Horizontal Ribbon Growth of Single-Crystal Silicon

将太阳能转化为电能的高效太阳能电池的制造目前使用的是一种被称为Czochralski生长法的工艺来制造高质量的硅片。一种成本更低、效率更高的制造方法被称为水平带状生长，用于制造这些高质量的单晶硅片。与Czochralski生长法相比，水平带状生长法有潜力以更快的速度和更低的成本生产更薄、更大的晶圆，可节省高达75%的成本。然而，由于缺乏对控制这一过程的物理学的基本理解，水平带状生长过程的商业化一直很困难。该奖项支持的研究将贡献与制造单晶硅片的新工艺相关的新知识，称为水平带状生长。目前还没有模型可以预测在水平带状生长实验中观察到的所有现象。最重要的是，能达到的最高增长率还有待预测。这项工作的目标是建立一个过程的模型，可以预测实验观察到的现象，包括最大生长速率。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工业的发展，并将太阳能的成本降低到比任何其他能源都便宜的程度。此外，这项研究将有助于流体力学、热工程和材料科学领域的劳动力培训，并扩大未被充分代表的群体在工程研究中的参与。目前还没有能够准确预测水平带状生长过程的模型，而且发生的许多实验现象无法解释。开发一个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。由于水平带状的生长还没有被很好地理解或研究，所以在我们对凝固动力学的理解方面也有机会取得重大的基础进展。从分子到连续尺度的研究将用于理解和开发发生过程的预测模型。这种理解将被应用于优化工艺，也可能导致其他晶体制造工艺的改进。该奖项反映了美国国家科学基金会的法定使命，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.