局部氮化硅包覆颗粒在高效多晶硅铸锭中的应用

APPLICATION OF PARTIALLY Si_3N_4-COATED PARTICLES IN HIGHEFFICIENCE MULTI-CRYSTALLINE SILICON CAST INGOT

降低多晶硅晶体中的位错密度,可以提高多晶硅电池的性能,目前多采用异质形核的方法来生长柱状晶粒,以降低晶体中的位错密度,但是目前普遍采用的以SiO_2颗粒作为异质形核点的方法容易导致硅锭底部和坩埚粘连,并导致硅锭中间隙氧(O_i)含量升高。该文通过制备局部氮化硅包覆的SiC-Si O_2复合颗粒(PCP)作为异质形核点来生长柱状晶粒。结果显示采用适当粒径(300~500μm)的PCP具有较好的引晶效果,且对应硅锭的O_i含量显著降低。

Reducing the dislocation density of multi-crystalline silicon （mc-Si） crystal is an effective approach to improve the mc-Si cell performance. In the PV industry, SiO2 particles are commonly used as heterogeneous nucleuses to grow the high-performance （HP） mc-Si columnar grains, in which dislocation density is relatively low. However, SiO2 particles cause sticking between the ingot and crucible and increase the Oi concentration in the ingot. Therefore, it is necessary to develop new SiO2 composite particles results revealed that the seeding methods to grow Si ingots with the columnar grains. In this paper, partially coated SiC- （PCP） were prepared to replace the Si02 particles as heterogeneous nucleuses. The casting PCP with diameter 300-500 μm had good seeding effect and significantly reduced the Oi concentration in the ingot.