Nargis Akter

Nowadays, solar photovoltaic (PV) is the most attractive and sustainable technology to solve the present power crisis. Indium Gallium Nitride (InGaN) is an amazing photovoltaic material that has tunable bandgap ranging from 0.7 eV - 3.4 eV that can cover the total solar spectrum to increase the efficiency abundantly. Recently, InGaN alloy is exhibiting its potential for various optoelectronic and power electronic applications. Such excellent semiconductor alloy from group III-V is motivating enormous research interest to build highly efficient photovoltaic cell. This paper works on the prospect of back contact materials by the performance of InGaN solar cells. The rigorous simulation was conducted with several ratios of In in InGaN with different thickness of P and N layer of the single junction solar cell. Different cell structures were examined through AMPS-1D simulator to discover the stable and efficient InGaN cell. Nine different cell structures were investigated to find the stable and efficient InGaN cell where Ti, Mo, Cu, Ni, Pt, Au, Co, Al, Ag, etc. were used as back contact materials and found a high conversion efficiency of 25.06%. Stability of the cell structure was also investigated that is -0.04/◦C shows the high stability.

With the advent of internet digital media has been improving with massive advancement in recent years. The distribution of unauthorized copies of media content has also been increasing day by day. Because of easy access to digital content, online purchasing and distribution becomes easier. Thus there is an urgent need to provide protection for digital content. One solution gaining popularity in protecting digital content is digital watermarking. In proposed scheme, a breadth-first search technique is used to find the efficient embedding point to embed the watermark. The proposed algorithm results show that the experiment offers better image quality and robustness under various attacks and alteration, such a, cropping, JPEG compression sharpening and filtering among others. The results have manifested the higher robustness and imperceptibility of this scheme when compared with other available watermarking techniques.