Self-assembly plasmonic gold nanoribbons on few-layer PtSe₂ under femtosecond laser irradiation

Functional two-dimensional (2D) materials have been extensively explored for a wide range of applications such as energy generation, low-power computing, and biosensing. In this work, we present an approach involving the integration of six-layer platinum diselenide (PtSe2) as an interlayer between the thin gold film and SiO2 substrate to induce spontaneous formation of plasmonic nanostructures (nanoribbons) on the upper gold film (similar to 8 nm) under 1030 nm femtosecond laser irradiation. The formation of periodic nanostructures is attributed to the periodic energy deposition that occurs in the PtSe2 layers under intense femtosecond laser pulses. Notably, the self-assembled gold nanostructures exhibit a distinctive polarization-dependent plasmonic response in the near-infrared spectral region and could be directly fabricated in a centimeter scale within several minutes. This straightforward method for self-assembling plasmonic nanostructures using layered materials may expand the utility of functional 2D materials and advance the cost-effective and large-area fabrication of plasmonic thin-film nanostructures in a simplified manner.