Materials World Network: Detached Bridgman Growth of Semiconductor Crystals

这项工作是基于明尼苏达大学（UMN）和德国弗莱堡阿尔伯特-路德维希大学（ALU）的研究小组之间的合作。这项研究的重点是一种新的晶体生长技术，即分离布里奇曼过程，它起源于第一次太空实验室任务（1974年）期间进行的早期微重力实验。通过消除生长晶体与安瓿壁之间的有害相互作用，这种方法能够产生具有前所未有的结构完美水平的晶体；然而，分离凝固尚未在地球上可靠地实现。ALU的联合实验工作和UMN的理论研究将旨在使这一过程在陆地生长条件下可行。这个联合项目的一个重要部分是学生交流，这将培养研究生在晶体生长理论和实践方面的能力，并将为他们提供国际经验，鼓励他们成为未来全球材料研究界的领导者。这项活动将世界上两个最重要的晶体生长小组联合起来，利用他们强大的互补技能来实现分离凝固的实现和变革潜力。实验和理论将以互补的目标进行；UMN的努力带来了晶体生长建模工具和专业知识，以及明尼苏达超级计算研究所提供的重要计算资源，ALU的实验努力利用了他们对晶体生长的掌握和最先进的基础设施，以及10年在地球和太空中分离生长的经验。实现分离的布里奇曼工艺有望生产出质量迄今无法达到的大型单晶化合物半导体。最初的努力将集中在生产II-VI半导体碲化镉锌，这是一种高灵敏度辐射探测器所需的材料，对核不扩散应用和国家边界安全具有重要的战略意义。

This effort is based on collaboration between research groups at the University of Minnesota (UMN) and the Albert-Ludwigs-Universitaet (ALU) in Freiburg, Germany. The research focuses on a novel crystal growth technique, the Detached Bridgman process, that originated in early microgravity experiments conducted during the first Skylab missions (1974). By eliminating deleterious interactions between the growing crystal and the ampoule wall, this method is capable of producing crystals with unprecedented levels of structural perfection; however, detached solidification has not yet been reliably implemented on earth. The combined experimental work at ALU and theoretical research at UMN will aim to make this process viable under terrestrial growth conditions. An important part of this joint project focuses on student exchanges that will train graduate students in both crystal growth theory and practice and will provide them with international experiences that will encourage them to become leaders in the global materials research community of tomorrow.This activity teams two of the foremost crystal growth groups in the world to leverage their strongly complementary skills toward the realization and transformative potential of detached solidification. Experiments and theory will be conducted with complementary goals; the effort at UMN brings crystal growth modeling tools and expertise with significant computational resources available from the Minnesota Supercomputing Institute, and the ALU experimental effort leverages their mastery and state-of-the-art infrastructure for crystal growth, along with 10 years of experience with detached growth on earth and in space. Enabling the detached Bridgman process promises a means to produce large, single crystals of compound semiconductors with quality heretofore unattainable. Initial efforts will focus on growing the II-VI semiconductor cadmium zinc telluride, a material needed for high-sensitivity radiation detectors that are of great strategic importance for nuclear nonproliferation applications and securing national borders.