Liquid-State Dewetting of Pulsed-Laser-Heated Nanoscale Metal Films and Other Geometries

Abstract

Metal films of nanoscale thickness, deposited on substrates and exposed to laser heating, provide systems that involve several interesting multiphysics effects. In addition to fluid mechanical aspects associated with a free boundary setup, other relevant physical effects include phase change, thermal flow, and liquid–solid interactions. Such films are challenging to model, in particular because inertial effects may be relevant, and large contact angles require care when considering the long-wave formulation. Applications of nanoscale metal films are numerous, and the materials science community is actively pursuing more complex setups involving templated films and substrates, bimetallic films and alloys, and a variety of elemental film geometries. The goal of this review is to discuss our current understanding of thin metal film systems, while also providing an overview of the challenges in this research area, which stands at the intersection of fluid mechanics, materials science, and thermal physics.

On efficient asymptotic modelling of thin films on thermally conductive substrates

“…(2016) for recent application-centred reviews, and Ruffino & Grimaldi (2019) and Kondic et al. (2020) for reviews focusing on molten metal film instabilities. Of late, PLiD has been used to organize nanoparticles into patterns of droplets via Rayleigh–Plateau-type instabilities (Favazza, Kalyanaraman & Sureshkumar 2006 a ; McKeown et al.…”

Nanoscale Soft Wetting Observed in Co/Sapphire during Pulsed Laser Irradiation

“…Recently, pulsed laser irradiation has been utilized to produce metal NPs through dewetting of a thin film [22,28,[34][35][36][37][38]. Pulsed lasers with pulse widths ranging from ns to fs can be used for laser induced self-assembly.…”

“…Thin films are momentarily heated above the melting temperature under a single ns laser pulse and melted into a liquid state, and then dewetted into nanostructures [22,34,39,40]. During the rapid cooling following the pulsed laser irradiation, the nanostructures solidify into various crystal structures where their phase diagram and kinetic limitations play key roles [34,35,39,41]. On the other hand, the morphology determined by the wetting kinematics, including liquid state surface tension and fluid dynamical effects, is typically preserved after rapid cooling.…”

“…On the other hand, the morphology determined by the wetting kinematics, including liquid state surface tension and fluid dynamical effects, is typically preserved after rapid cooling. Often, truncated spherical shaped NPs are observed after a number of pulsed laser irradiations [28,34,35,42]. In many cases, therefore, the final morphology of a metal NP after pulsed laser-induced dewetting (PLID) is deeply related to the behavior of a liquid metal nano-droplet on a substrate.…”

Multi-Purpose Nanovoid Array Plasmonic Sensor Produced by Direct Laser Patterning

“…Alternatively, utilisation of direct pulsed laser processing of plasmon-active materials (e.g., noble metal films) can be considered as a promising route for high-performing flexible and inexpensive mass production of various plasmonic nanostructures and their arrangements [11,12,13]. However, the interaction of ultra-short femtosecond (fs) laser pulses with the metal films is typically associated with the ejection and redeposition of multiple ablative nanoparticles precluding clean and highly-reproducible printing of nanostructure arrays supporting spectrally-narrow SP resonances.…”