Silver on nano-wrinkles as a substrate for surface-enhanced Raman scattering

Nano-wrinkles are used as a template to fabricate surface-enhanced Raman scattering (SERS) substrate. In the fabrication, micro-scale cylindrical pillars of photoresist are first prepared; a titanium (Ti) film is then sputtered onto the pillars, and the photoresist-Ti pillars are pyrolyzed, by which nano-wrinkles of the Ti film are produced; in the end, a silver film is sputtered onto the nano-wrinkles to obtain a SERS substrate. The enhancement factor of the SERS substrate and its uniformity are investigated. The effect of thickness of the silver film on the performance of the SERS substrate is discussed.