Ultra-wide bandgap semiconductors are candidate materials for next generation high power, high efficiency radio frequency applications. Among the most promising are AlN, Ga2O3, diamond, and cubic BN.  We have a great interest in developing and understanding the atomic structure of these materials. Primarily using aberration-corrected scanning-transmission electron microscopy (STEM), our objective is to provide nanoscale characterization of the phases, interfaces, and defect microstructure of epitaxial heterostructures, beginning with bulk materials and thin films. This work will primarily utilize a Nion UltraSTEM 200X at the U.S. Naval Research Laboratory, equipped with a wide-angle, windowless Bruker energy-dispersive X-ray spectrometer (EDS) and Gatan Enfinium electron energy-loss spectrometer (EELS) with a MerlinEM direct electron detector for high-sensitivity plasmon and core-loss EELS. This project will make heavy use of a Thermo Fischer Helios G3 focused ion beam (FIB) instrument and Fischione NanoMill to produce high-quality samples for analysis.

Hickman A. L., et al. (2021) Next generation electronics on the ultrawide-bandgap aluminum nitride platform. Semiconductor Science and Technology 36, 044001 (12pp).

Tsao J. Y. et al. (2018) Ultrawide-bandgap semiconductors: Research opportunities and challenges. Advanced Electronic Materials 4, 1600501.

key words

Transmission Electron Microscopy; Ultrawide Bandgap Semiconductors; Aluminum Nitride; Electron Energy Loss Spectroscopy; Functional Materials

Citizenship:  Open to U.S. citizens and permanent residents

Level:  Open to Postdoctoral applicants