Imprintable Au-Based Thin-Film Metallic Glasses with Different Crystallinities for Surface-Enhanced Raman Scattering

The purpose of the present study was to fabricate a periodic nanostructure on Au-based thin-film metallic glasses (TFMGs) with different crystallinities for surface-enhanced Raman scattering (SERS) applications. To achieve this, fully amorphous Au-Cu-Si TFMGs were fabricated using magnetron co-sputtering, and thermal imprint was adopted to emboss the as-deposited film against a commercial anodic aluminum oxide template in the supercooled liquid region to develop the periodic nanostructure. For different crystallinities, the imprinted Au-Cu-Si TFMGs were heat treated at different temperatures. The morphology, crystallinity, dielectric properties, optical properties, and SERS effects were measured, and finite-difference time-domain simulations were performed to compare with the measured reflectance. It was found that Raman intensity decreased upon the initial crystallization of heat-treated amorphous film due to scattering at grain boundaries. However, the grain growth at higher heat treatment temperatures resulted in the reduction in grain boundary area, and the Raman intensity increased.

Automated summary

The study aimed to fabricate periodic nanostructures on Au-based TFMGs with different crystallinities for SERS applications. Results showed that Raman intensity increased with higher heat treatment temperatures due to reduced grain boundary area caused by grain growth.