Hollow metallic pyramid plasmonic structures fabricated by direct laser writing and electron beam evaporation

Here we report a method that enables the fabrication of hollow metallic pyramid plasmonic structures on free-standing copper grids, which were fabricated by direct laser writing lithography followed by noble metal deposition. Gratings on the faces of these pyramids can translate incident light into plasmons that propagate toward the apex of the noble metal coated pyramids. Surface Enhanced Raman Scattering (SERS) measurements confirm that these hollow metallic pyramid structures have superior properties to the planar metal surface and the degree of enhancement can be tuned by the size and geometry of the fabricated structures, which potentially could be used for better understanding of surface enhanced plasmonics on free-standing three dimensional structures as well as find application in the research field of SERS.