High Performance Solar Cells Exceeding 17% Efficiency Based on Low Cost Solar Grade Silicon

To further establish solar grade silicon from metallurgical process route in the photovoltaic market it is crucial to demonstrate the material quality by reaching high cell efficiencies and thus enabling SoG-Si to be competitive to “traditional” poly-Si. In this work we present Elkem Solar Silicon (ESSTM) based solar cells with efficiencies exceeding 17% demonstrating the high feedstock quality and a fine tuned solar cell process, which was optimized in respect to efficient gettering. Investigations of LID behavior of both ESSTM and poly-Si solar cells show even lower losses in cell efficiency on the SoG-Si material, which was confirmed by low interstitial oxygen concentrations measured using FTIR. Further experiments focused on improvements of the reverse current-voltage characteristics by applying different texturisation methods, which allow for similar cell efficiencies compared to the standard acidic iso-texturisation.