International Journal of Nanoscience

An experimental investigation has been undertaken to explore a variety of properties of organic perovskite solar cells (OPSCs) that are distinct in their photovoltaic response. In this study, OPSCs were constructed using zinc oxide, ZnO and [6,6]-phenylC${}_{61}$-acid methyl ester, PCBM, as electron transfer materials (ETM), poly(3-hexylthiophene), P3HT, as hole transport material (HTM), and CH₃NH₃PbIX₂ as a photosensitizer, where X is either Cl or I. The structural and optical characteristics of the ETM and HTM layers and the perovskite materials of OPSCs were investigated. The $I$–$V$ and $P$–$V$ curves of each solar cell prepared in OPSCs were measured using an integrated cell tester. This comprises a photovoltaic $I$–$V$ measurement system and a solar simulation system. As a result of these results, the OPSC’s performance is evaluated. The calculations in this work suggest that the highest power conversion efficiency (PCE = 6.31%) was achieved in photovoltaic devices using CH₃NH₃PbI₃ as the effective absorber layer and ZnO with PCBM as the ETM layer. At a light intensity of 100 mW/cm², each OPSC cell was performed. Under the same conditions, the $I$–$V$ curves were evaluated for each OPSC device. By improving the selection of organic and inorganic active materials in the ETM layer, OPSC performance may be improved.

As a consequence of the regeneration of nanostructures and the development of a nanocomposite with excellent superhydrophobic properties, a simple flame treatment strategy was examined to increase surface roughness. Cotton soaked in ethanol was used as a flame source at temperatures ($>$350${}^{\circ }$C) for 30 s. The flame treatment operation takes place after the titanium dioxide (TiO${}_2)$ nanoparticles (NPs) have been treated with room temperature vulcanized silicone rubber (RTV-SR) liquid using a dip coating approach. X-ray diffraction (XRD), contact angle (CA) measurement, field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and energy dispersive spectroscopy (EDS) were used to describe the superhydrophobic surface. Resulting surfaces demonstrated that the water contact angle (WCA) of the superhydrophobic surface was 168 ± 2${}^{\circ }$, sliding angle SA (4 ± 1${}^{\circ }$).

The alloy 50Ag−50Mn (wt.%) was prepared using ball milling. After 50 h of milling, the samples were isothermally annealed for 1 h at a time at three different temperatures ranging from 350^∘C to 550^∘C. By analyzing the X-ray diffraction data, Rietveld refinement structure analysis was used to measure the lattice strain and crystallite size. The introduction of lattice strain and the decrease in crystallite size as a function of milling time may both contribute to the increase in coercivity. The analysis of superconducting quantum interference devices demonstrates the soft ferromagnetic behavior of as-milled and annealed Ag−Mn alloy. After being annealed at 350^∘C for 1 h, the 50Ag−50Mn alloy’s maximum coercivity was discovered to be 253 Oe.

In this research, titanium alloys including smart nitinol (NiTi) were studied. The (NiTi) alloy tends to emitting (Ni) toxic ions due to its low resistance to corrosion within the body conditions over time. For (NiTi) coating process, the magnetron plasma sputtering (DC) technique was used with Aragon gas ratio of (90%) and Oxygen of (10%) in order to coat the alloy with Tantalum and its Oxide (Ta₂O${}_5)$ thin films. This is one of the methods used to improve the biocompatibility and better adhesion stability of the membrane on the (NiTi) surface, since Tantalum and its oxides are biocompatible and are not affected by the body fluids. Hardness, corrosion and biocompatibility were tested. The results showed improvement in the nominated properties using this coating technique. The hardness for the non-coated sample was (630 Kgf/mm${}^2)$, meanwhile, the coated sample recorded (762 Kgf/mm${}^2)$ using sputtering power of (25 W) with a thickness of (226 nm). Tantalum and its precipitated oxides on a pillar of thickness (90.4–226 nm) also exhibited a biocorrosion enhancement, when it was immersed in a Simulated Body Fluid (SBF). The corrosion rate for the non-coated sample was (1.204 × 10${}^{-2})$, meanwhile for the coated sample, its value was (3.453 × 10${}^{-5})$ at sputtering power of (15 W), considered as the lower corrosion rate. The scanning electron micrographs also showed an increase in the biocompatibility for the coated nitinol alloys (NiTi) in comparison with the non-coated, ones since it showed a clear formation of Hydroxyapatite (HA) on the sample surface after immersion in the SBF. This behavior was confirmed by the XRD measurements, which presented higher HA peaks on the coated samples surface in comparison with the non-coated samples.

Well crystalline Ag/CdO nanocomposite has been synthesized via the solution combustion synthesis (SCS) route. The Ag/CdO nanocomposite has been characterized in term of X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Raman spectroscopy. The crystallinity of the as-synthesized nanocomposite was obtained by using XRD technique. The crystallite size of the nanocomposite was calculated by the Scherrer equation and was found to be 47 nm. The surface morphology was obtained by FESEM spectroscopy. The particles appear to be porous in nature and wool-like morphology was obtained. Raman band at about 278 cm${}^{-1}$ is because of the combination of transverse acoustic and optical phonon modes of cadmium oxide (CdO). Further, the Ag/CdO nanocomposite was used as a photocatalyst for the degradation of methyl orange (MO) dye. Results revealed that the photocatalytic activity of Ag/CdO nanocomposite for the degradation of MO dye increases with increasing the amount of photocatalyst. The rate constant, $k$ values for 100 mg, 150 mg and 200 mg of photocatalyst were 0.83, 2.21 × 10${}^{-3}$ min${}^{-1}$ and 3.81 × 10${}^{-3}$ min${}^{-1}$, respectively.

In this research, the explosive wire method is used to prepare silver nanoparticles and study their effect on two types of bacteria, E. coli and Staphylococcus aureus. The X-ray diffraction pattern of silver nanoparticles after deposition on glass pieces shows a peak of silver and silver oxide. The FE-SEM morphology of silver oxide particles shows small spherical-like clusters of irregular flower-shaped particles. Meanwhile, the AFM analysis of the silver nanoparticles shows that the average roughness of the aggregates is 57 nm and the average size of the nanoparticles is 20.92 nm. The study of the effect of silver nanoparticles on two types of bacteria, namely E. coli and Staphylococcus aureus, has shown that these nanoparticles have achieved a killing rate of 99% for both types of bacteria.

Zinc oxide nanoparticles in the form of particles and rods were synthesized using the hydrothermal method. The scanning electron microscopy (SEM) examination was performed. The results of the SEM tests showed the nanoscale size of zinc oxide nanoparticles was (75 nm) for particles and (150 nm) for rods. An X-ray diffraction examination was carried out, and a comparison was made between the diffraction pattern of the ZnO nanoparticle and the rods. The results showed that the ZnO nanoparticle is in the hexagonal wurtzite phase of the structure of the particles and rods. Zinc oxide nanoparticles (particles and rods) produced by the hydrothermal method have been used as an additive in polyvinyl alcohol (PVA) polymer matrix to form PVA–ZnO NPs composite thin films. The optical properties of the membrane were studied using ultraviolet–visible examination, which showed a decrease in the energy gap of the composite thin film compared to the pure membrane. While the electrical properties of composite thin film, including resistivity, mobility and majority carrier charge carriers of composite thin film, were measured using the Hall effect measurement. The results showed that zinc oxide nanoparticles have a higher conductivity than nanorods.

This study aims to analyze the spectral properties of plasma produced from rice husk(Rh) using the laser breakdown spectroscopy (LIBS) method. The plasma generation process used the fundamental harmonic (1064 nm) of a Q-switched Nd:YAG laser. Yttrium aluminum garnet (YAG) is a man-made crystalline material. The laser fired pulses with a duration of 10 ns and a repetition rate of 6 Hz. Thus, the energy outputs achieved were 50–200 mJ at the wavelength of 1064 (nm). The silica content in the rice hulls was verified using an XRF measurement, which revealed the presence of silica in the rice hulls in a high percentage. Precise beam focusing was achieved by focusing the laser on the target material. This target material is placed within an atmospheric environment at standard pressure settings. The electron temperature was derived using the Boltzmann diagram method by harnessing experimental data for the linear properties associated with the neutral lines (Si II), (O II), and ion lines (Si I). The use of analytical methodology led to the determination of electron temperature values from 0.79 eV to 1.16 eV for the fundamental harmonic of the laser. At the same time, the electron (ne) density was determined by analyzing the Stark broadening profile associated with the neutral silica line. Furthermore, the study included an additional dimension by determining the plasma properties (electron temperature and electron density) by adjusting the laser energy on the target surface longitudinally along the path of the plasma plume.

In this work, we studied the effect noble metal thicknesses, namely gold (Au), silver (Ag), and copper (Cu) on the surface plasmon resonance (SPR) characteristics for sensitive optical sensor and biosensor applications. SPR spectra for Au, Ag and Cu were widely studied in the Fresnel equation to calculate the total reflection, the wavelength ($\lambda )$ range from 500 nm to 700 nm with the angle of incidence ($𝜃)$ ranging from 0^∘ to 90^∘ and thickness of the film ($d)$ reaching from 30 nm to 70 nm. Analysis simulation (in MATLAB) has been made for SPR of three metals placed on the N_LASF9 glass prism and the sensing medium is the air. The properties of the angle of resonance ${𝜃}_{\text{SPR}}$ have been calculated from plotted reflectance via incident angle ${𝜃}_{\text{SPR}}$. The results give efficient detection in a change of reflection ($R)$ and full half width maximum FWHM. The minimum reflection was obtained (0.003 a.u.) at wavelength 700 nm and thickness $d$= 50 nm for gold Au at $\mathrm{\Delta }n$ = 0.0. The best FWHM was recorded at the wavelength (500 nm) at thickness (70 nm) for silver at $\mathrm{\Delta }n$ = 0.0, which was equal (0.1 nm).

The graded-refractive-index SiO₂ antireflective (AR) films were prepared using the sol–gel method. A monolayer with a porous nanonetwork structure was designed as the mixed volume ratio of 70:30 between the alkali- and acid-catalyzed SiO₂ sols. As the top layer, the hexamethylisilazane (HMDS) modified alkali catalyzed SiO₂ sols induced SiO₂ nanoparticles transforming from hydrophilic to hydrophobic nature. In comparison with the structures of monolayer and bilayer films, the AR properties and laser damage resistance were investigated in detail. By designing the nanostructures of the bottom and top layers, the graded- refractive-index SiO₂ film was obtained, consequently enhancing the AR performance. In the bilayer film, the transmittance reached $\sim$98%@532 nm and 97%@1064 nm, respectively, corresponding to the obvious reduction of reflectivity. The assembly of the bilayer SiO₂ film increased the laser-induced damage threshold by $\sim$30% from 25.3 J/cm² (monolayer) to 33.1 J/cm² (bilayer). The inducement of laser damage was further revealed by the analysis of morphological changes induced by laser damage, attributing to the initiator absorption of environmental contaminations. Therefore, the SiO₂ film not only provided a graded-refractive-index structure with good AR performance, but also had high laser damage resistance. The unique graded-refractive-index structure of SiO₂ AR films offers a new strategy for improving the performance of optical components in high-power laser systems.