Inhibiting crystallization and enhanced non-wettability against molten Si of fused silica ceramic with addition of β-Si3N4

作者：Yang, Shaowen; Wang, Qinghu^*; Zhang, Xiaowei; Pan, Liping; Xu, Yibiao; Liang, Xiong; Li, Yawei; Yang, Zengchao; Li, Jiangtao

来源：Journal of Crystal Growth, 2023, 613: 127198.

DOI：10.1016/j.jcrysgro.2023.127198

• SiO2 composite ceramic
• Inhibiting crystallization behavior
• Contact angle
• Interfacial behavior

The main bottlenecks of fused silica crucibles for photovoltaic (PV) silicon growth are inevitable crystallization breakage and "ingot/crucible" adhesion, which hinders the improvement of quality and yield for silicon ingots. In this work, beta-Si3N4 was introduced into the fused silica system to obtain inhibited crystallization and nonwetting beta-Si3N4/SiO2 composite ceramic. The results indicate that the crystallization behavior was dramatically inhibited by introducing 20% wt% beta-Si3N4 into fused silica. After heated at 1550 degrees C for 30 min, the content of cristobalite in the beta-Si3N4/SiO2 composite ceramics was <7 wt%, which was 92.7% lower than that of pure fused silica. This can be attributed to the physical separation of the beta-Si3N4 component and the in-situ formation of O-Si-N chemical bond with higher binding energy. Simultaneously, the beta-Si3N4/SiO2 composite ceramics exhibited completely non-wetting characteristic with an average contact angle of 132.0 degrees against molten Si, which was attributed to the high micro-porosity of composite ceramics, in-situ formation of non-wetting SixNyO and the "pegging effect" of the notch at the "gas-liquid-solid" triple line. Furthermore, the Si/beta-Si3N4 transition layer exists stably at the "Si/substrate" interface to avoid adhesion, because of the low infiltration rate under the droplet.