Dr. Brillson has a broad research program in the structure and properties of electronic materials interfaces, emphasizing compound semiconductors for high speed microelectronic and optoelectronic device structures, wide band gap semiconductors for sensor and display applications, and thin film dielectrics for insulating gate structures. Understanding and control of such interfaces focuses on atomic-scale reaction and diffusion processes to control formation of localized electronic states, dipoles, Schottky barrier heights, and heterojunction band offsets. Experimental studies of electronic, chemical, and geometrical structure utilizing UV, X-ray, and soft x-ray photoemission spectroscopies, low energy (spatially-localized) cathodoluminescence and photoluminescence "buried interface" spectroscopies, Auger electron spectroscopy (AES) with sputter depth profiling, low energy electron diffraction (LEED), scanning tunneling microscopy (STM), Kelvin probe surface photovoltage spectroscopy, conventional device transport techniques, and in-situ chemical processing via directed energy beams. The scaling down of electronic device dimensions into the nanometer-scale regime emphasizes the need for first-principles, atomic-scale control of interface properties. Recent advances include the discovery of heterojunction band offset variations with local atomic movements near interfaces and the role of localized trap states in controlling charge transfer across nanoparticle contacts.