Efficiency evaluation of thin-film hetero-junction solar cells

Solar cells, as alternative energy sources, are attracting a great deal of attention during the last decades. Solar cells have the potential to replace fossil fuels as a main means of power generation. Solar cells technology is progressing rapidly. Solar cells may be fabricated from various materials and in various configurations. One of the enabling approaches to increase the conversion efficiency of solar cells is the multi-junction or hetero-junction configuration. These multi-junction or hetero-junction are most complicated structures, thus requiring a detailed analysis of their behavior before manufacturing, due to the high fabrication costs. In this work we describe an evaluation approach for the calculation of photovoltaic devices efficiency, for various structures, composing a solar cell. This evaluation method is based on rouge estimation of the charged carriers generation rate, for each step of the multi-junction system. This method was approved for the evaluation of hetero-junction system based on the ZnO-ZnSe-Si-Ge structure, and is compatible for various solar cell structures.