# Metal Nanodot Array via Thin Oil Layer‐Assisted Dropwise Solid‐State Dewetting

## TL;DR

A new method uses oil and surfactants to create uniform metal nanodot arrays, improving control over their size and shape for better performance in optical and electronic applications.

## Contribution

A novel fabrication strategy using thin oil layers and surfactants to stabilize metal surface energy during solid-state dewetting is introduced.

## Key findings

- The thin oil layer reduces metal surface energy and suppresses coalescence during dewetting.
- Nanodot size and shape can be controlled by adjusting deposition and oil layer thickness.
- The method allows fabrication of uniform arrays of single or multiple metals.

## Abstract

Precise control of metal nanodot arrays is crucial for optimizing their plasmonic, catalytic, and photonic properties. Fabrication methods for homogeneous nanodots generally rely on complex processes, such as lithography or layer‐by‐layer assembly. Recently, nanodot array fabrication via metal deposition, e.g., sputtering and thermal evaporation, has received attention due to its simplicity and scalability. However, structures produced by deposition are often inhomogeneous and suffer from size limitations, because metals generally possess high surface energy in air. In this study, we propose a strategy for fabricating uniform metal nanodot arrays through thin oil layer‐assisted solid‐state dewetting. Metals are deposited by sputtering onto a glass substrate coated with a thin oil layer, followed by thermal annealing that induces dewetting and the formation of nanodot. Surfactants incorporated in the oil reduce the surface energy of metals, thereby suppressing undesired coalescence. Additionally, the size and shape uniformity of the resulting nanodots are improved and can be controlled by adjusting deposition thickness and/or oil layer thickness. This simple strategy, based on surface stabilization using oil/surfactant, effectively overcomes the limitations of deposition methods. Furthermore, nanodot arrays composed of various metals, or two or more metals, can be fabricated, providing a versatile and customizable platform for nanostructure engineering.

A strategy is introduced to fabricate homogeneous metal nanodot arrays through solid‐state dewetting assisted by a thin oil/surfactant layer. The thin oil/surfactant layer effectively helps to reduce and stabilize the surface energy of metal, leading to controlled dewetting. This approach offers a customizable route to control nanostructure morphology and optical properties.© 2025 WILEY‐VCH GmbH