Multicrystalline solar grade silicon solar cells from metallurgical process route and small Cz-Si test ingots have been investigated to further understand the impact of compensation and related reduced majority carrier mobilities. A possible PB complex which may prevent BO2i complex formation has been discussed recently by different research groups in several contributions. Our low temperature PL measurements strongly support the existence of such a boron/phosphorous complex. The industrially applicable multicrystalline crystallisation process at Elkem Solar as well as the solar cell process at ISC Konstanz were consequently further developed to improve the cell efficiency towards 17%.
