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The cluster-shaped plasmonic nanostructures are used to manage the incident light inside an ultra-thin silicon solar cell. Here we simulate spherical, conical, pyramidal, and cylindrical nanoparticles in a form of a cluster at the rear side of a thin silicon cell, using the finite difference time domain (FDTD) method. By calculating the optical absorption and hence the photocurrent, it is shown that the clustering of nanoparticles significantly improves them. The photocurrent enhancement is the result of the plasmonic effects of clustering the nanoparticles. For comparison, first a cell with a single nanoparticle at the rear side is evaluated. Then four smaller nanoparticles are put around it to make a cluster. The photocurrents of 20.478 mA/cm2, 23.186 mA/cm2, 21.427 mA/cm2, and 21.243 mA/cm2 are obtained for the cells using clustering conical, spherical, pyramidal, cylindrical NPs at the backside, respectively. These values are 13.987 mA/cm2, 16.901 mA/cm2, 16.507 mA/cm2, 17.926 mA/cm2 for the cell with one conical, spherical, pyramidal, cylindrical NPs at the backside, respectively. Therefore, clustering can significantly improve the photocurrents. Finally, the distribution of the electric field and the generation rate for the proposed structures are calculated.

The main aim of this research work is to significantly improve the photocurrent of an ultra-thin silicon solar cell. Here, cylindrical shape cascaded plasmonic nanoparticles are used to design an ultra-thin silicon solar cell. The main idea is to manipulate the absorption spectra of a thin absorber by applying four cascaded cylindrical shape nanoparticles from different materials with different radii and heights. At first, a cell with one nanoparticle at the surface and another one with a nanoparticle at the bottom side are simulated, and their photocurrents are determined. Then, a cell with four cascaded Ag, Al, Ag-Al, and Al-Ag nanoparticles is simulated. The maximum photocurrent density and efficiency of 23.46 mA cm−2 and 13.95%, respectively, are obtained for a cell in which Ag and Al’s nanoparticles are used alternatively from top to bottom. The photocurrent density is 8.2 mA cm−2 for a cell without any nanoparticles. The simulated results show that cascaded nanoparticles significantly enhance the photocurrent. Finally, the generation rate is presented at different wavelengths.

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By combining the global model for rf plasma discharge and the multi-component fluid model for the plasma-wall transition region, the effects of discharge conditions and reactor characteristics on the sheath and pre-sheaths of magnetized methane plasma are studied numerically. The global model determines the density of all species considered in the model as well as electron temperature for the given discharge conditions and reactor size, while the multi-component fluid model uses the parameters calculated by the global model to specify the distribution of potential and species densities in the transition region for a given magnetic field intensity and orientation. The results show that the transition region characteristics are affected by changing the discharge conditions and reactor size. As the sheath and the magnetized pre-sheath become narrower by increasing the input power and background gas pressure, their thicknesses increase with the increase in the electrode radius. Also, they become narrower by increasing the magnetic field intensity and the angle between the electric and magnetic fields.

The magneto-optical responses of a one-dimensional photonic crystal containing two magnetized plasma defect layers with operation in the millimeter wavelength region are studied by using a 4 × 4 transfer matrix method and full wave numerical simulation. The results of this study show that not only the values of the magneto-optical effects such as Kerr and Faraday rotations are tunable by the magnetic field and plasma layer parameters but also the positions of resonant modes in the frequency region are adjustable by these parameters. Also, it is found out that the repetition numbers of middle and surrounding unit cells in the structure can be considered to be other key factors for tuning the characteristics of resonant modes and magneto-optical responses related to them.

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