Characteristics of structural defects in the 240 kg silicon ingot grown by directional solidification process

Multi-crystalline silicon for solar cell over single crystalline silicon is its capability of using cheaper raw material. Since cheaper material contains harmful metal impurities, gettering technology has to be applied to silicon wafers to reduce the metal content in the crystal. Low dislocation density in the 240 kg multi-crystalline silicon crystal provides the strong possibility of gettering for the low cost silicon solar cell. Saw damage induced during the slicing process of multi-crystalline silicon ingot was confirmed to generate dislocation loops which can be employed for extrinsic gettering.