硅熔体中Fe、Al、B、P组元热力学性质的模型计算与实验测定

发布时间：2018-05-14 17:16

本文选题：硅熔体 + 硼　；参考：《昆明理工大学》2015年硕士论文

【摘要】：太阳能以分布广泛、储量无穷、清洁可再生等优点备受世人关注。随着光伏产业的快速发展和太阳能电池使用的普及,作为太阳能电池基本材料的太阳能级多晶硅,占据了越来越多的市场需求。目前,价格昂贵的半导体级多晶硅广泛的用于太阳能光伏电池的制造是相当有限的。冶金法凭借成本低、投资少、建设周期短、相对污染小,被认为是提纯制备太阳能级多晶硅最经济和最直接的方法,但该新工艺的关键和难点是冶金级硅中杂质元素硼(B)的有效去除。因此,深入的研究硅熔体中杂质组元尤其是B的热力学性质,获得相关热力学数据对冶金法提纯过程的深入研究具有重要的研究价值。本文采用分子相互作用体积模型(MIVM),在1693-1873K的温度范围内,对二元硅基熔体中溶质组元的热力学性质进行模型计算研究,分别获得Si-Fe、Si-A1、Si-P和Si-B二元硅基熔体中Fe (500-3000ppmw)、A1 (500-3000ppmw)、P (1-100ppmw)和B (1-100ppmw)各组元的自身交互作用系数与温度的关系式以及各组元的活度和活度系数热力学数据,并与文献中报道的相关数据结果进行了对比,其结果较理想。充分说明采用该种方法获得各组元的自身交互作用系数结果的可靠性,也进一步验证了MIVM模型的有效性,为研究多元硅基熔体的热力学性质奠定基础。采用MIVM模型,在1693-1873K的温度范围内,对三元和四元硅基熔体中溶质组元的热力学性质进行模型计算研究,分别获得Si-Fe-B、Si-A1-B和Si-Fe-Al三元硅基熔体中B (10ppmw)、Fe (500-2500ppmw)和A1 (500-2500ppmw)各组元的活度以及Fe和Al对B的相互作用系数等热力学数据：以及在1873K温度下,Si-Fe-A1-B四元硅基熔体中A1 (500-1500ppmw）、Fe (500-2500ppmw)和B (10-50ppmw)的浓度范围内各组元的活度数据。此外,本文采用同一浓度(化学平衡法)和同一活度(溶解度法)的实验方法分别对Si-Fe-B和Si-A1-B三元硅基熔体热力学性质进行实验测定,获得样品在平衡状态下的溶解平衡组成,通过热力学推导和计算分别得到了1723K的温度条件下,Si-Fe-B和Si-A1-B三元硅基熔体中Fe对B的相互作用系数εBFe=86.4547和A1对B的相互作用系数εBAl=4.5906的结果。
[Abstract]:Solar energy is widely distributed, reserves infinite, clean and renewable and so on. With the rapid development of photovoltaic industry and the popularity of solar cell use, solar grade polysilicon, as the basic material of solar cells, has occupied more and more market demand. At present, the expensive semiconductor-grade polysilicon is widely used in the manufacture of solar photovoltaic cells. Metallurgical process is considered to be the most economical and direct method for purification and preparation of solar grade polysilicon because of its low cost, low investment, short construction period and relatively small pollution. However, the key and difficulty of the new process is the effective removal of boron B in metallurgical grade silicon. Therefore, it is of great value to study the thermodynamic properties of impurity components in silicon melt, especially the thermodynamic properties of B, and to obtain the relevant thermodynamic data for the further study of metallurgical purification process. In this paper, the thermodynamic properties of solute components in binary silicon-based melts are studied by using the molecular interaction volume model (MIVMN) in the temperature range of 1693-1873K. The autointeraction coefficients of Si-FeSi-A1Si-P and Si-B binary Si-based melts were obtained, and the thermodynamic data of their activity and activity coefficients were obtained, respectively, for each component of Si-FeSi-A1Si-P and Si-B binary silicon-based melts, and the autointeraction coefficients of each component were obtained, respectively, and the relationship between the autointeraction coefficients and temperature, and the thermodynamic data of the activity and activity coefficients of each component were obtained, respectively, for the components of Si-Feo Si-A1Si-P and Si-B binary silicon-based melts. The results are compared with the related data reported in the literature, and the results are satisfactory. The reliability of using this method to obtain the self-interaction coefficients of each component is fully explained, and the validity of MIVM model is further verified, which lays a foundation for studying the thermodynamic properties of multicomponent silicon-based melts. The thermodynamic properties of solute components in ternary and quaternary silicon-based melts were studied by MIVM model in the temperature range of 1693-1873K. The thermodynamic data of activity and interaction coefficient of Fe and Al in Si-Fe-B Si-A1-B and Si-Fe-Al ternary Si-based melts were obtained, respectively, and the concentration of Al _ 2O _ (500-1500) and B _ (10-50ppmw) in Si-Fe-A _ 1-B quaternary silicon-based melts at 1873K were obtained. The concentrations of Al _ 2O _ (500-1500) and B _ (10-50) mww) in Si-Fe-A _ 1-B quaternary silicon-based melts were obtained at 1873K, respectively, and the concentrations of Fe _ (500-2500ppmww) and B _ (10-50ppmww) in Si-Fe-A _ 1-B quaternary silicon-based melts at 1873K were obtained. Activity data of each group in the range of degrees. In addition, the thermodynamic properties of Si-Fe-B and Si-A1-B ternary silicon-based melts were determined by the same concentration (chemical equilibrium method) and the same activity (solubility method), respectively, and the equilibrium compositions of the samples in equilibrium state were obtained. By thermodynamic derivation and calculation, the results of Fe to B interaction coefficient 蔚 BFe=86.4547 and A1 to B interaction coefficient 蔚 BAl=4.5906 in Si-Fe-B and Si-A1-B ternary silicon-based melts at 1723K were obtained, respectively.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.2;TM914.4

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