Gold nanoparticle array formation on dimpled Ta templates using pulsed laser-induced thin film dewetting

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Conventional thermal annealing for nanoparticle (NP) formation can deform substrates and is limited to low-melting-point metals.
• Pulsed laser-induced dewetting (PLiD) offers a potential alternative for controlled NP fabrication.

Purpose of the Study:

• To investigate the formation of gold nanoparticle (NP) arrays using pulsed laser-induced dewetting (PLiD) on dimpled tantalum (DT) substrates.
• To compare PLiD with conventional thermal dewetting in terms of substrate integrity, NP morphology, and potential applications.

Main Methods:

• Thin gold (Au) films were dewetted on nano-scale ordered dimpled tantalum (DT) surfaces using pulsed laser irradiation.
• The process was conducted in a high vacuum (low pO2) environment to prevent substrate oxidation.
• Characterization of the resulting Au nanoparticle arrays was performed, comparing them to samples produced via thermal dewetting.

Main Results:

• PLiD successfully produced high-quality gold nanoparticle (NP) arrays on DT surfaces.
• Unlike thermal dewetting, PLiD did not cause substrate deformation, even at temperatures above the gold melting point.
• PLiD-formed NPs exhibited a more spherical shape compared to those from thermal dewetting, indicating a different dewetting mechanism.
• The technique avoids thermal oxidation of the tantalum substrate.

Conclusions:

• PLiD is a viable method for fabricating high-quality nanoparticle arrays, particularly for high-melting-point metals like platinum, which are challenging with thermal methods.
• The laser-based approach preserves substrate integrity and offers control over NP morphology.
• Future work will explore the impact of NP size and shape on electrocatalytic properties.