MSE Seminar: Leonard Brillson
Friday, September 8, 2017
1:00 p.m.-2:00 p.m.
2108 Chem-Nuc Building (090)
301 405 0876
Defect Characterization, Imaging, and Control in Wide Band Gap Semiconductors and Devices
Leonard J. Brillson
The Ohio State University, 205 Dreese Lab, 2015 Neil Ave., Columbus, OH 43210
Wide band gap semiconductors are now leading the way to new physical phenomena and device applications at nanoscale dimensions. The impact of defects on the electronic properties of these materials increases as their size decreases, motivating new techniques to characterize and begin to control these electronic states. Leading these advances have been the semiconductors ZnO, GaN, SiC, SrTiO3, and related materials. This talk will highlight the importance of native point defects in these semiconductors, then describe how a complement of spatially-localized surface science and spectroscopy techniques in three dimensions can characterize, image, and begin to control these electronic states at the nanoscale.
The interplay of multiple characterization techniques including depth-resolved cathodoluminescence spectroscopy and imaging reveals the importance of growth processes in controlling native point defects in wide band gap semiconductors and devices. These techniques can describe the nature and distribution of defects at interfaces at both bulk and nanoscale surfaces, their metal interfaces, and inside nanostructures themselves. We can measure these features as well as temperature and mechanical strain inside wide band gap device structures at the nanoscale – even while these devices are operating. These advanced capabilities enable several new directions for describing defects at the nanoscale, showing how they contribute to device degradation, and guiding growth processes to control them.