Nanoscale Structural, Plasmonic and Electronic Behavior using EELS and
Aberration Corrected STEM
P.E. Batson
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.