SBIR Phase I: One-Step Silicon Wafer Manufacturing from Low-Grade Polysilicon for Photovoltaic Applications

这个小型企业创新研究第一阶段项目提出了一种用于光伏(PV)行业的一步法硅片生产的创新方法。直接从冶金级硅(MGSi)出发，提出用熔融金属作为净化介质。镁硅及其杂质会溶解在熔体中，通过杂质分配作用将杂质从镁硅中分离出来。通过控制温度，并利用密度的差异，硅可以从熔池中分离出来。一旦杂质被分离，硅片就会从熔池中抽出。这种一步法不需要使用氯硅烷(通常用于生产多晶硅)。此外，它还为光伏行业省去了晶体生长和硅片切割的步骤。这一工艺将满足光伏行业生产廉价太阳能晶片的需求。项目一期将集中于对镁硅的提纯和表征方面的实验和理论研究。这将导致一步晶片制造系统的初步设计。在第二阶段期间，详细的研究将展示如何将这一单步过程简化为实践，从而导致第三阶段的商业化。该项目将为光伏(PV)行业带来一种基于美国的新技术。这项拟议的技术可以大幅降低光伏行业使用的硅片的成本。预计有了这项技术，太阳能发电的成本/瓦特将有可能降低到与标准公用事业电力竞争的范围内。

This Small Business Innovation Research Phase I project proposes an innovative method for one-step silicon wafer production for the photovoltaic (PV) industry. Starting directly from metallurgical grade silicon (MGSi), it is proposed to use molten metal as the purification media. MGSi with its impurities will be dissolved in the molten metal, which will separate the impurities from MGSi through the impurity partitioning effect. By manipulating the temperature, and taking advantage of the density difference, silicon can be separated from the molten bath. Once the impurities are separated, silicon wafers will be drawn out from the molten bath. This one-step method eliminates the use of chlorosilanes (normally used to produce polysilicon). In addition, eliminates the steps of crystal growth and wafer slicing for the photovoltaic industry. This process will meet the demands of PV industry to produce inexpensive solar wafers.Phase I of the project will concentrate on the experimental and theoretical research for purification and characterization aspects of MGSi. This will lead to a preliminary design of a one-step wafer manufacturing system. During Phase II detailed research will demonstrate how this single step process can be reduced to practice, leading to commercialization in Phase III.This project will lead to a new US-based technology for the photovoltaic (PV) industry. The proposed technology can substantially reduce the cost of silicon wafers that the PV industry uses. It is expected that with this technique, it will be possible to decrease the cost/watt of solar power into the range in which solar power can become competitive with standard utility power.