Improved seeded directional solidification process for producing high-efficiency multi-crystalline silicon ingots for solar cells

Growth Process Improvement for Casting High-Performance Multi-Crystalline Silicon Ingots for Solar Cells

“…Some shadow regions sometimes appeared in a silicon ingot, which definitely decreases the yield rate of silicon ingots [12,18]. In the original design, the shadow regions almost always appeared in the silicon bricks B11 and C13, as shown in Figs.…”

“…Many studies have shown that high thermal stress likely occurred in the central and edge regions of the silicon crystal [12,14,15], which indicated a W-type stress distribution in the crystal. A W-type stress distribution also occurred in the two designs.…”

“…Many new DS techniques have been developed for the seed-assisted growth for the High-performance (HP) mc-Si ingots [1,2], and the seeds consist of homo-seeds [3,4] or hetero-seeds [5,6] in the HP mc-Si industrial production. The quality of silicon ingots is significantly affected by the thermal history of the growth process, such as the evolution of the crystal-melt (c-m) interface shape [7,8], melt convection pattern [9,10] and thermal stress distribution [11,12]. To achieve the higher performance of HP mc-Si solar cells and market share, it is very necessary to optimize the DS process, including the furnace configurations and the process operating parameters in the industrial furnace.…”

Single-step directional solidification technology for solar grade polysilicon preparation

“…Firstly, the structure of furnace is symmetrical, so only a quarter of the geometry needs to be considered. Secondly, the convection in the growth system is weak and lacks a dominant heat transfer effect [14,15], so the convection in the silicon as well as in the furnace is ignored. The accurate calculation for thermal conduction, thermal radiation, phase change and thermal stress in the system are performed using the commercial software COMSOL Multiphysics, and the involved governing equations were described in our previous papers [16][17][18].…”