2010 Volume 45 Issue 1 Pages 3-8
The scanning transmission electron microscopy (STEM) laboratory in National Taiwan University represents the first dedicated electron energy-loss spectroscopy (EELS) group in Taiwan. Our major expenditure in the past five years has been the development of the conjunction of STEM and EELS, STEM-EELS, enabling an electronic characterization at nanometer-scale spatial resolution. Using this combined technique of STEM-EELS, we have unraveled the intriguing surface-plasmon properties in individual gold nanoparticles, popularly known as plasmonics, and revived a class of surface resonances, surface exciton polaritons that had been largely ignored in the past. As what we will discuss through this article, STEM-EELS is not only an indispensable tool for nano-characterizations, but also an avenue for unexpected physics.