From mc-Si material made by cold crucible continuous pulling to solar cells

Multicrystalline-Si ingots were prepared by a cold crucible continuous pulling technique and 230 /spl mu/m thick wafers were cut using a wire saw. By means of mapping techniques such as light beam induced current, it is shown that the electrical properties of the wafers are homogeneous. Impurities have a tendency to aggregate in the form of quasi neutral precipitates and/or inclusions. Minority carrier diffusion lengths are relatively high in the grains: around 90 /spl mu/m due to a low recombination strength of extended defects. Conversely the recombination strength of grain boundaries is high. Solar cells made with this material lead to conversion efficiencies higher than 12%.