摘要
采用喷涂法分别制备以α-Si_3N_4粉和β-Si_3N_4粉为原料的坩埚内壁用氮化硅涂层,进行烧结和多晶硅铸锭,利用扫描电子显微镜分析铸锭前后涂层形貌、X射线衍射分析仪分析铸锭前后涂层物相、少子寿命测试仪检测硅锭少子寿命以及红区长度等。结果表明:与α-Si_3N_4涂层相比,β-Si_3N_4涂层铸锭后高温稳定性强,与石英坩埚结合牢固,几乎无脱落现象。铸锭后α-Si_3N_4涂层颗粒呈类球形、竖直堆垛于坩埚表面,而β-Si_3N_4涂层颗粒呈六方短柱体、平行叠加于坩埚表面,恰好垂直于杂质扩散方向,故更有利于阻挡杂质的扩散。在不显著影响少子寿命的基础上,β-Si_3N_4涂层坩埚铸成的硅锭边缘红区更短、成品率更高。
Silicon nitride coatings used in the inner wall of the crucible are prepared by α-Si3N4 powder and β-Si3N4 powder with spraying method. The coatings are sintered and polycrystalline silicon ingot is cast. The coating morphology before and after ingot casting is observed by scanning electron microscope, the coating phases before and after ingot casting were analyzed by X-ray diffraction, minority carrier lifetime and the edge length of the red zone are detected by μ- PCD-micro wave photoconductivity. The results show that compared with α-Si3N4 coating, β-Si3N4 coating is stable under high temperature, which is tightly combined with quartz crucible and no coating brake off. After ingot casting, sintered coating with α-Si3N4 particles is spherical and stacked vertically on the crucible surface, but sintered coating with β-Si3N4 particles is hexagonal short cylinder and superposed parallel on the crucible surface. Because the superposed β-Si3N4 layer is perpendicular to the direction of impurity diffusion, the impurity diffusion is effectively blocked. Under the condition of no affecting the minority carrier lifetime significantly, the edge length of red zone is shorter in the silicon ingot prepared with β-Si3N4 coating crucible and the silicon ingot yield is much higher.
出处
《太阳能学报》
EI
CAS
CSCD
北大核心
2017年第12期3271-3275,共5页
Acta Energiae Solaris Sinica
基金
2014年河南省科技发展计划(142102210428)
关键词
β-Si3N4涂层
相转变
少子寿命
边缘红区
抗脱落性能
β-Si3N4 coating
phase transition
minority carrier lifetime
edge length of the red zone
spallation resistance
