热处理温度对铸造多晶硅棒切割性能与电性能的影响

Effects of Heat Treatment Temperature on Slicing and Electrical Performances of Casting Multi-crystalline Silicon Bricks

采用箱式气氛炉对铸造多晶硅棒进行热处理,研究了热处理温度对多晶硅方棒硬度、切割性能的影响。结果表明,经800、1000、1100℃热处理5h后多晶硅方棒硬度提高,而1150℃处理后,硬度开始下降,1200℃处理后硬度明显下降。经1200℃以上处理后多晶硅方棒切割性能优良,在使用金刚线切片机切割过程中,线痕、崩边、总厚度偏差(TTV)等现象明显得到改善。然而,经上述工艺热处理的多晶硅棒经常规工艺制成的电池片光电转换效率显著下降,这可能是热处理过程中气氛炉保温材料中的杂质元素扩散至方棒中,影响了电池的光电转换效率。

The effects of heat treatment temperature on the hardness and slicing performance of multi-crystalline silicon brick was investigated.The hardness of the samples treated at 800℃,1000℃and 1100℃is increased,while that of the samples treated at 1150℃is slightly decreased,and declined significantly at 1200℃.The slicing performance of bricks treated above 1200℃is desirable,and the defects such as saw mark,chipping,total thickness variation(TTV)occurred in the slicing process with diamond wire slicer are substantially improved.However,the photoelectric conversion efficiency of the battery piece made of multi-crystalline silicon brick by the conventional process after above-mentioned process is reduced significantly,which may be attributed to the diffusion of impurity elements into the brick during the heat treatment process,affecting the photoelectric conversion efficiency of the cell.