In this paper, the effect of sulfur substitution by arsenic on the structural, optical properties of thin films of the trivalent chalcogenide Se66S44-xAsx at different concentrations (where x = 0, 8, 16, and 24 at %) was studied. Thin films with a thickness of (300±10 nm) were prepared using thermal evaporation of bulk samples. Structural examinations were performed using XRD and AFM techniques. All the studied film samples were amorphous in structure and the intensity of the crystalline parts was high in the range of 10-40. Also, in Atomic Force Microscopy (AFM). It was found that increasing the concentration of arsenic affects the structural parameters such as surface roughness, particle density, and average grain size. As the arsenic element increased by 0.24, the grains became more regular, and the particle density increased. UV-Vis measurements reveal that the prepared films' absorption in the spectral wavelength range from 200 to 1100 nm. It was found that increasing the arsenic content led to a change in the absorbance of the films. The optical energy gap of Se66S44-xAsx thin films was determined and it was found that increasing arsenic content affected the energy gap differently as it changed within the range (2.35-2.19 eV). The energy gap increased at concentrations of (8, 16%) while the energy gap decreased at concentrations of 24%.

This research introduces an innovative aptasensor for detecting alpha-fetoprotein with exceptional sensitivity and specificity, employing a novel MoS2/Fe3O4 composite fabricated through an advanced in-situ growth methodology. The composite exhibited a hierarchical flower-like structure with uniformly distributed Fe3O4 nanoparticles, confirmed by SEM, XRD, and Raman spectroscopy. The MoS2/Fe3O4 composite demonstrated a 66% increase in surface area (7.16 m²/g) compared to pristine MoS2, enhancing aptamer immobilization and electron transfer efficiency. Electrochemical characterization revealed a significant increase in interfacial resistance upon AFP binding, with a detection limit of 0.3 pg/mL and a dual linear range of 0.001–0.1 ng/mL and 0.1–100 ng/mL. The aptasensor showed excellent specificity, negligible interference from proteins such as CEA and PSA, and high reproducibility (RSD < 4.2%). Stability tests indicated 95% signal retention after 7 days and 87% after 30 days. Real sample analysis in spiked human serum achieved recovery rates of 96.8–102.3%. These findings underscore the potential of the MoS2/Fe3O4-based aptasensor as a cost-effective, reliable tool for early liver cancer diagnosis, with significant improvements in sensitivity and practicality over conventional methods.

The electrical and structural characteristics of BixSe100-x glasses (where x=5, 10, 15, and 25 at. %) were systematically investigated. Using the traditional Quenching of melts process, the amorphous BixSe100-x materials were created. Thin films of BixSe100-x have formed onto ultrasonically glass substrates that have been cleaned using thermal evaporation in a vacuum of approximately 10^-5 Torr. Here we show and discuss the results of four bulk glasses of BixSe100-x (where x=5, 10, 15, and 25 at. %) that were subjected to differential thermal analysis (DTA) under non-isothermal conditions. For the compositions under consideration, five separate methods were used to calculate the activations of the change from amorphous to crystalline. The crystalline phases obtained from differential thermal analysis (DTA), additionally, scanning electron microscopy (SEM) have been characterized utilizing x-ray diffraction. The glass forming factors kg are derived for the analyzed compositions. The relationship between electrical conductivity (σ) and composition, as well as annealing temperature (T) within the range of 300–400 K, has been examined for BixSe100-x (x=5, 10, 15, and 25 at. %) amorphous thin films. The electrical measurements acquired are ultimately analyzed in relation to the amorphous–crystalline change.

This work presents a hybrid study that employs Ultrasonic Spray method for the deposition of SnS absorber films and SCAPS-1D simulation method for the analysis of various solar cell topologies. Different deposition times have been employed to optimize structural, optics, and electrical properties. To evaluate their potential as absorber layers for solar cells, the films were analyzed by using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and tested for electrical performance. Complementary numerical simulations were carried out with SCAPS-1D in modeling ZnO:Al/i-ZnO/SnS2/SnS solar cell structures. Results showed that optimized SnS thickness of 2.5 µm and high carrier density improve the performance of the devices and with a maximum of 6.37% PCE when integrated with silicon substrates.

In present work, Cu2BaSnS4(CBTS) nanoparticles are reported solvothermally synthesized. The formation of single-phase trigonal structure of CBTS nanoparticles is confirmed by XRD and Raman spectroscopic analysis. SEM studies reveal that CBTS exhibits flower shaped structure self-assembling by nanosheets with uniform average thickness 30nm. CBTS materials show abroad absorption in the complete visible range, providing a band-gap value of 1.58eV, indicating potential applications in photocvoltaics. The excellent MB degradation efficiency of 93% under visible light within 100min is achieved, suggesting CBTS is a potential material for effective solar light photocatalytic application. Meanwhile, electrical properties are measured up to 675K, the value of Seebeck coefficient of CBTS material can reach to 111.42μV•K-1 , meanwhile the value of electrical conductivity is 18.24S·m-1 , indicating its potential for thermoelectric application.

This paper investigates the impact of reduced graphene oxide (rGO) addition on the structural and optical properties of ZnS nanocomposites. The study began with the synthesis of graphene oxide (GO) through the oxidation of natural graphite powder. This process involved using potassium permanganate in a mixture of sulfuric and phosphoric acids, maintained at 50°C for 48 hours. The reaction was terminated using hydrogen peroxide, followed by purification and drying, yielding 1.5 grams of GO. The preparation of ZnS/GO nanocomposites involved dissolving zinc acetate and varying quantities of GO in water, adjusting the pH, and incorporating sodium sulfide. This mixture underwent heating in an autoclave at 180°C for 12 hours, followed by washing and freezing, resulting in ZnS-RGO composites with differing GO contents. The resulting products were categorized as ZnS0rGO, ZnS-5rGO, ZnS-10rGO, ZnS-15rGO, and ZnS-20rGO. To characterize these composite samples, the researchers employed several analytical techniques, including thermogravimetric analysis (TGA), X-ray diffraction (XRD) analysis, X-ray Photoelectron Spectroscopy (XPS), and UV-vis spectroscopy. This comprehensive approach allowed for a thorough examination of the effects of rGO incorporation on the nanocomposite's properties. The X-ray diffraction (XRD) results showed increased diffraction intensity with higher rGO content, attributed to improved crystallinity. The crystallite size and lattice strain also increased, with rGO providing nucleation sites. Optical analysis revealed that rGO increased absorbance and decreased the optical band gap, likely due to enhanced free charge carriers. The extinction coefficient and nonlinear refractive index both increased with rGO content, attributed to rGO’s high polarizability and light-matter interactions.

The structure particulars of amorphous Ge2Sb2Te5 thermally evaporated on glass substrates, as well as films annealed at temperatures of 500 and 700 K have been studied by the considering of experimentally established facts obtained from X-ray analysis and Raman spectroscopy measurements. The Debye-Scherrer and Williams-Hall methods were applied to the X-ray diffraction data for estimate the size of crystallites, interatomic distances, dislocation density and structure distortion degree. The features of heat treatment effect on numerical values of the above quantities at a given temperatures have been established. The analysis of the spectral distribution of Raman scattering was measured at light frequencies between 40 ÷ 300 cm-1 . The rather extended nature of the identified bands suggests the presence of several vibrational modes, leading to the appearance of individual spectral bands. To determine the vibrational modes, a reduced intensity was constructed from the experimental Raman spectrum data and the Gaussian approximation was applied to the latter. Having a mind the results of published works, the vibration modes existing in the samples obtained immediately after the process of layer application were determined, as well as the chemical nature and structure elements corresponding to these modes forming the amorphous matrix. The vibration modes in crystallized layers after heat treatment at the given temperatures were determined, as well as the chemical bonds and structural units forming their local structure.

Using the thermal evaporation method, thin crystalline films of Sb2(Sx Se1-x)3 are produced at the substrate temperature of 300℃. The mixed powders of the Sb2S3 and Sb2Se3 is used as a source material. The influence of the S/Se component ratio on the morphology and structural characteristics of Sb2(SxSe1-x)3 thin films is investigated. As demonstrated by the results of X-ray energy dispersive spectroscopy, the formed films of Sb2(SxSe1-x)3 have a components ratio close to the stoichiometry. Besides, Morphological and structural analyses reveal significant differences in the surface morphology of Sb2(SxSe1-x)3 thin film absorbers, indicating that the properties of the films vary as a function of the S/Se composition ratio.

Zinc sulfide thin films were prepared using the economical spray pyrolysis process. A thin film of exceptional quality with a temperature difference of 300 °C to 400 °C is produced by optimizing variables such as concentration, flow rate, and nozzle to substrate distance. These films' optical characteristics and structure were examined. The deposited thin films displayed a direct and allowed transition, as indicated by the optical transmittance spectra. XRD analysis confirmed that the deposited thin films were polycrystalline with a cubic phase. This film can be used in solar cell applications since the band gap energy fluctuation is high enough, ranging from 3.42 to 3.81 eV.

The use of semiconductors based on abundant and less expensive materials in photovoltaic industry has grown since electricity consumption has increased, alloys such as Cu2ZnSn(S1-xSex)4 have recently attracted attention, due to its structural, optical and electronic properties which make it a very promising candidate as an absorber layer in photovoltaic applications. The lattice mismatch of Cu2ZnSn(S1-xSex)4 with Cu2NiGeS4 as substrate for solar cell architecture reveals that low Se content (0.1≤x≤0.4) is favorable, and thus, by reducing Se content from 40 to 10% induces a decrease in optical parameters such as refractive index from 5.475 to 3.834 for near-infrared wavelengths, and both extinction and absorption coefficients are from 0.478 to 0.211 and from 7.956×104 to 6.912×104 cm-1 , respectively, for almost along the visible spectrum. Additionally, the bandgap energy of Cu2ZnSn(S1-xSex)4 in kesterite structure increases from 1.267 to 1.442 eV at room temperature, while the compressive strain of the epitaxial layer reduces from 3.93 to 2.39% and from 4.62 to 3.17% on the growth plane and following the direction of growth, respectively.