Nadia H Rafat

In this research we study the enhancement in power absorbance of thin film silicon solar cells by plasmonic yolk-shell (YS) nano particles. Plasmonic YS nano particles are simulated on top/bottom position of thin film Si layers. We suggest different structures of YS and simulate the behaviour of such structures using a FDTD simulations. We calculate the limiting photocurrent taking into consideration the enhanced absorbance of the cell. The simulation results show multi-peaked and broad band power absorbance enhancement all over the solar spectrum. The power absorbance enhanced into solar cell by 64% over planar ultra-thin 300 nm Si cell.

Perovskite is considered a very promising material in solar energy harvesting. Combining the advantages of Perovskite material and nanorod structure, Perovskite nanorod solar cell (PNSC) is believed to achieve a high conversion efficiency with low cost and simple fabrication processes. The rapid increasing efficiency of fabricated PNSC increases the demand for an efficient and accurate modeling that can simulate the parameters performance of the cell and estimate the important outputs. In this work, we simulate different structures of Perovskite nanorod solar cells namely; cylindrical rod, cone rod, inverted-cone rod, and modulated rod. The simulation is based on the finite element method. The material of the modeled cell is TiO2/CH3NH3PbI3 and we optimize the rod length, radius and spacing between rods for all structures to achieve the maximum conversion efficiency. The best efficiency is 18.6% for a cell of cylindrical rod of rod length, rod radius and rods spacing equal 400 nm, 5 nm and 65 nm, respectively.

The basic part of solar water heaters is the collector and the main functional part of the collector is the absorber layer. In this work, a commercial locally available black painting (PACEN code 10382 colour 890), used for swimming pools solar heating, was modified by adding nano-graphite dispersion. The effect of nano-graphite particles percentage on the spectral absorbance of the material was examined on samples containing two values of 1.5 and 2.5{%} nano-graphite particles by weight. Fourier transform spectroscopy (FTIR) analysisFourier transform spectroscopy (FTIR) was also used to identify the functional groups in the developed material. A simple experimental setup was designed to evaluate the performance of the developed nanodispersed selective coating polymeric based material, by measuring the increase in temperature of circulating water. It was shown that adding 1.5–2.5{%} nano-graphite particles to a polymer based black coating causes an increase in the optical absorptance, and an increase in the circulating water temperature.

Recently, photonic crystals have emerged to contribute in building all-optical computers and optical communication systems. This is due to the urgent need for faster computers and mobiles with high speed processing of data and with higher data transmission rates. In this paper we review the operation of photonic crystal logic gates and depict the different design techniques that produce a wide range of structures realizing the logic functions. We investigate several techniques such as self-collimated beam, multi-mode interference, interference based defect method and nonlinear Kerr materials based gates. As a summary, we compare the various key features of each design and illustrate the advantages and disadvantages of each design technique.