等离子提纯和电磁冷坩埚定向凝固太阳能级硅过程与硅锭质量相关性

项目名称： 等离子提纯和电磁冷坩埚定向凝固太阳能级硅过程与硅锭质量相关性

项目编号： No.51274076

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 矿业工程

项目作者： 陈瑞润

作者单位： 哈尔滨工业大学

项目金额： 78万元

中文摘要： 本项目研究等离子体提纯和冷坩埚定向凝固制备硅锭的工艺过程、硅锭质量和光伏性能，以及它们的相关性。通过控制混合气体比例、熔炼时间和熔炼温度等参数，利用等离子熔炼炉提纯多晶硅，得到这些工艺参数对硅提纯的影响规律，揭示等离子精炼脱杂机理。通过改变凝固速度、过热度、温度梯度等实验参数，制备不同的硅锭，系统研究电磁冷坩埚定向凝固硅锭时的熔化机理、熔体驼峰形成和特征；研究冷坩埚定向凝固硅的温度场、应力场和流场。研究硅锭中晶体生长过程中结晶界面控制原理；硅锭中晶体生长的热力学条件和动力学分析，液相流动对硅晶体生长的影响模型；研究生长硅锭过程中杂质分布规律和提纯原理，硅锭的晶体缺陷形成原理与控制，温度场与应力场与晶体缺陷的关系。等离子提纯效果与冷坩埚定向凝固效果的相关性。工艺过程对硅锭的电阻率、少子寿命和硅太阳电池转换率的影响机理。

中文关键词： 电磁冷坩埚；提纯；定向凝固；温度场；应力场

英文摘要： This project researches on the processing of plasma purifying and electromagnetic cold crucible directionally solidifying solar grade silicon ingot, the quality of the silicon ingot, photovoltaic performance and the relationships of them. The silicon was purified with plasma furnace by controlling the ratio of the mixing gases, the melting time and the melting temperature. Effects of the technical parameters on the purifying of silicon can be obtained, the mechanism of plasma purifying can be revealed. Different silicon ingots will be prepared under different experimental parameters, such as the solidification velocity, the superheat degree, the temperature gradient. The melting mechanism, the forming and the characteristic of the melt meniscus will be studied systematically. The temperature field, the stress field and the flow field during the process of electromagnetic cold crucible directional solidification will be measured and calculated. The theory of controlling the solid/liquid interface in the crystal growth will be investigated. The thermodynamics and the dynamics of the silicon crystal growth will be analyzed. The distribution of the impurities and purifying mechanism, the forming of crystal defects and measures to eliminate defects will be found. The relationships between the plasma purifying and col

英文关键词： electromagnetic cold crucible；purify；directional solidification；temperature field；stress feild