Spatially Controlled Fabrication of Surface-Enhanced Raman Scattering Hot Spots through Photoinduced Dewetting of Silver Thin Films

• DOI: 10.1021/acs.jpclett.2c00403
• Publication Date: 2022-03-28T13:36:12Z
• Authors: Han-Kyu Choi; Sang-Min Park; Jeeyoon Jeong; Hankyul Lee; Gyu Jin Yeon; Dai-Sik Kim; Zee Hwan Kim
• Keywords: Dewetting

A well-designed narrow gap between noble metal nanostructures plays a prominent role in surface-enhanced Raman scattering (SERS) to concentrate electromagnetic fields at the local point, called "hot spot". However, SERS-active substrate fabrication remains substantial hurdle due high process cost and difficulty of engineering efficient plasmonic hot spots target area. In this study, we demonstrate simple photolithographic method for generating ultrasensitive SERS desired positions. The solid-state dewetting Ag thin film (thickness ∼10 nm) using continuous-wave laser (∼1 MW/cm2) generates closely packed assembly hemispherical nanoislands. Some these nanoislands provide plasmonic-field enhancement that is sufficient single-molecule detection plasmon-catalyzed chemical reaction. Such spot structures can be patterned on with spatial resolution better than 1 μm. integrated analytical devices, used as position-specific chemical-sensing elements.