Shape effect on the optical properties of anisotropic silver nanocrystals

In this work, we have prepared three different shaped silver nanocrystals such as nanocubes, nanohexagons and nanohexapods with almost the same size by simple chemical reduction method, using PVP as a capping agent. These anisotropic silver nanocrystals have been characterized by UV-Visible spectroscopy, Transmission electron microscopy (TEM) and Photoluminescence spectroscopy (PL). From the TEM analysis, we have found that the particle sizes are 50 nm approximately for all these respective shapes. From the UV/Vis study, the surface plasmon resonance (SPR) peak positions are observed at 439 nm, 448 nm and 454 nm of wavelength respectively for nanocubes, nanohexagons and nanohexapods, showing that SPR peaks are shape dependent. Again, photoluminescence (PL) study also confirms that the emission peak positions are dependent on the shape of the anisotropic silver nanocrystals.