太阳能用晶体硅铸锭制备技术

在过去20年中,光伏市场以惊人的速度增长,光伏发电逐步成为世界能源发电的主要来源之一。2016年全球新增装机量超过75GW,较2015年增长34%,其中,又以晶体硅太阳能电池为主,占整个光伏市场的90%以上,而多晶硅又占据了整个晶体硅太阳能电池的70%以上。相比于直拉单晶硅,定向凝固铸造法生产的晶体硅材料具有更好的性价比,但含有较多的杂质、位错等晶体缺陷。更高品质、更低成本的太阳能电池始终是业界追寻的目标。本文以传统铸造法生长多晶硅技术为基础,介绍了目前几种主流的晶体硅铸造工艺方法,包括全熔工艺制备多晶硅锭,半熔工艺生长高效多晶硅锭,以及铸造法制备大尺寸单晶硅锭。另外,本文还从硅锭外观和性能等方面阐述了铸造法晶体硅的发展方向。文中数据部分为笔者进行的实验论证,部分为其他文献的研究成果,希望能为现阶段太阳能晶体硅的生产和研究工作提供参考。

The Preparation Technology of Crystalline Silicon Ingots for Solar Energy

In the past two decades, photovoltaic industry has grown at a dramatical rate, photovoltaic power generation is becoming a main source of electricity in the world. In 2016, the total amount of newly installed capacity in the world exceeded 75 GW, increased by 34% compared to 2015, crystalline silicon solar cells were accounted for over 90% of the pv market, and polysilicon accounted for more than 70% of crystalline silicon solar cells. Compared to Czochralski monocrystalline silicon, crystalline silicon produced by directional solidification casting method has better performance and lower cost, but it contains more impurities, dislocations and other crystal defects. Solar cells with better quality and lower cost are desired by the whole industry. In this paper, based on the traditional polycrystalline silicon ingot casting technology, common process of casting crystalline silicon was introduced, which includes the complete melting process of polycrystalline silicon ingot, semi-melting process of high efficiency polycrystalline silicon ingot, and the casting method to cast large-sized mono-like silicon ingot. In addition, the development of crystalline silicon with casting process is discussed in terms of its appearance and performance. The data in this paper partially were the experimental results by the author, reference of other papers were cited as part of the data to demonstrate the result of this paper. The author hopes to provide reference for the production and research of solar crystalline silicon at present.