Effects of argon flow on heat transfer in a directional solidification process for silicon solar cells

Silicon Crystallization Technologies

“…During the process, the argon flow is in the range of 10-40 l/min and the pressure inside the furnace chamber is in the range of 500-800 mbar. The argon inlet contributes to the melt mixing quite significantly (Li et al, 2011(Li et al, , 2012b. The argon generates a cold spot in the center of the melt surface and triggers a strong surface tension-driven flow (Marangoni flow), which improves melt mixing substantially.…”

Effects of argon flow on melt convection and interface shape in a directional solidification process for an industrial-size solar silicon ingot

“…The algorithms for the global modeling of heat transfer in a DS furnace have been published in our previous papers [8,13]. The Boussinesq assumption and the low Mach approximation were applied to the melt and argon gas flows, respectively.…”

“…The temperature and velocity boundary conditions between the argon and the melt domains should be fully coupled to investigate the argon flow effect on the melt convection and the m-c interface shape. As the radial temperature distribution is not uniform at the melt surface due to gas cooling [8], the surface tension is considered. The coupled thermal and velocity boundary conditions at the m-g interface are:…”

“…It is found that a larger argon gas flow rate is beneficial for carrying away impurities from the melt free surface to get a higher-purity silicon ingot [6,7]. However, a large argon flow rate will cause big change in the melt flow pattern [8]. They also investigated the effects of furnace pressure on the argon flow pattern, which will further influence the melt convection.…”

Role of marangoni tension effects on the melt convection in directional solidification process for multi-crystalline silicon ingots

“…It has been considered in all investigations to date. The effect of gas shear stress on melt convection of the DS process has been studied by Li et al [7,10]. It was also widely investigated by many researchers for the Czochralski (CZ) silicon growth [11,12].…”