Materials World Network: Collaborative Research: An Investigation into the Properties of B12As2, B4C and their Heterostructures

堪萨斯州立大学和纽约州立大学石溪分校的材料世界网络合作提案是研究富含硼的二十面体半导体B12As2和B4C在许多极端类别下的特性，包括高熔化温度、硬度、抗辐射损伤和塞贝克系数。这些性能的增强可以通过将这些材料组合在一起以产生复合异质结构来实现。本研究的主要目标是：(a)通过化学气相沉积控制化学计量和杂质浓度，开发能够生产单层和多层薄层材料的工艺条件；(b)确定薄膜中存在的晶体缺陷的类型和密度，以及由材料之间的界面引起的晶体缺陷；(c)研究基础半导体及其复合结构的电学、光学和热学性质。该奖项支持堪萨斯州立大学（薄膜生长），SUNY-SB（同步加速器，TEM表征）和布里斯托尔大学（拉曼，光学和椭偏振表征）在B12As2和B4C薄膜的合成及其随后使用一系列结构和光谱方法表征的合作。还将研究化学计量偏差的成分限制及其对机械和热性能的影响。在研究所之间的交流中，学生将学习材料合成和表征技术的能力和局限性，并从整体上欣赏他们在项目中的工作背景。该奖项支持的外展项目将以现有的努力为基础，为学生提供更好地接触材料研究的机会。本研究将建立这些硼化物半导体的加工、结构、组成和性能之间的关系，从而实现其在高温电子、热电子、辐射传感器等器件上的潜在应用。参与这项研究的学生将获得广泛而深入的教育经验，包括晶体生长，外延，材料表征和材料特性工程的基本方面。他们的教育经历将受益于相关研究所之间的交流访问、在国家实验室的实地考察、与该领域专家的互动、在专业会议上的研究报告以及向公众的报告。以英语为第二语言的中学生为对象，将开展新的教育推广活动。其目标是通过晶体生长和半导体应用的实践活动和演示来激发学生对科学和工程的兴趣。

This Materials World Network collaborative proposal from Kansas State University and State University of New York at Stony Brook is to study the properties of the boron-rich icosahedral semiconductors B12As2 and B4C lie at the extremes in many categories including high melting temperatures, hardness, resistance to radiation damage, and Seebeck coefficients. Enhancements of these properties may be realized by combining these materials together to create compositional heterostructures. The main objectives of this research are: (a) to develop process conditions capable of producing single and multiple thin layers combining both materials with controlled stoichiometry and impurity concentrations by chemical vapor deposition; (b) to identify the types and density of crystalline defects present in both the bulk of the thin films and those caused by interfaces between materials; and (c) to investigate the electrical, optical, and thermal properties of base semiconductors and their composite structures. This award supports collaboration between Kansas State University (film growth), SUNY-SB (synchrotron, TEM characterization) and Bristol University (Raman, optical and ellipsometric characterization) on the synthesis of films of B12As2 and B4C and their subsequent characterization using a range of structural and spectroscopic methods. The compositional limits to deviations from stoichiometry and their effects on the mechanical and thermal properties will also be studied. During exchanges between institutes, students will learn the capabilities and limitations of the materials synthesis and characterization techniques, and to appreciate the context of their work in the project as a whole. The outreach programs supported by this award will build on existing efforts and should offer opportunities for better exposure to materials research for students. This study will establish the relationship between the processing, structure, composition, and properties of these boride semiconductors, so their potential applications as high temperature electronics, thermo electronics, radiation sensors and other devices may be realized. The students involved in this research will receive an educational experience, which is both broad and in depth including fundamental aspects of crystal growth, epitaxy, materials characterization, and materials property engineering. Their educational experience will benefit from exchange visits between the institutes involved, fieldwork at national laboratories, and interactions with experts in this field, presentations of their research at professional meetings, and presentations to the general public. A new educational outreach program will be initiated for middle school students for which English is a second language. Its goal is to stimulate student interest in science and engineering through hands-on activities and demonstrations on crystal growth and the applications of semiconductors.