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

该小型企业创新研究第一阶段项目提出了一种用于光伏 (PV) 行业一步硅片生产的创新方法。 直接从冶金级硅（MGSi）开始，建议使用熔融金属作为净化介质。 MGSi及其杂质将溶解在熔融金属中，通过杂质分配作用将杂质从MGSi中分离出来。 通过控制温度并利用密度差，可以将硅从熔池中分离出来。 一旦杂质被分离出来，硅片就会从熔池中取出。 这种一步法无需使用氯硅烷（通常用于生产多晶硅）。 此外，还消除了光伏行业的晶体生长和晶圆切片步骤。 该工艺将满足光伏行业生产廉价太阳能硅片的需求。该项目的第一阶段将集中于MGSi的纯化和表征方面的实验和理论研究。 这将导致一步晶圆制造系统的初步设计。 在第二阶段，详细研究将展示如何将这一单步过程简化为实践，从而在第三阶段实现商业化。该项目将为光伏（PV）行业带来一项基于美国的新技术。 所提出的技术可以大大降低光伏行业使用的硅片的成本。 预计通过这项技术，将有可能将太阳能发电的每瓦成本降低到太阳能发电可以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.