Giant enhancement of the initial SERS activity for plasmonic nanostructures via pyroelectric PMN-PT

Herein, a simply-prepared and highly sensitive electric field-induced surface-enhanced Raman spectroscopy (E-SERS) substrate is proposed by combining a pyroelectric material (PMN-PT) with the plasmonic silver nanoparticles (Ag NP). The intensity of SERS signals is further enhanced by more than 100 times after the application of positive or negative pyroelectric potentials. Theoretical calculations and experimental characterizations demonstrate that the chemical mechanism (CM) as induced by the charge transfer (CT) is mainly responsible for enhanced E-SERS. In addition, a novel nanocavity structure with PMN-PT/Ag/Al₂O₃/silver nanocubes (Ag NCs) was also introduced, which could effectively convert light energy into heat energy and realize a tremendous enhancement of SERS signals. These findings are expected to further accelerate the application of plasmonic metal nanoparticle-based pyroelectric materials in the fields of energy conversion, optical-sensors and photocatalysts.