【摘要】 采用流化床反应技术,以H2还原SiHCl3的方法制备太阳能级多晶硅。在直径50 mm的流化床反应器中,加入多晶硅颗粒作为初始晶种,通入SiHCl3和H2气体使颗粒处于流态化状态;高温下,反应生成的多晶硅在晶种表面沉积令颗粒逐渐长大而获得颗粒多晶硅。实验考察了流化床反应状态下的硅还原率和硅沉积速率及其影响因素,分别在950～1100℃,H2/SiHCl3摩尔配比为15,20,30及晶种粒径为350,550μm的条件范围内进行实验。当加入晶种粒径为550μm时,在1100℃条件下,H2/SiHCl3摩尔配比从15%增加到30%,硅还原率从14.2%提高到21.6%;当H2/SiHCl3摩尔配比为20时,温度从950℃提高到1100℃,硅还原率从14.9%提高到19.4%。在1100℃,H2/Si-HCl3摩尔配比为30的条件下,当加入晶种粒径为350μm时,测得硅还原率为25.7%,硅沉积速率为21.3 g.h-1;而晶种粒径为550μm时,硅还原率为22.9%,硅沉积速率为18.0 g.h-1。实验结果表明:提高H2/SiHCl3摩尔配比、提高温度和减少晶种粒径均可显著提高硅还原率和沉积速率,适宜的工艺条件为1050～1100℃,H2/SiHCl3(摩尔比)20～30;晶种颗粒粒径和流化床气流速度是流化床反应过程主要的动力学因素。在西门子法中应用流化床技术将能显著提高硅的还原率和沉积速率,是制备太阳能级多晶硅的可行技术。更多还原

【Abstract】 Fluidized bed reaction was adopted to prepare solar-grade polysilicon by reducing SiHCl3 using H2.The silicon reduction ratio and deposition rate and their affecting factors were investigated,and the experiments were conducted separately.The experiment results showed that silicon reduction rate and deposition rate could be greatly improved by increasing the molar ratio of H2/SiHCl3,increasing temperature and decreasing the size of seed particles.The favorable technical conditions were temperature of 1050 to 1100 ℃ and H2/SiHCl3(molar ratio) of 20 to 30.The size of seed particle and the gas velocity of fluidized bed were the main kinetic factors during the fluidized bed reaction.In Siemens process,the application of fluidized bed technique could remarkably enhance silicon reduction rate and deposition rate,thus it was a feasible technique to prepare solar grade polysilicon.更多还原