Nanoscale Structural, Plasmonic and Electronic Behavior using EELS and
Aberration Corrected STEM
Nanoscale heterogeneity is crucial for efficient coupling of electrical carriers to light and chemical energy. Therefore, detailed characterization of heterogeneity can teach us about how nano-structures function, so that more efficient operational principles, or cheaper, more abundant materials, can be brought to practical use in energy related structures. High energy resolution EELS in the microscope is a powerful tool for understanding nano-scale functionality because it is extremely sensitive to small, structurally driven changes that are relevant to electronic behavior -- carrier lifetime broadening, small confinement energy shifts, strain-induced energy level splitting, optical and plasmonic resonances, dependence on structural symmetries, to name a few. Modification of structures in the microscope is also possible, promising a more thorough exploration of the range of possible behaviors. It turns out that forces derived from plasmonic behavior can be used to manipulate nanoscale metal particles. These forces are derived from the same mechanisms that give rise to Surface Enhanced Raman Spectroscopy, and thus are closely related to optical-electronic interactions that are crucial to efficient photonic energy conversion. Therefore, through detailed analyses of the evolution of structural, plasmonic and electronic behavior in the microscope, we hope to obtain a broad view of nanoscale function which will be helpful to the future development of better energy-related applications.