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

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.