Effect of wettability on the bulk Si growth from Si–Sn melts via zone melting directional solidification

Abstract This work focused on the effects of wettability on bulk Si growth from Si–Sn melts during the zone melting directional solidification. The wettability behaviors of Sn/Si, Si–90 wt%Sn/SiO2, and Si/SiO2 were investigated along with the micro-morphology observation. The results showed that the surface roughness of the Si substrate and the growth temperature were essential factors influencing the wettability evolution. The reaction between Si and O formed SiO2 layer on the Si substrate, which could introduce a gap at relatively low temperatures, and the released SiO gas due to the reaction between Si and SiO2 caused the instant Si growth.