Analysis of material quality in multicrystalline silicon ingots

The objective of this work is to do a study of the material quality homogeneity in blocks of two industrial multicrystalline silicon ingots manufactured by Scanwafer, oriented to solar cell manufacture. Higher average of lifetime values has been observed in Ingot 2 due to improving and optimization of growth process. Moreover lateral and vertical variations of lifetime have been determined in both ingots. In addition, an analysis of the light induced degradation on the material is also performed. In both ingots, the interstitial oxygen [O_i] concentration, which is agent that causes the light induced degradation, is similar and this degradation is observed only in wafers from Ingot 2. An explanation is that this degradation can be measured only in ingot 2 because the quality of this second ingot is higher than the first one and there are not defects that dominate respect of the others.