MRI: Acquisition of a cathodoluminescence (CL) detector for nanoscale defect and impurity analysis in a shared-user facility

佐治亚理工学院(佐治亚理工学院)是美国国家科学基金会支持的东南纳米技术基础设施走廊(SENIC)的成员，该走廊是一项旨在促进纳米技术进步的倡议。这种专为纳米级研究级阴极发光探测器设计的探测器安装在佐治亚理工学院的共享用户分析设施中，学术研究人员、大小公司以及NSF支持的教育工作者和公众培训活动都可以使用。服务不足的少数族裔、女性和助理教授依靠这种工具来推动他们在纳米技术方面的进步。佐治亚理工学院以外使用该探测器的研究人员包括历史上的黑人大学克拉克亚特兰大大学的研究人员，以及佐治亚州大学系统的成员，即肯纳索州立大学、佐治亚大学和附近的佐治亚州立大学，后者是一家为少数族裔服务的机构。佐治亚州内的其他机构通过名为佐治亚州研究联盟核心交换的科学仪器共享项目访问探测器。与这一灵敏探测器相关的研究项目、学术课程、培训和外展练习为女性和少数族裔学生提供了掌握技术技能的机会。仅通过学术指导接触到这些技术的学生人数每年就远远超过100人。领导培训活动的首席调查员具有30多年对学生和研究人员进行实践培训的经验。当天然和合成半导体材料在高能电子轰击过程中发出光(发光)时，就会产生阴极发光。发射光的强度和波长可以用来测量半导体材料中缺陷的物理结构、化学成分和性质。当化学发光探测器连接到电子显微镜时，测量可以精确到纳米级(10^(-9)m)。这一新的方法可用于广泛的科学和工程应用，包括：1.确定宽带隙半导体(如GaN)的光学性质和缺陷结构，以改进半导体的制备和性能；2.优化用于微型化电子器件的陶瓷多晶材料(如碳化硅)的发光性能；3.测量辐射对地外物质的影响，以规划未来的空间探索；4.研究天然材料的结构和成分，以预测经济上关键的矿产资源的地球赋存，并改进地球的气候和构造模型。这一奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Georgia Institute of Technology (Georgia Tech) is a member of the NSF-supported Southeastern Nanotechnology Infrastructure Corridor (SENIC), an initiative for invigorating advances in nanotechnology. The designed-for-nanoscale research-grade cathodoluminescence detector is installed in a Georgia Tech shared-user analytical facility accessible to academic researchers, small and large companies, and NSF-supported training activities for educators and the public. Underserved minority, female, and assistant professors rely on this instrument, to further their advancements in nanotechnology. Researchers external to Georgia Tech employing the detector include those at Clark Atlanta University, a historically black university, and members of the University System of Georgia, namely Kennesaw State University, University of Georgia and nearby Georgia State University, a minority-serving institution. Other institutions within the state of Georgia access the detector through the scientific instrument-sharing project called the Georgia Research Alliance Core Exchange. The research projects, academic courses, training, and outreach exercises that tie in this sensitive detector provide opportunities for female and minority students to master technical skills. The number of students exposed to the techniques through academic instruction alone is well over 100 per year. The principal investigator leading the training activities has over 30 years’ experience with hands-on training of students and researchers. Cathodoluminescence (CL) occurs when natural and synthetic semiconducting materials emit light (luminescence) during high energy electron bombardment. The intensity and wavelength of the emitted light can be used to measure the physical structure, chemical composition, and nature of defects in a semiconducting material. When a CL detector is coupled to an electron microscope, measurements are possible down to the nanometer (10^(-9) m) scale. This novel approach is useful for a wide range of scientific and engineering applications, including: 1. determining the optical properties and defect structure of wide-bandgap semiconductors (e.g. GaN) for improving semiconductor fabrication and properties; 2. optimizing luminescence properties of ceramic polycrystalline materials (e.g. SiC) for miniaturizing electronic devices; 3. measuring the effects of radiation on extraterrestrial materials for the purpose of planning future space exploration, and 4. studying the structure and composition of natural materials for predicting the terrestrial occurrence of economically critical mineral resources, and refining climate and tectonic models of Earth.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.