Toward viable horizontal ribbon growth of solar silicon: Understanding and ameliorating process instabilities

实现太阳能硅的可行水平带状生长：理解和改善工艺不稳定性

• 批准号: 1336164
• 负责人: Jeffrey Derby
• 金额: $ 31.86万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-10-01 至 2018-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1336164&HistoricalAwards=false
• 关键词: Toward; viable; horizontal; ribbon; growth

CBET 1336164DerbyThe development of renewable energy may be the most important challenge for the future of human civilization. Low-cost and reliable solar-to-electric conversion methods are especially important toward this endeavor. Of these methods, by far the most established technology is based on the fabrication of solar cells from crystalline silicon. However, significant reduction in the cost per watt produced by these technologies is needed to make solar energy competitive with fossil fuels. For silicon-based solar cells, production costs must be decreased while maintaining or improving cell efficiency. Advances in silicon growth methods are needed to achieve these objectives. Solar-grade, crystalline silicon is produced by a variety of techniques that melt and carefully re-solidify silicon via thermal processes. Methods that grow single crystals of silicon, such as the Czochralski process, are expensive, but such material achieves the highest cell efficiencies. Lower-cost growth methods, such as casting and vertical ribbon growth, have been developed, but their multi-crystalline material results in cells of lower efficiency. A promising crystal growth technology, known as the horizontal ribbon growth (HRG) process, was put forth in the late 1960's and was subsequently advanced in the late 1970's and early 1980's in Japan and in the U.S. After encouraging early results, experimental advances and process development efforts stalled, and this technique was abandoned by the mid-1980's in favor of more traditional methods that were easier to develop. Recently, however, there has been renewed interest in the HRG method, since, if successful, it promises a win-win scenario of significantly reduced production costs coupled with the ability to grow high-quality, single-crystal material. However, significant advances in the understanding and optimization of this growth method are needed to make it viable as a large-scale production process for silicon solar cells.This research is aimed at making the horizontal ribbon growth of silicon viable, particularly by addressing failure modes associated with its unique geometry and operation. Specifically, this project will apply sophisticated computational models of the horizontal ribbon growth method to elucidate and ameliorate known process instabilities and to study the salient issues associated with increasing growth rates to further reduce production costs. This research will apply a computation-centric approach to probe these issues and ultimately optimize growth conditions. Thus, this research will address fundamental scientific issues of crystal growth together with a clear goal toward improving a material with important technological applications.

CBET 1336164Derby Byter Byter Bythable可再生能源的发展可能是人类文明未来的最重要挑战。低成本和可靠的太阳能转换方法对于这一努力尤为重要。在这些方法中，到目前为止，最成熟的技术是基于从结晶硅制造太阳能电池的。但是，需要显着降低这些技术产生的每瓦成本，以使化石燃料具有太阳能竞争力。对于基于硅的太阳能电池，在维持或提高细胞效率的同时，必须降低生产成本。需要实现这些目标的硅生长方法的进步。 太阳级，结晶硅是由通过热过程融化和仔细重新固定硅的多种技术生产的。种植硅单晶的方法，例如牙齿的过程，很昂贵，但是这种材料可以达到最高的细胞效率。已经开发了较低成本的生长方法，例如铸造和垂直色带生长，但是它们的多结晶材料会导致效率较低的细胞。一种有希望的水晶增长技术，称为水平丝带生长（HRG）过程，于1960年代末提出，随后在1970年代末和1980年代末和1980年代初在日本和美国进步，在鼓励了早期的结果，实验进步和流程发展工作中停滞不前，这项技术因1980年中期而被更加传统方法而放弃了，从而倾向于开发这种技术。然而，最近，人们对HRG方法有了重新兴趣，因为如果成功，它将有望大大降低生产成本，并能够增强高质量，单晶材料的能力。 但是，需要在这种增长方法的理解和优化方面取得重大进展，以使其成为硅太阳能电池的大规模生产过程。这项研究旨在使硅的水平色带生长可行，尤其是通过解决与其独特的几何形状和操作相关的故障模式。具体而言，该项目将采用水平色带增长方法的复杂计算模型来阐明和改善已知的过程不稳定性，并研究与增长率提高相关的显着问题，以进一步降低生产成本。这项研究将采用以计算为中心的方法来探究这些问题并最终优化增长条件。因此，这项研究将解决晶体增长的基本科学问题，以及通过重要技术应用改善材料的明确目标。