冶金法制备太阳能级多晶硅的除硼工艺及其控制机理研究
Research on Boron Removal Processes for the Production of Solar Grade Polycrystalline Silicon by Metallurgical Methods and Its Controlling Mechanism
摘要
硅作为全球半导体工业和光伏产业的基石，一直是太阳能电池的主要原材料。与传统的西门子法制备高纯硅相比，冶金法具有成本低、能耗小、安全环保等优点，因此，为适应太阳能电池产业迅速发展的需求，世界各国都在努力开发新的冶金法制备太阳能级多晶硅工艺。 硼作为硅的受主杂质，在太阳能电池基体中的含量不得高于0.3ppmw。由于硼具有较高的分凝系数和较低的饱和蒸汽压，难以通过传统的定向凝固和真空冶炼去除。本文围绕冶金法制备太阳能级多晶硅除硼的关键技术，开展了以下两方面的工作：首先，从湿法冶金工艺出发，通过熔盐电解精炼金属硅达到有效去除硼杂质的目的，对该方法的可行性和热动力学机理进行了研究；其次，从火法冶金工艺... As the foundation of the global semiconductor and photovoltaic industry, silicon is the main raw material for solar cell. To meet the needs of the rapid development of solar cell industry, all the countries in the world are working to develop new metallurgical methods for the production of solar grade polycrystalline silicon due to its low cost, low energy consumption, safety and environmental pro...