Comprehensive Microscopy Analysis of Au/Ag Nanoclusters on Silica Nanospheres

H. Qian, W. Shen, K. Cui, J. Cho, H. Fenniri
National Institute for Nanotechnology, CA

Keywords: TEM, tomography, HAADF, HRTEM, SERS

Summary:

we report a comprehensive structural and morphological analysis of gold (Au) / silver (Ag) nanocluster (shell) on silica (SiO2) nanosphere (core) with transmission electron microscopy (TEM) based techniques, including scanning transmission electron microscopy (STEM) tomography, high angle angular dark field (HAADF) imaging, energy dispersive X-ray (EDX), high resolution TEM (HRTEM) and nano beam diffraction (NBD). This comprehensive microscopy analysis not only characterizes the shape, structure, and composition of Au/Ag nanoparticles on the surface of SiO2 nanospheres but it also allows us to better understand the mechanisms and control the growth of Au/Ag alloy. As a result, significantly improved SERS properties could be achieved.