Plasmon-enhanced photoluminescence and Raman spectroscopy of silver nanoparticles grown by solid state dewetting

The growth of the metallic nanoparticles (NPs) on the solid substrate with the desired shape and size is a critical issue for application of these NPs in solid-state devices. Solid state dewetting (SSD) technique is simple, low cost and can be used to fabricate the metallic NPs with control on the shape and size on different substrates. In this work, silver NPs (Ag NPs) were grown on corning glass substrate by SSD of silver precursor thin film deposited at different substrate temperatures by RF sputtering. The influence of the substrate temperature on the growth of Ag NPs and their several properties like localized surface plasmon resonance (LSPR), photoluminescence (PL), and Raman spectroscopy is studied. The size of the NPs was found to vary from 25 nm to 70 nm with the variation in substrate temperature from room temperature (RT) to400∘C. For the RT films, the LSPR peak position of Ag NPs is around 474 nm. A red shift in LSPR peak for films deposited at higher temperature is observed due to change in the particle size and interparticle separation. Photoluminescence spectra suggests the presence of two photoluminescence bands at 436 and 474 nm corresponding to Ag NPs radiative interband transition and LSPR band. An intense Raman peak was observed at 1587 cm^-1. Enhancement in PL peak intensity and Raman peak intensity is found to be in accordance with the LSPR of Ag NPs.