Effect of Extended Gettering during the Emitter Formation on the Electrical Performance of Multicrystalline Silicon Based Solar Cells

Crystalline silicon (c-Si) wafers are widely used as precursor elements in solar cells manufacturing, and constitute more than 95% of the overall industrial market¹. The contamination of c-Si wafers, especially the multicrystalline one (mc-Si), by metallic impurities (Fe, Cr, Ni, etc.) is considered as a serious disadvantage. The presence of such impurities can drastically limit the efficiency potential of the solar cells.  Nevertheless, most metallic impurities can be partially removed from the whole bulk of the Si wafer, using gettering process. It refers to a thermal treatment step that activates the diffusion of interstitial impurities from the bulk of the wafer to less important superficial regions². In this present work we studied the impact of extended gettering on the electrical performance of Al-BSF solar cells fabricated in our center CRTSE by using mc-Si wafers of different initial qualities.