Horizontal Ribbon Growth of Single-Crystal Silicon

将太阳能转换成电能的高效太阳能电池的制造目前利用称为直拉生长工艺的工艺来制造高质量硅晶片。已经开发了一种用于制造这些高质量单晶硅晶片的更低成本、更有效的制造方法，称为水平带生长。与直拉生长相比，水平带生长具有以更快的速度和更低的成本生产更薄和更大的晶片的潜力，具有高达75%的潜在成本节约。然而，由于缺乏对控制该过程的物理学的基本理解，水平带生长过程的商业化一直是困难的。该奖项支持的研究，将有助于新的知识有关的一种新的工艺制造单晶硅晶圆称为水平带状生长。目前还没有模型的过程，预测所有的现象观察到的水平带状生长实验。最重要的是，可达到的最高增长率尚有待预测。这项工作的目标是开发一个模型的过程中，可以预测实验观察到的现象，包括最大的增长率。该模型将用于优化工艺，使其能够成功商业化。这有可能促进美国新产业的发展，并降低太阳能的成本，使太阳能比任何其他能源都便宜。此外，该研究还将有助于流体力学、热工程和材料科学领域的劳动力培训，并扩大代表性不足的群体在工程研究中的参与。目前还没有模型可以准确预测水平带状物的生长过程，并且有许多实验现象无法解释。开发预测模型将使人们更好地了解这一过程，从而减少商业化所需的时间和成本。由于水平带状生长没有得到很好的理解或研究，也有机会使我们的凝固动力学的理解显着的根本性进展。在分子连续尺度的研究将被用来理解和发展的过程发生的预测模型。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The manufacture of high efficiency solar cells to convert solar energy to electrical energy currently makes use of a process known as the Czochralski growth process to fabricate high quality silicon wafers. A lower-cost, more efficient manufacturing approach for manufacturing these high quality single-crystal silicon wafers, called horizontal ribbon growth, has been developed. Compared to Czochralski growth, horizontal ribbon growth has the potential to produce thinner and larger wafers at a faster rate and a lower cost, with up to 75% potential cost savings. Commercialization of the horizontal ribbon growth process has been difficult, however, due to a lack of fundamental understanding of the physics that control this process. This award supports research that will contribute new knowledge related to a novel process for manufacturing single-crystal silicon wafers called horizontal ribbon growth. There are currently no models of the process that predict all of the phenomena observed in horizontal ribbon growth experiments. Most importantly, the maximum growth rates attainable have yet to be predicted. The goal of this work is to develop a model of the process that can predict the experimentally observed phenomena including the maximum growth rates. This model will then be used optimize the process so that it can be successfully commercialized. This has the potential to promote the development of new U.S. industries and to bring down the cost of solar energy to the point that solar energy would be cheaper than any other energy source. In addition, this research will contribute to work force training in the areas of fluid mechanics, thermal engineering, and materials science as well as broaden the participation of underrepresented groups in engineering research.There are currently no models that can accurately predict the horizontal ribbon growth process, and there are many experimental phenomena that occur that are unexplained. Developing a predictive model will give a greater understanding of the process, which will reduce the time and costs needed for commercialization. Because horizontal ribbon growth is not well-understood or studied, there is also an opportunity to make significant fundamental advances in our understanding of solidification kinetics. Studies at molecular to continuum scales will be used to understand and develop predictive models of the processes occurring. This understanding will then be applied to optimize the process and could also lead improvements in other crystal manufacturing processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.