Mohamed Ben Amar

A new method for improving performances of a polycrystalline solar cell

In this paper, we present a two-dimensional polycrystalline solar cell model to determine the parameters of the cell, such as the photocurrent, the dark current and the conversion efficiency. In this model, we consider an exponential doping profile of the p-region of the cell and hence the onset of an electric field in this region in order to reduce the minority carrier recombination at grain boundary and at rear contact. Consequently, this improved conversion efficiency of the cell. In order to optimize conversion efficiency, the presented model is implemented through a simulation program while varying thickness and doping concentration in the p-region of the cell. Compared with the case of Diracs function doping profile, the conversion efficiency is maximal in the case of an exponential doping profile.

Pressure and die temperature effects on microstructure and mechanical properties of squeeze casting 2017A wrought Al alloy

Squeeze casting process was carried out on an industrial 2017A aluminium alloy conventionally used for wrought products. In this research, the effects of applied pressure and die temperature on the microstructure and mechanical properties were investigated. The results show that the finer microstructure was achieved through the squeeze casting. Furthermore, higher pressures improved the fracture properties and decreased the percentage of porosity of the cast alloy. It was found that a direct squeeze casting pressure and die temperature gave a good combination of tensile strength, yield strength and elongation.