SGER: Epitaxial Electrodeposition for Large Area Single Crystals

技术：在许多薄膜应用中，单晶材料比多晶材料具有更好的性能。单晶中的长程有序、择优取向和晶界的缺乏显著地增强了许多应用的材料性能，例如光致发光、高温超导体和磁信息存储。然而，尽管有这些好处，但通常使用多晶膜，因为单晶衬底（如Si晶片）过于昂贵，面积有限或难以处理。为了使单晶衬底可用于更广泛的应用，PI计划开发一种方法，使独立的单晶衬底能够在大面积上廉价制造。该工艺基于电沉积和蚀刻步骤的顺序，其中牺牲层首先在起始单晶模板上外延电沉积，随后是较厚的最终层。然后从衬底和最终层之间选择性地蚀刻牺牲层，释放最终层并使衬底可用于再沉积。通过将初始基底形成为可以穿过顺序电化学电池的环，该方法可以扩展为用于连续形成无缝产品层的技术。在初步工作中，PI已经表明，电沉积和蚀刻可以用来制作独立单晶Ni的小样品;所得薄膜的结晶质量与初始模板一样好。然而，重要的研究是必要的，以了解和改善个人的蚀刻和沉积过程，并开发其他单组分和合金材料系统的等效能力。此外，必须克服科学和技术挑战，将这些步骤纳入一个持续的进程。非技术性：这项工作的更广泛影响将体现在对许多技术的影响上。作为私家侦探？随着加工方法的发展，PI将与工业界和学术界的合作者合作，探索使用我们的材料可以获得的改进。此外，该计划将教育研究生和本科生，无论是在电沉积和外延生长的科学，并通过让他们接触到许多技术，这种材料可以产生影响。

TECHNICAL: In many thin film applications, single crystals have much better performance than polycrystalline material. The long-range order, preferred orientation and lack of grain boundaries in single crystals significantly enhance material properties for many applications such as photovoltaics, high temperature superconductors and magnetic information storage. In spite of the benefits, however, polycrystalline films are often used because single crystal substrates (such as Si wafers) are prohibitively expensive, limited in area or difficult to work with. To make single crystal substrates available to a wider range of applications, PI plans to develop a method that will enable free-standing single crystal substrates to be fabricated inexpensively over large areas. The process is based on a sequence of electrodeposition and etching steps in which a sacrificial layer is first electrodeposited epitaxially on a starting single crystal template, followed by a thicker final layer. The sacrificial layer is then selectively etched from between the substrate and final layer, releasing the final layer and making the substrate available for re-deposition. By forming the initial substrate into a loop that can pass through sequential electrochemical cells, the process can be extended into a technique for continuous formation of a seamless product layer. In preliminary work, PI has shown that electrodeposition and etching can be used to make small samples of free-standing single crystal Ni; the resulting films have crystalline quality that is as good as the starting template. However, significant research is necessary to understand and improve the individual etching and deposition processes and to develop equivalent capabilities for other single component and alloy material systems. In addition, scientific and technological challenges must be overcome to integrate these steps into a continuous process. NON-TECHNICAL: The broader impact of this work will be in its effect on numerous technologies. As PI?s processing method develops, PI will work with collaborators in industry and academics to explore the improvements that can be gained by using our material. In addition, this program will educate graduate and undergraduate students, both in the science of electrodeposition and epitaxial growth and by exposing them to numerous technologies where this material can have an impact.