| 초록 |
In surface enhanced Raman scattering (SERS), the formation and distributions of nanogaps in the ordered or disordered nanostructures are important. In this talk, a new PVD-based facile method to fabricate nanoporous structures with nanogaps will be introduced. Through a high-pressure thermal evaporation technique, highly 3-dimensional nanoporous structures of metals with the porosity exceeding 95% can be obtained. The nanostructures, whose formation mechanism can be explained by the diffusion-limited-aggregation, consist of loosely connected nanoparticle clusters. Due to the spherical morphology of the nanoparticles, enormous amount of nano-gaped regions are found, and these gaps are expected to be active sites of SERS. By applying this technique to metals such as Au, Ag, and Cu, which are known to be SERS-active, we can achieve much enhanced SERS signal compared to the commercial substrates for SERS. Moreover, these highly porous structures show black color absorbing most of the visible and near-IR of solar spectra. This absorbing characteristic enables the usage of various wavelengths of the laser for Raman scattering. |
