International Journal of Nanoscience

Photovoltaic is one of the best low-cost alternative energy sources. In this paper, organic semiconductors were explored as light harvesters due to their extraordinary properties, but initially, the scientific community focused on synthesizing the large bandgap organic semiconductors, which were unsuitable for photovoltaic applications. Wide bandgap organic semiconductors can capture light only from the UV–Vis region of the solar spectrum, thus showing solar cells’ power conversion efficiency (PCE) of less than 5%. By reducing the bandgap, organic semiconductors can show good compatibility with the air mass (AM) of 1.5 solar spectrums. So, the attention came toward synthesizing low bandgap semiconductors, which led to the enhancement of PCE from 5% to 17%. This review summarizes the overall development of the last 15 years in the field of organic photovoltaic semiconductors. The significant parameters in organic semiconductors are their bandgap, the position of the highest occupied molecular orbital (HOMO), and the lowest unoccupied molecular orbital (LUMO) that can easily be tuned chemically by molecular designing. One of the issues in organic photovoltaic solar devices is the need for absorbers with a narrow bandgap to maximize power conversion efficiencies to a great extent. Moreover, several factors, such as conjugation length, bond length alteration, intermolecular interaction, donor–acceptor charge transfer, planarity, and physical states, are responsible for tuning the bandgap. This review also classifies low bandgap semiconductors based on the core skeleton with their bandgaps, structures, and power conversion efficiencies.

Introduction: The potential of zinc oxide (ZnO) and iron oxide (Fe₂O${}_3)$ nanoparticles (NPs) to induce toxic effects, especially genotoxicity, has been demonstrated in previous studies and is in part related to the ability of NPs to produce ROS. The use of antioxidants is an effective method to reduce NP-induced genotoxicity. The aim of this study was to determine the protective role of vitamin C as a potent antioxidant in ZnO-and Fe₂O₃ NP-induced genotoxicity in the HGF-1 cell line.

Methods: Different concentrations of ZnO and Fe₂O₃ NPs (50$\mu$g, 100$\mu$g, and 150$\mu$g/mL) were used to achieve the best concentration for further evaluation. HGF-1 cells were incubated with different concentrations of vitamin C 24h before the NPs. The cells were then exposed to ZnO and Fe₂O₃ NPs at a concentration of 100$\mu$g/mL for 1h. The possible genoprotective effects of vitamin C were determined using a comet assay.

Results: The results of this study showed that all concentrations of vitamin C could reduce the DNA damage induced by ZnO and Fe₂O₃ NPs.

Discussion: In conclusion, vitamin C could be considered a potent genoprotective agent against ZnO- and Fe₂O₃ NP-induced genotoxicity.

This research is devoted to the fabrication of zinc selenide nanostructures using the pulsed laser deposition (PLD) technique in a vacuum under a pressure of $2.5\times 10^{-2}$ mbar. The structure and structural properties were studied, as it was observed that it had polycrystalline structures and showed peaks for zinc and selenium and peaks belonging to the compound zinc selenide. As for the morphological characteristics of the nanostructures, the structures showed the nature of the surface and the roughness to identify its surface properties. Photocatalysis was carried out using several techniques (visible light, ultraviolet radiation and cold plasma), where a plasma jet system produced under normal atmospheric pressure was used in the treatment, with an exposure time of 4min and an argon gas flow rate of 3l/min. The hydrophilic properties were studied to apply these compositions in the self-cleaning process and photocatalytic activity. The results show that the ZnSe nanostructures have high wettability under UV light which has been shown to have excellent catalysis in the UV region, making its application as a self-cleaning material an attractive option.

In this paper, we investigate the influence of varying the thickness of noble metals, namely gold (Au), silver (Ag) and copper (Cu), and the incident light wavelength on the surface plasmon resonance (SPR) properties for biosensor applications. Our analysis employs the Fresnel equations to examine the absorption characteristics of these metals when the refractive index shifts by (0.03,0.06). We explore metal layer thicknesses ranging from $d=30\text{to}70$nm and incident light wavelengths of $\lambda =500$ and 600nm, with incident angles ($\theta$) ranging from 0° to 90°. Utilizing simulation analysis in MATLAB, we simulate the SPR responses of these metals when deposited on BK-7 glass prisms, with air as the surrounding medium. Our calculations reveal the absorption properties of Au, Ag and Cu, as indicated by the angle of incidence ($\theta$SPR). Our findings demonstrate that the highest absorption occurs with copper (Cu) at $A=0.999$ (a.u.) for $\lambda =500$nm and $d=30$nm. When $\lambda$ is adjusted to 600nm, gold (Au) exhibits the highest absorption (A) at 0.997 (a.u.) with a thickness of $d=40$nm. Additionally, we calculate sensitivity values for all three metals, with copper (Cu) yielding the highest sensitivity of 101.6 Reflected Index Units (RIU-1) for both $\lambda =500$ and 600nm. Furthermore, we compute the Figure Of Merit (FOM), with silver (Ag) achieving the highest FOM of 443 at $\lambda =500$nm and 451 at $\lambda =600$nm. These results provide important signs about noble metals’ SPR properties in biosensing, and serve as guides for optimizing the biosensors.

In this investigation, a spectroscopic optical emission test was used to investigate the characteristics of gold plasmas that were produced in the surrounding environment using an Nd: YAG system at a wavelength of 1064nm and had an energy output that varied from 400 to 600mJ. The emission spectrum profiles of (Au) were analyzed and recorded using a spectrometer to aid in the extraction of vital plasma features (i.e., $T_e$ and $n_e$). Plasma temperature was determined using the Boltzmann plot method, and electron density was determined using the Stark broadening method. The temperature was between (0.91 and 0.94)eV, while the electron density ranged between (4.79 and 5.26) $\times 10^{17}$cm${}^{-3}$. The rest of the plasma parameters were calculated by the mathematical equations of the method used (Boltzmann Plott).

This paper describes the synthesis of ZnO nanoparticles using air microplasma jets as the main reaction medium. Various techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and UV—Vis spectroscopy, were employed to confirm the characterization of the artificially synthesized ZnO nanoparticles. The absence of additional peaks associated with secondary phases of ZnO, as revealed by the XRD analysis, indicates the exceptional purity of these nanoparticles. Through the use of SEM, we examined the surface morphology and observed a substantial rate of agglomeration. The energy band gaps of ZnO nanoparticles were determined to be 3.3 electron volts (eV). The cytotoxic effects of zinc oxide nanoparticles were assessed using the methyl thiazolyl tetrazolium (MTT) assay on breast cancer cells exposed to various doses of the nanoparticles. The Acridine-Orange/Ethidium-bromide (AO/EB) dual stain was employed to assess apoptotic cells. The data indicate that ZnO NPs can induce apoptosis, suggesting their potential as an anticancer treatment in breast cancer cell lines. The presented findings indicate that nanoscale zinc oxide particles (ZnO NPs) possess significant potential for future utilization in many biological applications. An example of such an application could be the prospective substitution for chemotherapy in the management of various forms of cancer diseases.

In this study, the electronic and magnetic properties of hydrogen-passivated armchair and zigzag GaN nanoribbons are investigated using density-functional theory. We explore that doped TM atom leads to additional levels in the band gap and thus plays an essential role in spin polarization and changes their properties. Depending on its location in the nanoribbon, the character of spin-dependent electronic property of a doped GaN-NR was analyzed. Our calculations show that, regardless of the position of Mn atoms, GaNNTs are stable in ferromagnetic phase.

Nanotechnology has a significant impact on different fields such as medicine, information technology, energy, advanced materials, textiles, and many other new areas. In this study, the characterization of the green synthesized and chemically synthesized nanoparticle from Tribulis terrestris was studied. Yttrium nitrate hexahydrate was employed as a precursor material for the synthesis of nanoparticles. Characterization study was performed by using UV–Vis spectroscopy, FTIR, FE-SEM. For green synthesis, the peak was observed at 311nm while for chemically synthesized nanoparticles the maximum peak absorption was seen at 239nm. The FTIR analysis for green synthesized nanoparticles reveals the presence of three prominent peaks due to C–O stretching vibration, C–O bending vibration and Y–O vibration. Chemically synthesized nanoparticles show the presence of C–O stretching vibration, C–O bending vibration and OH-stretching. The results of SEM studies indicated the particle shape and size of chemically synthesized nanoparticles and green synthesized nanoparticles. Green synthesized Y₂O₃ NPs are an appropriate option for use in medicinal applications. Furthermore, detailed in vivo studies are needed to determine the safety and effectiveness of these green synthesized Y₂O₃ nanoparticles.

The study of physical properties of compound semiconductors plays a vital role in the device fabrication point of view. Different investigations suggest that one can tune these properties by impurity dopants, irradiation techniques, adopting different synthesis techniques, etc. In this study, the physical properties of nanostructured thin films of Se–S compound were tuned by different Hg dopant concentrations. X-ray diffraction spectra clarify the preferred crystallite growth occurs in the cubic phase of the corresponding Bravi’s crystal system. The particle size calculated from Bragg’s reflection spectra by using Scherrer’s analytical formula illustrates an enhancement of crystallite size in highly concentrated Hg-doped sample. Similar consequences are found in surface morphological micrographs. The optical band gap reduced from 1.65eV to 1.54eV on increasing the doping concentration of Hg, according to the computed optical parameters using optical transmission spectra in the wavelength range 200–1100nm. The thin-film refractive index dispersion data fits well in accordance with the single oscillator model. Investigation of electrical properties tells that there is significant improvement in electrical conductivity in highly concentrated Hg-doped samples. Therefore, the apparent tuning as observed in the physical properties of the investigated material may have practical uses in industry for a variety of optoelectronic devices.

This paper deals with propagation of Rayleigh-type waves in nonlocal inhomogeneous transversely isotropic half-space. From the characteristic equation of wave for the nonlocal inhomogeneous transversely isotropic medium, the existence of the number of surface waves depends on the inhomogeneity of the medium through the number of solutions satisfying the damping condition of the characteristic equation discussed. It has also been concluded that there exist cut-off frequency and escape frequency for the wave propagating in size-dependent materials based on the nonlocal theory. Dispersion equation for the propagation of Rayleigh-type surface waves at the free surface has been derived. Based on the obtained dispersion equation, the effects of the inhomogeneity of material and nonlocality parameter on the Rayleigh wave propagation are considered through some numerical examples.