Optical Properties and Growth Aspects of Silver Nanoprisms Produced by a Highly Reproducible and Rapid Synthesis at Room Temperature

Abstract

A rapid and readily reproducible seed‐based method for the production of high quality silver nanoprisms in high yield is presented. The edge‐length and the position of the main plasmon resonance of the nanoprisms can be readily controlled through adjustment of reaction conditions. From UV‐vis spectra of solutions of the nanoprisms, the inhomogeneously broadened line width of the in‐plane dipole plasmon resonance is measured and trends in the extent of plasmon damping as a function of plasmon resonance energy and nanoprism size have been elucidated. In addition, an in‐depth analysis of the lamellar defect structure of silver nanoprisms is provided that confirms that the defects can lead to a transformation of the crystal structure in the vicinity of the defects. These defects can combine give rise to lamellar regions, thicker than 1 nm, that extend across the crystal, where the silver atoms are arranged in a continuous hexagonal‐close‐packed (hcp) structure. This hcp structure has a periodicity of 2.50 Å, thus explaining the 2.50 Å lattice fringes that are commonly observed in 〈111〉 oriented flat‐lying nanoprisms. A new understanding of the mechanisms behind anisotropic growth in silver nanoprisms is presented.