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

来自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为了研究富硼二十面体半导体B12As2和B4C的性质在许多类别中处于极端，包括高熔化温度、硬度、抗辐射损伤和Seebeck系数。这些性能的增强可以通过将这些材料组合在一起以创建成分异质结构来实现。这项研究的主要目标是：(A)开发能够结合化学气相沉积的化学计量比和杂质浓度的材料来生产单层和多层薄膜的工艺条件；(B)确定存在于薄膜块体中以及由材料之间的界面引起的晶体缺陷的类型和密度；以及(C)研究衬底半导体及其复合结构的电、光学和热性能。该奖项支持堪萨斯州立大学(薄膜生长)、SUNY-SB(同步加速器、透射电子显微镜表征)和布里斯托尔大学(拉曼、光学和椭偏表征)在合成B12As2和B4C薄膜以及随后使用一系列结构和光谱方法进行表征方面的合作。还将研究化学计量比偏差的成分限制及其对机械和热性能的影响。在学院之间的交流中，学生将学习材料合成和表征技术的能力和局限性，并欣赏他们在整个项目中的工作背景。该奖项支持的外展计划将建立在现有努力的基础上，并应为学生提供更好地接触材料研究的机会。这项研究将建立这些硼化物半导体的工艺、结构、成分和性能之间的关系，从而实现它们作为高温电子、热电子、辐射传感器和其他器件的潜在应用。参与这项研究的学生将获得广泛和深入的教育体验，包括晶体生长、外延、材料表征和材料性能工程的基本方面。他们的教育经验将受益于有关机构之间的交流访问、国家实验室的实地考察、与该领域专家的互动、在专业会议上介绍他们的研究以及向公众介绍。将启动一项新的教育推广计划，面向以英语为第二语言的中学生。它的目标是通过实践活动和关于晶体生长和半导体应用的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.