Novel Mono-Crystalline Solar Cells with Improved Efficiency
Abstract
Solar cells, as alternative energy sources, attract much attention in recent decades. Solar cells have the potential to replace fossil fuels as the main means of electric power generation. However, solar cells of all types suffer of two main deficiencies: relatively low efficiency, and high cost in comparison with conventional fossil fuel electric sources. It's known that the maximum theoretical efficiency of solar light to electricity conversion, may reach to approximately 93%. Also it's known that obtained solar power in earth is about 1.2u1017 W. Thus, there are significant reasons to put efforts and resources to develop low cost and high efficient PV convertors. The chart presented in figure 1 shows the best laboratory photovoltaic efficiencies obtained for various materials and technologies [1]. Usually, this is done for very small, 1 cm2, solar cells and requires application of concentrators, cooling systems, and complicated technologies such as multi-layer thin film semiconductor systems. These systems must take into account a variety of technological and material parameters such as: semiconductor lattice parameters, formation temperatures and working temperatures, refraction coefficients matching, thickness of all layers in the multi-layer system, concentration of charge carriers in the semiconductor layer, and many others.