Modeling of Crystal Growth
讲座名称：
Modeling of Crystal Growth
讲座时间：
2008-12-23
讲座人：
陈雪江
形式：
校区：
兴庆校区
实践学分：
讲座内容：
Simulations for two crystal growth systems will be presented: SiC growth by a physical vapor transport (PVT) technique and silicon growth with unidirectional solidification method.
For SiC growth process, it is necessary to well know the temperature distribution inside the crucible to grow a large crystal with a required interface shape and high quality, and to control the crystal growth rate. In the simulation system, the electromagnetic field, time averaged heat generation rate due to the induction heating, conductive heat transfer and radiative heat exchange, kinetics of physical vapor transport and thermal stresses were successively solved. Further, the effects of coils and shape of the crucible on growth system were investigated, and these results could help in better design of the growth system and effective control of the growth process.
Unidirectional solidification method is an important method for large-scale production of multi-crystalline silicon material for solar cells. The dislocations generated during the growth from the melt of crystals can greatly degrade the ingot quality for high efficient solar cell materials. The generation of dislocations is attributed to excessive thermal stresses inside the grown crystal. It is necessary to investigate the thermal stresses and dislocations in silicon ingot. In the simulation system, a transient global model was used to obtain the solution of thermal field within the entire furnace and thermal stresses in silicon ingot. Finally, the dislocation multiplication and stresses relaxation were also studied. Methods to reduce dislocations and stresses were suggested based on all simulation results.
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