Lithographically‐Fabricated SERS Substrates: Double Resonances, Nanogaps, and Beamed Emission

Abstract

Enhancement factors (EFs) and angular emission profiles of SERS from molecules on nanoparticles can be modified and optimized by engineering their surrounding environments, namely other nanoparticles, and dielectric and metal films. This chapter discusses structures that are termed “double resonance” SERS substrates. It is known that when SERS is performed with nanoparticles having a single plasmon resonance, maximum signals will be obtained when the resonance is situated between the laser and Stokes frequencies. Next, the chapter presents results from studies that demonstrate SERS substrates with double resonances, to enable strong intensity enhancements to be achieved at both the laser and..