Fundamentals of Heterogeneous Nucleation with Application to the Optimization of Horizontal Ribbon Growth

异质成核的基础及其在水平带生长优化中的应用

• 批准号: 2317674
• 负责人: Brian Helenbrook
• 金额: $ 55.41万
• 依托单位: Clarkson University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-11-01 至 2026-10-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2317674&HistoricalAwards=false
• 关键词: Fundamentals; Heterogeneous; Nucleation; Application; Optimization

This award supports research into new models of solidification kinetics and employs them to optimize the horizontal ribbon growth (HRG) process. HRG is a technique for producing thin wafers of single-crystal silicon for use in solar cells, which has the potential to significantly lower production costs (possibly 75% lower) compared to currently used techniques. Commercialization has not yet been successful mainly because of a lack of understanding of the solidification dynamics. New models enable the prediction of currently unexplained phenomena observed in HRG experiments. The models have the potential to impact crystal growth processes beyond HRG, leading to new applications with materials other than silicon such as sapphire or germanium. This work will provide deeper insights into the fundamentals of crystal growth and accelerate the development of new growth techniques, which will in turn help the US to achieve energy independence using renewable resources and grow advanced manufacturing in the US.Current theories for 2D Nucleation are derived assuming the nucleation occurs in a uniform environment with an infinite area, which always results in polynuclear growth. However, in all realistic growth processes, there are always temperature variations that limit the area where 2D nucleation will occur. The effect of these temperature variations will be investigated using Monte Carlo and Molecular Dynamic simulations, the results of which will be used to develop a new 2D nucleation model. This model will predict 2D nucleation and step propagation in spatially varying temperature fields without a-priori assuming polynuclear growth. This model will be incorporated into high-order accurate finite element simulations of the HRG process. These continuum simulations will predict the onset of 2D and 3D flow and solidification instabilities and their impact on the growth process. They will be used to optimize the process to enable the production of uniform, thin silicon wafers, at a high production rate.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.

该奖项支持对固化动力学新模型的研究，并采用它们来优化水平色带增长（HRG）过程。 HRG是一种用于在太阳能电池中生产单晶硅的薄晶片的技术，与当前使用的技术相比，它有可能显着降低生产成本（可能降低75％）。 商业化尚未成功，主要是因为缺乏对固化动力学的了解。 新模型可以预测HRG实验中观察到的当前无法解释的现象。 这些模型有可能影响HRG以外的晶体生长过程，从而导致除蓝宝石或锗等硅以外的材料以外的其他材料。 这项工作将为晶体增长的基本原理提供更深入的见解，并加速新的增长技术的发展，这反过来又有助于美国利用可再生资源并在美国发展高级制造业的能源独立性。2D核定的现成理论衍生而来，假设在统一的环境中会出现构成的环境，而始终是多工业的核心。 但是，在所有现实的生长过程中，总是有温度变化限制将发生2D成核的区域。 这些温度变化的效果将使用蒙特卡洛和分子动态模拟研究，其结果将用于开发新的2D成核模型。该模型将预测在空间变化的温度场中的2D成核和阶跃传播，而无需假设多核生长。 该模型将被合并到HRG过程的高阶准精确元素模拟中。 这些连续模拟将预测2D和3D流以及固化不稳定性的发作及其对增长过程的影响。 它们将用于优化该过程，以高生产速度生产统一的薄硅晶片。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估评估的评估值得支持的。