration of the quantum well into the MOS structure. In addition, a systematic study of the dielectric properties details the evolution in bias voltage and in frequency of the main dielectric parameters of the structure such as the dielectric constant (ε*), the electrical loss (Tan δ), and the electrical modulus (M*). The results obtained demonstrate normal operation of the new structure, paving the way for efficient integration of this type of nanostructures in MOS-based photodetectors and solar cells. [ABSTRACT FROM AUTHOR]

In this work, we investigate the optical properties of silicon nitride doped with Cerium: Ce: SiN0.38 and Ce: SiN0.55 films produced by thermal evaporation deposition. Silicon nanocrystals (Si-Ncs) incorporated silicon rich-silicon nitride films (SiNx<1.33) were developed on Silicon substrate using Plasma Enhanced Chemical vapor technique (PECVD). The GIXRD and Raman analysis show the formation of Si-Ncs in two layers studied, SiN0.38 and SiN0.55 with the average size of 6 and 3 nm, respectively. The morphology, structure and chemical properties of annealed Ce doped SiNx were investigated by energy-dispersive X-ray spectroscopy (EDS), scanning- electron- microscopy (SEM) and elemental mapping, demonstrating that Ce was integrated into the SiNx layer. Si-Ncs size's effect on the photoluminescence (PL) response after doping by evaporation is studied. Layers with the small Si-Ncs exhibited a strong increase in the PL intensity in the blue region. Energy transfer between the small Si-Ncs and the Ce is the probable source of enhanced PL emission. The layers with large Si-Ncs did not show any indication of a Ce ion interaction. Highlight: Substoichiometric SiNx˂1.33 matrix was discovered by an Industrial LF-PECVD reactor. Luminescent Si-Ncs of various size have been synthesized in the SiNx matrix. A simple and repeatable technique is utilized to generate and incorporate rare earth ions (Cerium) into the silicon nitride matrix. Energy transfer from Si nanocrystals to Ce occurs for small Si-Ncs. This process can be introduced into the cell production line easily with low-cost. [ABSTRACT FROM AUTHOR]

In this work, CdS thin films were prepared on glass substrates using the chemical bath deposition method. The samples were used as a gas sensor for NO2 in the range of 5–50 ppm and H2S in the range of 10–50 ppm. The sensor was operated at room temperature and activated by UV LED illumination of 395 nm. The morphology, optical, and electrical properties of this nanostructure were examined using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, spectroscopic ellipsometry, UV–Vis spectroscopy and 3D optical profilometry. The films are highly sensitive to NO2 and H2S with a response of 75 and 52% at 50 ppm respectively. Furthermore, they showed good long duration stability and short response/recovery times. The sensor response to NO2 gas increases linearly with increasing gas concentration, while for H2S gas the rate of increase of the sensor response becomes greater from 20 ppm. The results obtained suggest that the developed sensor may have great application potential to detect toxic gases such as H2S and NO2 at room temperature. [ABSTRACT FROM AUTHOR]

RF reactive sputtering was used to deposit copper tantalum nitride (CuTaN2) films from a Cu/Ta target in an environment containing a mixture of argon and nitrogen at two different substrate temperatures: room temperature and 200 °C. The films were studied by SEM, EDS, XRD, Raman spectroscopy, spectrophotometry, and resistivity measurements. The deposition conditions significantly impacted the morphology of the films, which varied from smooth, void-free films at high nitrogen concentrations and at room temperature substrates to cauliflower-like grains with voids at low nitrogen contents and elevated substrate temperatures. Despite the target's 1:1 Cu: Ta ratio, the stoichiometric analysis showed a lower Ta content in the deposited film. The films produced on silicon substrates were polycrystalline, whereas those deposited on glass substrates were amorphous. The band gap (0.9 eV to 1.55 eV) and film resistivity (20 kΩ-cm to 76 kΩ-cm) are strongly affected by the nitrogen fraction in the sputtering gas. Increasing the nitrogen percentage in semiconductor films results in smoother films with larger bandgaps (approximately 1.5 eV), higher resistivity, and compositions closest to those of stoichiometric CuTaN2. [ABSTRACT FROM AUTHOR]

Magnetoelectric composite materials, which exhibit both ferroelectric and ferromagnetic properties simultaneously, have attracted considerable interest for their potential in various applications such as microelectronics, memory devices, and spintronics. In this study, we investigated the synthesis, structural, morphological, electrical, and magnetic properties of multiferroic CoFe2O4/0.65BiFeO3-0.35PbTiO3 (CFO/65BF-35PT) composite thin films. These films were prepared using a high ferroelectric, morphotropic phase boundary (MPB) composition, 65BF-35PT, combined with a high magnetostrictive compound, CFO. Multilayered CFO/65BF-35PT composite films were spin-coated onto fluorine-doped tin oxide (FTO)/glass substrates using the sol-gel method, with variation in the solution molarity to achieve different layer thicknesses. Structural analysis revealed a perovskite phase for 65BF-35PT and a spinal structure for CFO, with the presence of rhombohedral and tetragonal polymorphs confirming MPB composition. Scanning electron microscope images demonstrated uniform growth of 1 μm thick composite films. Ferroelectric hysteresis loops exhibited considerable leakage current at room temperature, increasing with higher CFO content, while current versus voltage plots revealed ohmic conduction at low applied fields and space charge limited current (SCLC) conduction at high fields in all composite films. The crossover field between ohmic and SCLC conduction decreased with increasing CFO content. Moreover, room-temperature magnetic hysteresis loops showed a decrease in saturation and coercive field with increasing CFO concentration, and the temperature-dependent magnetization response indicated a monotonic decrease, with magnetization vanishing around 800 K, confirming the magnetic order of CFO. Our findings demonstrate that stable ferroelectric and ferromagnetic phases can be achieved at low temperatures by depositing composite films containing CFO/MPB on a low-cost FTO substrate. [ABSTRACT FROM AUTHOR]

The composite metal oxide thin films, (1–x)(SnO2)-(x)(Pr2O3) (where x = 0.0, 0.25, 0.50, 0.75, 1.0 at.%), were coated using the laboratory spray pyrolysis method. Their structural, vibrational, morphological, compositional and optical properties were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), ultraviolet–visible near-infrared spectroscopy (UV–Vis. NIR) and photoluminescence spectroscopy (PL). XRD studies confirmed that the deposited (1–x)(SnO2)-(x)(Pr2O3) composite thin film adhered to the tetragonal phase for x = 0.0, the hexagonal phase for x = 1.0, and a combined phase for x = 0.25, 0.50, and 0.75 at.%. Additionally, the crystallite size decreased with the addition of rare earth composite. FTIR spectra revealed the basic vibrational modes of Sn–O and Pr–O. XPS analysis disclosed the Sn, Pr, and O chemical valence states, as well as oxygen vacancies on the surface. FESEM analysis showed that the morphology of composite thin films was significantly altered by Pr2O3 content. EDX study revealed the presence of Sn, Pr, and O elements. Root mean square (RMS) roughness values identified through AFM analysis could contribute to enhancing photocatalytic performance. PL analysis revealed the recombination of photo-generated charge carriers, surface, and lattice oxygen defects. The calculated edge potential of the conduction and valence bands in SnO2, Pr2O3, and their composites revealed a defect energy level, which is efficient for visible photocatalytic dye degradation capabilities. A high visible light photocatalytic efficiency of 93%, against methylene blue dye, of the composite thin film (0.50SnO2 − 0.50Pr2O3) is primarily attributed to its extended light absorption capability, appropriate band edge alignment between SnO2 and Pr2O3, minimal electron–hole pair recombination, and efficient charge transfer. [ABSTRACT FROM AUTHOR]

In this work, we investigated the effect of substrate on the structural, morphological, and magnetic properties of electrodeposited CoNi thin films from a chloride bath. Three samples of CoNi films were deposited at room temperature onto different substrates: FTO, ITO, and Cu. Electrochemical studies were performed using cyclic voltammetry experiments. Energy-dispersive X-ray spectroscopy (EDX) showed that all the samples had a cobalt content of more than 80%. X-ray diffraction (XRD) spectra revealed that the films deposited on Cu had a face-centered cubic (FCC) phase, while those deposited on ITO and FTO had a mixture of hexagonal close-packed (HCP) and FCC phases. The lattice parameter (a) and crystallite size (D) were strongly dependent on the substrate. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to observe the morphology of the films. All the samples had a granular morphology with spherical grains, but the roughness and surface distribution varied with the substrate. The magnetic properties of the films, such as coercivity (Hc) and squareness (S), were investigated using a vibrating sample magnetometer (VSM). The results showed that Hc and S were both affected by the substrate and the film composition. Overall, our results showed that the substrate had a significant effect on the structural, morphological, and magnetic properties of electrodeposited CoNi thin films. These findings could be used to design and optimize CoNi thin films for specific applications. [ABSTRACT FROM AUTHOR]

Defects and oxygen vacancies always play an important role in the properties of ferroelectric films. Here, we prepared (1 − x)BiFeO3–xSrCoO2.5 films by the sol–gel method, and introduced SrCoO2.5 into BiFeO3 to form an unequal solid solution, thereby generating defective dipoles in the film to regulate the ferroelectric photovoltaic effect. It is shown that the appearance of defective dipoles intensifies the asymmetry of positive and negative charges in the lattice and improves the ferroelectric properties of the films, with remanent polarization of 69.2 μC/cm2 in the 0.98BiFeO3–0.02SrCoO2.5 film. Moreover, the addition of SrCoO2.5 also weakens the orbital hybridization of B–O bonds, reducing the bandgap of the film to 2.42 eV. The open circuit voltage of 10 mV and short circuit current of 0.52 μA/cm2 are obtained in the 0.98BiFeO3–0.02SrCoO2.5 film. This work provides a new strategy for regulating the ferroelectric photovoltaic effect. [ABSTRACT FROM AUTHOR]

Vanadium oxide thin film has been grown on a glass substrate utilizing the spray pyrolysis technique. In the present work, by using Vanadyl acetylacetonate (C10H14O5V) as a salt source, we have succeeded, for the first time, to the best of our knowledge in the formation of VO 2 instead of the commonly produced V 2 O 5 . The influence of salt concentration and substrate temperature is investigated. Structural, morphological, optical and electrical properties of the synthesized VO 2 thin films were characterized by several techniques such as ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmittance and electrical resistivity. The XRD analysis revealed that the effect of substrate temperature is more significant at low salt concentrations. At high salt concentrations, the crystallite size varies slightly with increasing the substrate temperature. The Raman spectroscopy comforts the presence of a small amount of the V 2 O 5 especially at higher salt concentration. The whole synthesized films exhibit a continuous pinholes-free and dense structure. The influence of the substrate temperature on the film morphology depends on the used salt molarity. Increasing the substrate temperature causes the formation of needle-like features, at a low molarity of 0.05M, while, at a high molarity of 0.1M, spherically shaped grains are formed. A similar trend of the influence of the substrate temperature on the optical properties of the film is observed. At low molarity, increasing the substrate temperature causes an increase in the vanadium thin film band gap. On the contrary, at higher molarity, the reverse behavior is observed i.e. the band gap reduction. The semiconductor metal transition has been observed in the prepared VO 2 films. However, this transition is not too drastic due, on one hand, to the presence of disorder in the film network and on the other hand to the presence of vanadium vacancy defects. [ABSTRACT FROM AUTHOR]

This work aims on developing plasmonic bismuth (Bi) thin films for ultra-sensitive detection of L-tyrosine (Tyr) using label-free Surface Enhanced Raman Spectroscopy (SERS) technique. Tyr is a crucial precursor in the formation of several neurotransmitters, melanin, and thyroid hormones. Sensing the qualitative and quantitative imbalances in Tyr opens up the possibility of diagnosing a variety of autoimmune, neurodegenerative, and physiological illnesses. Bi thin films were fabricated through DC magnetron sputtering employing both in-situ deposition and ex-situ vacuum annealing processes. Varied annealing temperatures of 100 °C and 200 °C were used in each case. Among all, the ex-situ films at 200 °C exhibited enhanced microstructural, morphological, and optical characteristics. This film showed an optimum surface morphology aiding in intense Localized Surface Plasmon Resonance (LSPR) absorption. The HRSTEM results observed are supported by Raman modes and GI-XRD pattern. A preferential orientation change is observed in the tailored Bi film. Multiple SPRs arising from interband transitions and XPS etching studies confirm the metallic nature of Bi films. FESEM with EDS demonstrates film homogeneity and compositional purity. All the Bi films were tested for a preliminary SERS limit of detection (LoD) study using Rhodamine 6G (RH6G), for selecting a better substrate, supported by the hydrophobicity and Raman mapping studies done. The optimized SERS platform exhibited an unprecedented sensitivity, reaching upto 1 pM level LoD for Tyr with an ultra-sensitive SERS Enhancement Factor (EF) of 1.69 × 1012. The detection of Tyr suggests the potential of Bi thin films as a promising alternative for ultra-sensitive SERS biosensing platforms. [ABSTRACT FROM AUTHOR]

Charge transport studies on pulsed laser deposition grown Y0.95Ca0.05MnO3 (YCMO) thin film on (100) single crystalline Nb:SrTiO3 (SNTO) substrate. X-ray diffraction analysis reveals the single phase nature of YCMO manganite film having lattice mismatch between YCMO thin layer and SNTO substrate. Surface morphology, studied using atomic force microscopy, indicates the presence of island like grain growth with narrow size distribution. Transport properties have been studied by performing temperature dependent resistivity under different applied voltages across the YCMO/SNTO interface to understand the charge conduction across the same interface. The observed electric field-induced modifications in interface resistance across the YCMO/SNTO lattice have been discussed in the contexts of barrier between YCMO and SNTO, oxygen vacancies, structural disorder and structurally strained region at the film–substrate interface. Electrical resistance has been theoretically fitted using various models and mechanisms to better understand the charge conduction mechanisms in the semiconducting region for the YCMO/SNTO interface. [ABSTRACT FROM AUTHOR]

PbS QDs and PbS QDs decorated with reduced graphene (rGO) are prepared by hot-injection method using PbO and hexamethyldisilathiane (HMDS) as Pb and S sources, respectively. PbS QDs and PbS QDs:rGO are used as an addition to poly(3-hexylthiophene-2,5-diyl):phenyl-C61-butyric acid methyl ester (P3HT:PC61BM) composite. The effect of their addition on the morphological, topographical and optical properties of spin-coated P3HT:PC61BM thin films are investigated. These additions tune the films to be more homogenous and more flatness as investigated in terms of field scanning electron microscope. The topographical properties of the films are explored by atomic force microscope. The results show decreasing in the grain size and the surface roughness in P3HT:PbSQDs:PC61BM film compared to other composites films. The optical properties of the films are studied over the spectral range 200–2500 nm. On one hand, the absorption coefficient of different films is computed and the optical band gap of the films is found to decrease after addition of PbS QDs and PbS QDs:rGO. On the other hand, the refractive index of the films is explained according to the single-oscillator model to get the dispersion parameters. In addition, the lattice dielectric constant and the ratio of the free-carriers concertation to their effective mass are evaluated. [ABSTRACT FROM AUTHOR]

This study employs zinc acetate as the precursor for synthesizing pure zinc oxide thin films through the sol–gel process. Comprehensive characterization and analysis were conducted using X-ray diffraction, field-emission scanning electron microscopy, ultraviolet–visible-infrared spectrophotometry, ellipsometry, and photoluminescence. The X-ray diffraction study confirms the hexagonal wurtzite polycrystalline structure of zinc oxide. Increasing the zinc precursor concentration resulted in a decrease in the observed intensity of diffraction lines, as revealed by XRD studies. Microstructural parameters such as crystallite size and micro-strain were determined using the Scherrer equation and the Williamson–Hall method. The Williamson–Hall method indicated an increase in crystallite size values from 28.3 to 36.9 nm, while micro-strain values decreased from 1.192 × 10−3 to 1.12 × 10−3 with an increase in zinc acetate concentration from 0.1 M to 0.5 M. Scanning electron microscopy images displayed connected microstructures with wrinkle network architectures influenced by the concentration of zinc acetate, consistent with the texture coefficient results. Optical characteristics were investigated in the 300–2500 nm range through transmission measurements and subsequent photoluminescence measurements. The optical band-gap energy was found to decrease from 3.33 to 3.21 eV and the band tail width (Urbach energy) decreased from 0.344 to 0.105 eV with an increase in zinc concentration. [ABSTRACT FROM AUTHOR]

By employing a nebulizer spray pyrolysis approach, thin films of CdS, Al, La, and Al–La co-doped CdS thin films have been effectively formed on glass substrates, and their physical characteristics have been examined. The structural investigations confirmed the hexagonal structure of CdS with a preference for orientation along the (1 0 1) plane. The maximum crystallite size was observed for the Al–La co-doped CdS film compared to other prepared thin films. The granular structure was distributed uniformly for all the films according to FESEM data. To determine the optical characteristics with Al, La, and Al–La co-doping, transmittance was examined and found that the Al–La co-doped CdS thin film exhibit lower transparency due to enhanced light scattering. The energy band-gap value slightly decreased from 1.58 to 1.56 eV for the undoped and co-doped CdS films. The doping causes an enhancement of the emission peaks for doped and co-doped CdS films at ambient temperature, and the gas-sensing performance of both pristine and doped CdS thin films was examined for ammonia (NH3) gas. Doped CdS films were shown to be significantly more sensitive and a higher gas response (1390) to NH3 than pristine CdS thin film. The present study also showed that the co-doping of Al and La with CdS exhibited a faster response and recovery time of (42/21 s) during NH3 gas detection. [ABSTRACT FROM AUTHOR]

Incorporating substitutional elements from groups I, II and IV is an important approach to improve the quality of kesterite thin films. Among the elements, Ag and Ge are most effective in promoting the performance of Cu2ZnSn(S,Se)4 solar cells. Although several theoretical and experimental studies have been conducted on the Ag/Ge-alloyed kesterite, there are significant differences in the reported morphological characteristics, photovoltaic performance and even the optimal Ag/Ge substitution ratio due to different preparation processes utilized, which leads to difficulties in comparing the Ag-incorporated and Ge-incorporated kesterite solar cells. Currently, there is little literature on the comparative study concerned. Herein, we fabricated Ag-alloyed and Ge-alloyed kesterite solar cells based on the same solution method and process conditions, and laterally compared the effects of Ag substitution and Ge substitution on the phase compositions, morphologies, optical bandgaps, minority carrier lifetime and device performance of kesterite Cu2ZnSn(S,Se)4 thin films. [ABSTRACT FROM AUTHOR]

To investigate the influence of surface morphology on the electrochromic (EC) properties of indium oxynitride (InON), thin films were deposited on indium-doped tin oxide substrates using direct current (DC) magnetron sputtering. A systematic assessment was conducted by varying the substrate temperature and bias voltage to evaluate their respective impacts on the surface morphology and EC properties of InON. It was observed that as the substrate temperature gradually increased, the optical modulation showed a trend of initial increase followed by a gradual decrease. This nuanced behavior highlights the sensitivity of InON films to variations in deposition conditions. Additionally, the application of bias voltage induced significant alterations in the film's surface morphology, particularly noticeable when a negative bias voltage was employed. This resulted in a decrease in the transmittance, revealing the profound impact of bias voltage on the EC behavior of InON films. The wavelength range of InON electrochromism was also intricately linked to surface morphology. Optimal EC performance was consistently achieved when the surface exhibited minimal roughness, uniform particle distribution, and uniform film growth. These findings emphasize the importance of meticulous control over deposition parameters to attain better EC properties in InON films. More importantly, the study establishes that the EC phenomenon in InON films is primarily driven by ion migration through voids caused by alternate surface adsorption. This mechanism is similar to the observed behavior in InN films, providing valuable insights into the underlying processes governing electrochromism in InON films. These findings contribute to a deeper understanding of the factors influencing EC behavior in InON films and pave the way for enhanced applications in EC devices. [ABSTRACT FROM AUTHOR]

ZnO:F thin films were produced by ultrasonic spray pyrolysis (USP) technique. For photovoltaic and photocatalytic applications, the properties of ZnO films have been tried to be improved by adding the flourine (F) element. The average optical transmittance was higher than 85%. Photoluminescence (PL) spectra depict blue, green and yellow emission in deposited films. Photocatalytic activity of ZnO and ZnO:F thin films was evaluated with methylene blue (MB) organic pollutant under UV irradiation. 5% doped ZnO:F film successfully decomposed ~ 80% using MB as photocatalyst. The lowest resistivity (3.54 × 10–3 Ωcm), high carrier concentration (2.52 × 1020 cm−3) and high hall mobility (8.28 cm2V−1 s−1) were observed in ZnO:F (5%) film. With this study, it was concluded that F-doped ZnO films were effective in the degradation of MB, which is widely used in the food and pollutant industries. Therefore, it makes ZnO:F films a promising material in both optoelectronic and photocatalytic applications due to their optimum properties. [ABSTRACT FROM AUTHOR]

Herein, bismuth telluride (Bi2Te3) thin films thermally grown under vacuum have been integrated with p-Si in a heterojunction configuration of Au/Bi2Te3/p-Si/Al for resistive switching random-access memory (RRAM) applications. The quality of the grown films was evaluated in terms of crystal structure and films' morphology using XRD and FE-SEM techniques, respectively. The dark I-V under sweeping cycles between ± 5 Volts revealed the bidirectional RRAM features. The heterojunction parameters are extracted using Thermionic emission and Cheung-Cheung models. The conduction mechanism under forward/reverse biasing is discussed, emphasizing the impact of the interfacial states profile on the junction performance. Furthermore, the AC spectroscopical features of the designed heterojunction have been tested under different modulating frequencies, declaring a nontrivial capacitance behavior (i.e., negative capacitance). Based on the recorded (C-V) data at different frequencies, the built-in potential, Vbi, depletion region width, Wd, acceptor doping concertation, NA, and barrier height, ΦB, are evaluated. The extracted Vbi, Wd, NA, and ΦB magnitudes at 1 MHz were about 0.6 Volt, 1.06 μm, 7.16 × 1026 cm−3, and 1.095 eV, respectively. Ultimately, the Re [Z]-Im [Z] plot showed an interesting switching plot behavior with notable promising negative capacitance features. This astonishing performance of the fabricated heterojunction suggests this design for memristor applicability. An exciting [Re [Z]-Im [Z]] relation plot that may be useful in fabricating electrical switching electronic devices by using the frequency of the applied AC signal as a probe controlling factor (10 kHz to 7 MHz). [ABSTRACT FROM AUTHOR]

CIGS thin film solar cells have attracted extensive attention due to their high conversion efficiency (the highest conversion efficiency of 23.35%). The electrodeposition method is widely used to prepare CIGS thin films because of its simple process, fast deposition rate, low equipment cost and high material utilization rate. However, the aggregation of Ga, poor crystallinity and the interface recombination led the poor conversion efficiency of 17.3%. In this work, pulsed optic-thermal coupling process was employed to improve the film quality and device performance. With the pulsed optic-thermal coupling process, the surface temperature of film could rise to 550 ℃ in few seconds, which suppressed the prefer reactions between In-Se and Ga-Se. Large-grained CIGS thin films were prepared with fine grains at the back contact eliminated, which improved the crystallinity. The performance of CIGS thin film solar cells was also improved with a conversion efficiency of 9.14% being obtained with the optimized pulsed optic-thermal coupling process. [ABSTRACT FROM AUTHOR]

In this work, we report magnetic and optical anisotropies in tilted nickel (Ni) nanocolumns and their dependencies on the film growth conditions. The Ni nanocolumns were prepared using electron beam evaporation technique in conjunction with glancing angle deposition methodology. The film depositions were performed at various in-situ substrate temperatures viz. 30 °C, 150 °C, 250 °C and 300 °C. An increase in material density with in-situ substrate temperature due to the thermal diffusion mediated coalescence of neighbouring grains was observed. The results were further corroborated with the alterations in surface morphology of the films. The modification in tilt angle of the Ni nanocolumns was also observed with in-situ substrate heating due to the non-ballistic growth approach. The presence of uniaxial optical anisotropy was established in the films deposited at low substrate temperatures (< 250 °C) using generalized ellipsometry (GE). However, the uniaxial optical anisotropy was found to be negligible for the high temperature deposited films due to thermal diffusion effect. SQUID measurements were performed for quantification of magnetic anisotropy in the films. The estimated magnetic anisotropy energy confirmed low substrate temperature deposited films to be more anisotropic as compared to others. Magnetic coercivity of the films showed film porosity dependent changes in the field values. Overall, the present investigation demonstrates anisotropic behaviour of nanocolumnar nickel thin films for non-ballistic glancing angle deposition. [ABSTRACT FROM AUTHOR]

Cadmium telluride (CdTe) solar cells have attracted a lot of interest in recent years, attributed to their low cost and eco-friendly fabrication technique. However, the back contact is still the key issue for further improvement in device performance due to the work function difference between p-CdTe and metal contacts. In this study, the interatomic characteristics of zinc telluride (ZnTe) and Cu-doped ZnTe (ZnTe:Cu) as a back surface field (BSF) in CdTe structure is investigated using first-principles density functional theory (DFT) to overcome the Schottky barrier in CdTe solar cells. The incorporation of different doping levels of copper (Cu) in ZnTe on an atomic scale, where Zn1−xTe:Cux (x = 0, 2, 4, 6, 8, and 10) as the potential back surface field layers is investigated. The effect of doping concentration on electrical characteristics such as bandgap structure and density of states (DOS) were examined via ab initio with the Hubbard U (DFT + U) correction. The results showed an interesting gradual decrease in the bandgap energy of ZnTe from 2.24 eV to 2.10 eV, 1.98 eV, 1.92 eV, 1.88 eV, and 1.87 eV for the incremented value of Cu content of 3.13%, 6.25%, 9.38%, 12.50%, and 15.63%, respectively. Accordingly, it has been found that controlling of the effective copper doping, i.e., concentration, is crucial for developing efficient back contact junctions for high-efficiency CdTe thin-film solar cells. [ABSTRACT FROM AUTHOR]

In the current study, PbO thin films were produced using the economical chemical bath deposition (CBD) technique. To determine the impact of annealing temperature, PbO thin films were calcined at 200 °C, 300 °C, and 400 °C. Different characterization techniques were used to assess the properties of PbO thin films. The XRD result demonstrates that both the α- and β-PbO phases are present in the deposited PbO films. The average crystallite size of the as-deposited PbO films was 36.50 nm. The average crystallite size for PbO films annealed at 200 °C, 300 °C, and 400 °C was 38.26, 48.48, and 51.34 nm, respectively. According to the UV–Vis result, the PbO film's energy band gap was 3.44 eV, 2.80 eV, 2.61 eV, and 2.24 eV for as-deposited, 200 °C, 300 °C, and 400 °C, respectively. PbO thin films annealed at 200 °C and 300 °C showed a prominent green band emission at 523 nm, according to photoluminescence spectroscopy. Nevertheless, it exhibits a red shift of 524 nm for as-deposited and annealed at 200 °C. The SEM analysis demonstrated the irregular and nanorod morphological distributions of particles on the surface of the substrates. The purity of the produced PbO thin films as well as the presence of Pb and O in their composition was verified by EDX. Based on the obtained characterizations results, the produced PbO thin films can be used in solar cells and for photocatalysis. [ABSTRACT FROM AUTHOR]

In this study, researchers investigated the potential of nanostructured gadolinium-doped bismuth ferrite (Bi0.9Gd0.1FeO3) thin film as an electrode material for supercapacitors. The thin film was synthesized using the sol–gel method and deposited onto a Si/SiO2/TiO2/Pt substrate using spin coating. X-ray diffraction (XRD) measurements confirmed a rhombohedral distorted perovskite structure. Morphological analysis with SEM and AFM revealed the presence of nanorod-like structures, approximately 200 nm thick. FTIR spectroscopy confirmed the functional groups in the film. Through electrochemical measurements, including cyclic voltammetry (CV), galvanostatic charge and discharge (GCD), and electrochemical impedance spectroscopy (EIS), a significant specific capacitance of 812 F/g was observed, indicating promising supercapacitor performance through superficial faradic reactions. The findings suggest that gadolinium-doped bismuth ferrite thin films hold potential as effective electrode materials for supercapacitors when operating in a liquid environment. [ABSTRACT FROM AUTHOR]

Thin-film semiconductors based on Ag-doped Sb2O3 are promising prospects for the creation of future-generation high-efficiency, low-cost solar cell systems. This is due to their high absorption coefficient and good optical characteristics in the visible region of the solar spectrum. The thin film was optically characterised under various composition and deposition circumstances. Aside from the materials used in cell manufacture, the performance of solar cells is also affected by the deposition technique and parameters. In this study, thermal evaporation was used to create pure Sb2O3 and Sb2O3 doped with Ag thin films with different thicknesses (18, 25, 28, 32, and 36) nm. The X-ray diffraction examination revealed that all of the films were polycrystalline, in nature with a strong (400) plane as the preferred orientation, The importance of Sb2O3:Ag thin film is the change of band gap when incorporating Ag into the Sb2O3, the optical measurements show that the pure and doped Ag thin films allowed a direct energy gap that was decreased from 3.2 eV at thickness 18 nm to 3.1 eV at thickness 36 nm for Sb2O3:0.006%Ag. This shift in the energy gap suggests using Sb2O3:Ag thin film for solar cell applications. While the absorbance of thin films increased as Ag-doped content increased, making these films more suitable for solar cell fabrication. [ABSTRACT FROM AUTHOR]

Simplified two-electrode electrochemical deposition technique with glass/tin-doped indium oxide (glass/ITO) has been used to grow Mg-doped CdS thin films. As precursors, CdCl2, MgCl2 and Na2S2O3 were utilized. To study the physico-chemical properties of the obtained Mg-doped CdS thin-film instruments such as grazing incidence X-ray diffraction and Raman spectroscopy for structural analysis, UV–Vis spectrophotometry for optical properties and scanning probe microscopy for morphological properties have been used. It is observed from grazing incidence X-ray diffraction (GIXRD) data that the films are polycrystalline with only hexagonal phase. Because more metallic ions are deposited on the substrate, the material becomes more crystalline and increases the intensity of distinctive peaks observed. From the obtained optical characterization, it is observed that deposition time significantly influences the bandgap of the film. As deposition time raised from 10 to 25 min the bandgap decreases from 2.44 to 2.39 which makes the film to become more transparent and absorbs less light at shorter deposition times. According to scanning electron microscope (SEM) images, the surface morphology is uniform with tightly packed grains, and as deposition time goes on the grain shapes become less apparent. [ABSTRACT FROM AUTHOR]

In this paper, we report the electrical properties of Al/p-Cu2ZnSnS4 thin film Schottky diode fabricated by a two-step method. Cu2ZnSnS4 ingot was successfully grown by direct melting of the constituent elements, then (CZTS) thin film was grown using thermal evaporation method onto heated Mo substrate temperature at 100 °C. After that, the as-deposited CZTS sample were annealed in a sulfur atmosphere at 400 °C for 30 min. X-ray diffraction analysis reveals a polycrystalline CZTS preferentially oriented along a (112) plane in kesterite structure. For bulk material, the band gap energy is about 1.39 eV, the complex impedance plots display a semicircle with an equivalent circuit consisting of a parallel RC circuit connected to a series resistor. The CZTS thin film was investigated in the way of structural and electrical properties. Raman spectra ensured formation of kesterite CZTS phase. Dense and polycrystalline surface features were observed in SEM images of CZTS thin film. The I–V characteristics showed that a Schottky contact was obtained between Aluminum and p-Cu2ZnSnS4 absorber layer. Characteristic parameters such as saturation current, ideality factor and series resistance were calculated from the experimental I–V data. These parameters showed significant electrical properties such as low series resistance and an ideality factor between 1 and 2. Finally, the Arrhenius diagram provided a very low activation energy of about 2.03 meV. [ABSTRACT FROM AUTHOR]

YBa2Cu3Ox (YBCO) thin films were deposited on 14°–22° tilted-axes NdGaO3 (NGO) substrates with pulsed laser deposition. Two orientations of the film are possible due to the presence of symmetrically equivalent (110) and (1 − 1 0) facets on the substrate surface. At high deposition rates, the pseudo-a grains, (100)YBCO||(110)NGO, gradually overgrow the pseudo-c grains, (001)YBCO||(110)NGO, forming high-tilted (tilt angle of the c axis 69°–74°) YBCO films. The substrate tilt angles in the vicinity of 18.43° promote formation of high-tilted films as a result of graphoepitaxial seeding of the pseudo-a grains on the (110) facets on the substrate surface due to the matching of the c lattice constant of the film with the length of the (110) terraces on the substrate surface. The effect of graphoepitaxial seeding was observed for the substrate tilt angles in the range 16°–21°, probably due to undulating edges of steps on the substrate surface. An increase of the deposition rate above a threshold level of ~ 3 nm/s results in a change of the growth mode with the formation of films with smooth surface morphology. The probable reason is a transition from vapor phase epitaxy to vapor–liquid–solid crystallization mechanism. The tilted-axes YBCO films demonstrate superconducting transition temperature superior to standard samples fabricated on (110) NGO substrates. The width of the superconducting transition for tilted-axes films increases due to the suppression of the critical current in the direction normal to the tilt axis. [ABSTRACT FROM AUTHOR]

The substance Ag3SbS3 could be a viable option guaranteeing extraordinary performance for electrodes with high storage capacity, but also for solar cell absorbents. For optimal manufacturing, Ag3SbS3 thin films were electrodeposited on Fluorine-Tin Oxide (FTO) and then sulfurized at different temperatures. Structurally, XRD and RAMAN analyses confirmed that hexagonal polycrystallization of the Ag3SbS3 phase is only effective for sulfurization at 475 °C. After elaboration, the thin films were analyzed morphologically, optically and electrochemically to better define their physicochemical performances. Cyclic voltammetry (CV) analysis proved that the co-electrodeposited Ag3SbS3/FTO electrode has a pseudo-capacitor behavior in Li2CO3 (0.5 M) under the [− 700, 0 mV] potential window, developing a specific capacitance of more than 810 F/g. Furthermore, the galvanostatic charge–discharge (GCD) confirms this pseudo-capacitor behavior and that by varying the current from 1 to 5 mA, the specific energy decreases slightly from 14.5 to 11.1 Wh kg−1 to the inverse of the specific power, which varies from 175.1 to 875.3 W. k g−1. Finally, the DFT calculation executed within the framework of generalized gradient approximation (GGA) with a modified Becke-Johnson exchange–correlation potential (mBJ) predicts results extremely comparable to those discovered experimentally and which are precisely an optical gap and an absorption coefficient of the order of 105 cm−1 and 1.62 eV, respectively. All of this enabled us to conclude that Ag3SbS3 possesses the physicochemical characteristics to make it an attractive option in the disciplines of supercapacity as well as photovoltaic. [ABSTRACT FROM AUTHOR]

In this study, we employed the flash thermal evaporation method to create thin films of CsPbBr3 doped with Zn2+ thin film as an emitting layer, aiming to boost the performance of LED devices. ZnBr2 was added to CsPbBr3 powders at different concentrations (0%, 5%, 10%, 15%, and 20%), using it as a sole source material for vacuum thermal evaporation. It was found that with the incorporation of 10% Zn2+, the photoluminescence intensity of the film was 2.5 times higher than that of the undoped CsPbBr3 film. As a result, the LED based on 10%- Zn doped CsPbBr3 emitter layer shows the highest luminance and current efficiency of up to 5000 cd m−2 and 5.89 cd × A−1, respectively at 4.8 V, which is much higher than that of the device based on CsPbBr3 (1321 cd m−2 and 0.09 cd × A−1). The findings of this research are anticipated to benefit future perovskite LED studies using single-source thermal evaporation. [ABSTRACT FROM AUTHOR]

The influence mechanism of tensile load on the conductivity of thin films is a key issue in evaluating the conductivity of engineering structural thin films under complex loading conditions. How to reveal the correlation mechanisms of different physical quantities of metal films, and to predict the variation of film resistance with tensile load is a very critical and challenging problem. In this paper, a multiscale model of film resistance under tensile neching is established to describe the mechanical behavior, resistivity, and resistance of metal films under tensile load. The results show that the tensile load has a significant effect on the resistivity and conductivity of the film. This provides a reference for the evaluation and optimization of the conductivity of thin films with complex engineering structures. [ABSTRACT FROM AUTHOR]

The ZIF-67@Ag/TiN composite films were synthesized by in situ growth method and used as a noble substrate for surface enhanced Raman spectroscopy (SERS). The composition, morphology, optical properties and SERS performance of the composite films were characterized. The XRD, SEM and EDS results show that face-centered cubic TiN crystal, face-centered cubic Ag crystal and ZIF-67 triple-phase material was formed in the films. The ZIF-67 nanoparticles have an orthorhombic structure with a diameter of about 500 nm, which gives the composite films porous structure and might adsorb more probe molecules. The ZIF-67@Ag/TiN composite films have superior Raman enhancement performance with a detection limit of 10–12 M and an enhancement factor of 8.71 × 107 for the probe molecule R6G. In addition, the ZIF-67@Ag/TiN composite films have good homogeneity and long-term stability. [ABSTRACT FROM AUTHOR]

The facile and cost-effective chemical bath deposition (CBD) method is used to synthesize highly photoactive facet-controlled bismuth vanadate (BiVO4) thin films on glass and stainless steel (SS) substrates. The facet-controlled BiVO4 thin films are synthesized by variation in anionic precursor with fine tuning of chemical bath pH from alkaline to acidic media. The variation of anionic precursor evolves the morphology of BiVO4 from dispersed nanoparticles to faceted microcrystals. Furthermore, the fine-tuning of chemical bath pH leads to the well-defined octahedral BiVO4 microcrystals. Compared to dispersed nanoparticulate BiVO4 photoanodes, the octahedral BiVO4 photoanodes demonstrated superior photocurrent density of 2.75 mA cm−2 (at 1.23 V vs. RHE), good photostability and charge separation efficiency (45.5%) owing to their excellent PEC reaction kinetics. The present study underscores the usefulness of the CBD method for facet-controlled synthesis of semiconducting thin films for different photo-functional applications. [ABSTRACT FROM AUTHOR]

This work reports the microstructuring of cobalt (Co) thin films by high-energy UV pulsed laser irradiation. The parameters responsible for the efficient formation of such microstructures include laser fluence and film parameters. Cracks and island formations were observed for Co thin films deposited by RF sputtering. Such rough films rendered to produce inefficient microstructuring. To overcome this limitation, Co thin films were deposited by vacuum evaporation resulting in a smooth thin film compatible for laser-induced microstructuring. Two stages of conical patterning are discussed in terms of localized melting and abrupt condensation of the melted Co film owing to laser irradiation. An efficiency of 90% for laser-based microstructuring suggests that it is an efficient and non-invasive technique for fabricating nanostructures. [ABSTRACT FROM AUTHOR]

A self-powered photodetector based on copper oxide thin film (Cu2O-TF) is deposited using the e-beam evaporation technique. One notable advantage of this fabrication process is that it does not require the use of any catalysts. The XRD analysis revealed the presence of cuprous oxide (Cu2O) with a distinct peak at ~ 42.66º indicating (200) orientation. SEM analysis confirms the successful growth of the Cu2O-TF, revealing a porous semi-spherical structure with a measured thickness of ~ 100 nm. Moreover, electrical analysis was studied for the voltage range of − 2 to 2 V. The Cu2O-TF device exhibited a rectification ratio (RR) of 64 at + 1 V. Notably, the device exhibited self-powered characteristics, showing a stable switching response characterized by rise time (τr) values of ~ 0.183 sec and fall time (τf) of ~ 0.236 s at 0 V. Furthermore, the device obtained maximum responsivity in the near IR region, extending from ~ 700 to 800 nm, with peak intensity reaching ~ 720 nm along with responsivity values of ~ 6.6 mA/W. Moreover, the device obtained a detectivity value of ~ 3.45 × 1011 Jones and a low-noise equivalent power of ~ 8.12 × 10–12 at 0 V. The overall results highlight the suitability of the device for self-powered photodetector applications. [ABSTRACT FROM AUTHOR]

We have demonstrated a comparative study of NO2 gas sensing behavior of reactive sputtered growth WO3−x nanocrystalline thin films and its functionalization with Ag nanoparticles (Ag−WO3−x) on Si/SiO2 substrates. X-ray diffraction and transmission electron microscope characterizations demonstrate the formation of polycrystalline monoclinic phase of porous WO3-x thin film. X-ray photoelectron spectroscopy experiments reveal that W6+ charge state has higher concentration compared with that of W4+ and W5+. The Ag−WO3−x films exhibit a sensitivity of about 70% at 10 ppm, while WO3−x films show 12%, measured at 225 °C with same NO2 gas concentration. The response and recovery time are 2 and 3 min. for Ag−WO3−x films, while these for WO3−x films are 3 and 4 min., respectively. This work shows that nano-scale dendritic agglomeration growth of Ag nanoparticles on WO3−x surface can increase active sites for NO2 gas and play an important role in trace-level gas sensing performance. [ABSTRACT FROM AUTHOR]

Copper–zinc sulfide (CZS) is a ternary earth-abundant and non-toxic material having a wide range of optoelectronic applications. This investigation presents the bipolar-switching characteristics of CZS-switching layer-based devices for resistive memory-switching applications. The material was deposited on the fluorine doped tin oxide (FTO) substrate by spray pyrolysis method at a substrate temperature of 350 °C. Structural analysis indicate that the as prepared films consists of a composite structure of CuS and ZnS phases. The deposited films are p-type in nature. Resistive memory-switching devices are fabricated with the structure of FTO/CZS/Ag. The observed ON/OFF ratio of ~ 320 suggests that the device possesses good memory-switching properties. The formation and rupture of the conductive filaments of the FTO/CZS/Ag memory device were detected from the hysteresis curve. This confirms that CZS material can be used as the switching layer to fabricate a simple, cost-effective, and non-toxic bipolar device, which can deliver the perfect switching characteristics. [ABSTRACT FROM AUTHOR]

Copper oxide thin films were grown on (111)-oriented MgO substrates via the DC magnetron sputtering technique. High-purity copper was used as target material. The films were grown in an atmosphere of pure argon at a pressure of 1.27 torr. The substrate temperature was maintained at 400 °C during the growth. After deposition, the films were annealed in-situ in an argon/oxygen atmosphere (80%/20%) at 450 °C for either two or four minutes. It was found that the annealing time was a sensitive process parameter for achieving single- or mixed-phase copper oxide thin films. The single-phase cuprous (Cu2O) oxide films were obtained with the shorter annealing time (two minutes). Longer annealing times led to destabilization of the Cu2O phase, concomitant with the formation of the cupric oxide (CuO) phase in the sample. From optical spectroscopy studies, a band gap value of 2.4 eV was determined for the Cu2O films. This value decreased for the mixed-phase films. Near-infrared spectroscopy spectra were characterized by the presence of troughs and peaks, probably stemming from volume and surface scattering. Furthermore, differences in the intensity of the absorption with the chosen annealing process were observed, which were probably associated with slight variations in the grain size and/or morphology of the films. The electrical behavior of the films was investigated by means of complex impedance spectroscopy and DC transport measurements. Strong dependence of the electrical properties on the frequency and temperature was observed. The impedance spectra were well modeled in terms of equivalent electrical circuits. As a result, it was found that the predominant contribution to the resistance and capacitance of the Cu2O films came from the bulk of the grains. It was also verified that the relaxation of the charge carriers was a thermally active process with an activation energy of ~ 0.17 eV. A semiconducting-like behavior in the 100–320 K temperature range was also verified. The electronic transport mechanism in the Cu2O films was satisfactorily described within the framework of the Mott variable range hopping model. From the fit of this model to the experimental data, values as high as 3.5 × 1018 eV−1 cm−3 and ~ 12 nm were estimated for the density of states at the Fermi level and the hopping distance, respectively. [ABSTRACT FROM AUTHOR]

There has been tremendous research progress among scientists in the development of hybrid solar cells (HSC) as green solar energy. The research aims to investigate the influence of several types of transparent conductive electrodes on the performance of fabricated HSC. Single-layer graphene (SG)-based film has been identified as a potential replacement for indium tin oxide (ITO)-based film as anode transparent conductive layer (ATCL) in HSC. In this work, we have fabricated ITO-based HSC (ISc), SG-based HSC (GSc), and heat-treated SG-based HSC (HGSc). It was observed that the power conversion efficiency (PCE) was significantly dependent on the types of ATCL. These significant findings are measured by Raman spectroscopy, a UV–Vis spectrophotometer, and a solar simulator. The HGSc possesses the best PCE of 1.960%, compared to 1.225% in the ISc, with an open-circuit voltage (Voc) of 0.5 V, a short-circuit photocurrent density (Jsc) of 11.2 mAcm−2, and a fill factor (FF) of 0.35. The properties of heat-treated SG-based film were significantly attributed to PCE enhancement in HSC. As a conclusion, the use of graphene-based film has opened up a new research interest in the solar cell fabrication process. [ABSTRACT FROM AUTHOR]

Nickel oxide (NiO) thin films were grown on glass substrate by direct current magnetron sputtering at different oxygen (O2) partial pressure. The influence of O2 partial pressure on the structural, optical, and electrochromic properties of NiO thin films were investigated. A strong relation between O2 partial pressure and NiO film properties such as optical transparency, crystallinity, grain size, lattice constant and the electrochromic properties was realized. The evaluation of the X-ray diffraction peaks indicated an increase with the in-plane lattice constant with the direction of (200) resulting in a strain on the NiO films. Both Ni2+ and Ni3+ were observed in NiO thin layers from X-ray photoelectron spectroscopy results and their concentration varied according to the O2 partial pressure. Optimization of O2 partial pressure led to reach the highest electrochromic efficiency of 53 cm2/C and optical transmittance variation of 51%. [ABSTRACT FROM AUTHOR]

In this research study, TiO2 thin films-based ethanol sensors were fabricated by RF magnetron sputtering technique. The devices' structure, surface morphology, and sensing performance were engineered by changing the sputtering power. The characteristics of sensing materials were studied by grazing incidence X-ray diffraction (GIXRD), atomic force microscopy (AFM), and field emission scanning electron Microscopy (FESEM). The produced samples at low powers (100 and 200 W) had a tetragonal structure with a mixed phase of anatase and rutile whereas the sample deposited at the power of 300 W represented a single phase of anatase. The results showed that the variation of sputtering power had a significant effect on the ethanol vapor sensing performance of the devices due to the change in crystallographic structure, phase, and surface morphology. The sample produced at the sputtering power of 200 W showed more sensitivity than the other samples. The mentioned device also showed enhanced sensitivity compared to the previous reports due to its dual structure. [ABSTRACT FROM AUTHOR]

An FTO thin film was first deposited onto a glass substrate via the spray pyrolysis technique. To investigate the influence of the used salt and, consequently, structural properties on electrochemical performance, two precursor solutions were prepared from copper chloride dihydrate and copper acetate monohydrate and spray-deposited onto the FTO thin films. Considerable differences were observed in the physical characteristics of the resulting CuO thin films derived from different precursor solutions. The XRD results were employed to estimate the crystallite size and strain for the prepared CuO thin films via the Williamson–Hall method, as well as lattice parameters. Accordingly, the CuO thin film deposited from chlorine salt showed a greater crystallite size, lower strain, and unit volume cell. The Hall effect measurement revealed that there is slightly less resistivity for the CuO prepared from chlorine salt; however, mobility and carrier concentration were significantly different for the CuO thin films. The Randles–Sevcik equation was used to calculate the diffusion coefficient, and it is found that the structural characteristics of CuO grown from acetate salt (6.43 × 10–6 cm2/s) are in favor of better ion diffusion in compare with chloride salt (4.72 × 10–6 cm2/s). Similarly, the estimated equivalent distribution resistance from the Nyquist plot for CuO thin films spray-deposited from chlorine (250.11 Ω) and acetate (130.01 Ω) confirmed the better ion diffusion for the acetate solution-derived CuO thin film. Capacitance was calculated from cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy, all of which confirmed better ion storage performance in CuO deposited from acetate salt due to the superior ion diffusion characteristics of the mentioned thin film. [ABSTRACT FROM AUTHOR]

Rare earth (R) and transition metal (T) based films are potential magnetic materials for a variety of applications. However, their structural and magnetic behavior is sensitive to growth and processing parameters. This article presents a comprehensive investigation aiming to analyze the microstructure and magnetic properties of NdFe/MgO(001) films. These films were fabricated by evaporating nanocrystalline Nd3Fe29 powder at different thicknesses (t) and subjected to various heat treatments (Ta). The main objective of this research is to gain a detailed understanding of how the structural and magnetic behavior evolves based on these parameters, which had not been achieved previously. X-ray diffraction analysis was employed to determine the crystalline structure of NdFe/MgO(001) films and to track the grain size evolution with film thickness. Scanning electron microscopy (SEM) and magnetic force microscopy (MFM) images were used to directly visualize magnetic domains and the arrangement of magnetic grains at different thicknesses. Ferromagnetic resonance (FMR) measurements revealed significant variations in resonance fields and easy axes depending on film thickness and heat treatments. The study also examined how magnetic properties such as saturation magnetization (Ms) and coercivity (Hc) are closely related to grain size, magnetic domain organization, and heat treatments. Our research produced remarkable results, especially concerning a 250 nm thick NdFe/MgO(001) film annealed at 873 K, which exhibited outstanding properties. These properties include a robust coercivity of 5230 Oe, a substantial remanent magnetization of 211 emu/cm3, a magnetic anisotropy field of 10,325 Oe, a saturation magnetization (Ms) of 396 emu/cm3, and a Curie temperature of approximately 388 K. It's noteworthy that this film possesses an easy magnetization axis parallel to the film plane (HFMR(∥) = 9125 Oe > HFMR(⊥) = 5897 Oe). Although the study provides valuable insights for the design and optimization of magnetic materials for various technological applications in the field of magnetism, its limitation should be acknowledged. The research did not deeply explore the correlations between the different studied properties, leaving a gap in our overall understanding of these characteristics. Therefore, future work will focus on conducting simulations and theoretical modeling to address this research gap. [ABSTRACT FROM AUTHOR]

In the current research, spray pyrolysis was effectively employed to create the ZnSnO3 and Cr: ZnSnO3 films at substrate temperature 320 °C. The X-ray diffraction spectra of the ZnSnO3 and Cr: ZnSnO3 thin films revealed a rhombohedral structure corresponding to the ZnSnO3 phase. The structural analysis refers to increasing the Cr content from 0 to 7.5 wt% led to a reduction in the crystallite size of the investigated layers from 36.92 to 23.87 nm. The EDX measurements verified the existence of the Zn, Sn, and O in the ZnSnO3 and Cr, Zn, Sn, and O in the Cr: ZnSnO3 thin films. The ratios of these elements match the stoichiometry of ZnSnO3. Spectrophotometric measurements of the transmission and reflection of the neoteric Cr: ZnSnO3 sheets were used for analyzing their optical characteristics. The optical transmissions of the ZnSnO3 and Cr: ZnSnO3 films were reduced from 94 to 81% by boosting the Cr content. Moreover, the studied films attained band gaps reduced from 3.71 to 3.29 eV, boosting the Cr content from 0 to 7.5 wt%. Also, the analysis of the refractive indices of the investigated films displays an improvement in these values from 2.43 to 3.75. The Urbach energy of these samples increased from 0.13 to 0.17 eV by enlarging the Cr content. The optoelectrical indices like electrical conductivity, real and imaginary sections of the dielectric indices, and optical conductivity are all boosted by boosting the Cr content. The impact of Cr content on the nonlinear optical parameters refers to an enhancement in the nonlinear optical parameter's values. [ABSTRACT FROM AUTHOR]

This work systematically investigates the improvement in phase change properties and crystallization mechanism of Sb films after Y doping. Compared with the pure Sb thin films, Sb51Y49 has a higher crystallizing temperature (203 ℃) and longer failure time (766 s), indicating that Y doping can enhance the thermal stability of the material in the amorphous state effectively. Y exists in an amorphous state and has an inhibitory effect on grain growth, resulting in smaller grain sizes in Y-doped Sb films. The crystallization mechanism was investigated using the Johnson–Mehl–Avrami model, and the crystallization mechanism of the Sb films before and after Y-doping is unchanged and always dominated by growth, a property that is favorable for achieving fast phase transitions. The phase change cells based on Sb51Y49 films exhibit a lower energy consumption (3.5 × 10–11 J) than the conventional Ge2Sb2Te5 material. The findings demonstrate the potential of Y-doped Sb as a phase change material with excellent crystallization rate and energy consumption performance. [ABSTRACT FROM AUTHOR]

The study investigates the impact of nickel doping on the structural, optical, morphological, and gas sensing properties of zinc oxide (ZnO) thin films. Films were synthesized using a spray pyrolysis technique on a glass substrate. Structural and morphological analyses were conducted through X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). XRD revealed a hexagonal wurtzite structure, primarily aligned along (101) planes. However, nickel doping prompted a preferred orientation towards (002) plane. Lattice parameters decreased systematically, due to the ionic radii mismatch between dopant and host. FESEM showed a nanoflake morphology. Compositional analysis with energy dispersive X-ray spectroscopy (EDX) confirmed successful doping. Optical analysis using UV–Vis spectroscopy indicated high transmission in undoped ZnO films. However reduced band gap values have been reduced with nickel incorporation. Gas sensing response observed to be significantly improved with Nickel doping in ZnO. [ABSTRACT FROM AUTHOR]

The antibacterial ability of medical titanium alloy implant in vivo remains a significant challenge for orthopedic implants despite its excellent mechanical and osteoconductive properties. Here, we explored a simple method to improve the antibacterial ability of Ti6Al4V. The silver physically adheres to the surface of the structure by laser interference direct writing after coating the silver film by ion sputtering from 50 to 500 nm; meanwhile, periodic microstripe structure was formed, showing good antibacterial properties against the Gram-positive bacterial Staphylococcus aureus (S. aureus). Moreover, the antibacterial ability was increased with the increase of silver film thickness. While the silver film thickness was larger than 100 nm, the antibacterial rate exceeded 90%. In addition, the Ag+ releases concentration for Ag100nm, Ag300nm, and Ag500nm were also measured from 24 to 120 h, which showed the linear increment with the thickness of Ag thin film and release time. The surface of the structure showed the good bio-compatibility for the MC3T3-E1 cell; simultaneously, the growth of the cell was obviously adjusted by these microstripes. In summary, the Ti6Al4V with these microstripes after Ag modification combines good antimicrobial properties, bio-compatibility and cell growth regulation performance, which showed the potential application as an orthopedic implant in the future. [ABSTRACT FROM AUTHOR]

Magnetic cooling requires energy-efficient and eco-friendly alternatives to conventional rare earth element-based materials, which rely on materials with customized magnetic and structural properties. This study introduces the growth of iron oxide thin films for designing magnetocaloric materials, using a phenomenological model to screen candidates for the magnetocaloric effect (MCE) and inverse magnetocaloric effect (IMCE). Based on the Curie temperature (TC) window concept, ferrimagnetic Fe3O4 and the antiferromagnetic α-Fe2O3 and FeO thin films are identified as potential candidates for structural transitions (TV) and spin rearrangement (TN) achieved by manipulating their nanoscale ordering temperatures. These oxide films exhibit IMCE with a maximum entropy change (ΔSmax) ranging from 0.13 to 1.87 J/kg-K at TV and/or TN, while demonstrating the MCE effect at low temperatures. Interestingly, we demonstrate that IMCE can occur in Fe3O4 thin films without a structural transition but with a change in anisotropy. In addition, utilizing textured growth to tailor magneto-structural coupling in thin films is predicted as a novel approach for engineering magnetocaloric materials. [ABSTRACT FROM AUTHOR]

In this study pure and Mg, Ga, Al-doped ZnO thin films were prepared using sol–gel and spin-coating methods. The effect of dopant ion substitution on structural, morphological, optical and low temperature electrical properties of thin films were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), UV–Visible spectroscopy, spectro fluorophotometer and two probe resistivity measurement method, respectively. The XRD result confirmed the wurtzite structure of prepared thin films without the presence of any characteristic impurity peak of Mg, Ga and Al. The average crystallite size of ZnO thin film was found to be 22.17 nm which was found to decrease to 21.13 nm, 16.06 nm and 16.03 nm when Mg2+, Ga3+ and Al3+ ions substitutes Zn2+ ions, respectively. The photoluminescence study had confirmed the presence of defect states in the prepared thin films. Furthermore, the low temperature dependent electrical study had shown that Ga-doping decreased the electrical resistivity and confirmed the presence of thermally activated and hopping type conduction mechanism up to 100 K. Thus, the ability of Ga-doping to facilitate the conduction process down up to 100 K, low activation energy of 0.23 eV and high optical transmittance in Ga and Ga-Mg doped-ZnO thin films makes it a suitable transparent and conductive material for optoelectronic devices. [ABSTRACT FROM AUTHOR]

Domain wall (DW) statics and dynamics have been immensely studied for the last few decades in a disordered medium due to rich fundamental physics and spintronics applications. Here, we have studied the DW dynamics in Pt/CoFeB/MgO thin film with perpendicular magnetic anisotropy. We have observed an unusual behaviour in the DW dynamics which cannot be only explained via universal creep or depinning law. At low driving force, the sample follows the universal creep law; however, near the depinning field ( H d ), an excess velocity has been observed in DW dynamics in comparison to the usual creep law. We propose that, due to additional relaxation events near H d , the DW propagation length is increased and hence the DW velocity. The excess velocity has been modelled to a modified creep law. [ABSTRACT FROM AUTHOR]