Femtosecond Laser Textured Surfaces for Radiative Cooling: Black Metals
There is a growing need for novel methods to modify the surfaces of a wide range of materials over large areas. Here, we demonstrate the creation of low-reflectance (R<2%) surfaces in the near-to-mid infrared (IR) spectral window of 2–20 μm by ablating W, Al, and Cu with high average intensity 20–120 TW/cm2, 200 fs laser pulses at 1030 nm wavelength. The chemical modifications of the surfaces by laser ablation under ambient room conditions were analyzed using X-ray photoelectron spectroscopy (XPS). The results show a consistent decrease in the metallic component, accompanied by an increase in metal oxides. Energy dispersive spectroscopy (EDS) showed a similar increase in oxygen content over a micrometer depth scale. The reduced refractive index of the metal oxides compared to the corresponding metals contributes to the reduction in IR reflectance, combined with the formation of 3D hierarchically textured surface structures. These IR-black metals exhibit great potential for radiative cooling at elevated temperatures relevant to industrial and space applications.
Authors
- Hsin‐Hui Huang (ORCID: https://orcid.org/0000-0001-6279-2291)
- Maciej Kretkowski (ORCID: https://orcid.org/0009-0003-3803-5161)
- Paul R. Stoddart (ORCID: https://orcid.org/0000-0003-4882-9400)
- Saulius Juodkazis (ORCID: https://orcid.org/0000-0003-3542-3874)
- Lina Grinevičiūtė (ORCID: https://orcid.org/0000-0001-8505-5067)
- Dong Mei Zhu (ORCID: https://orcid.org/0000-0003-4778-8918)
- Dominyka Stonytė (ORCID: https://orcid.org/0009-0005-3784-9520)
- Suresh Palanisamy (ORCID: https://orcid.org/0000-0003-1597-8696)
- Tomas A. Katkus (ORCID: https://orcid.org/0000-0001-5496-046X)
- Yoshiaki Nishijima (ORCID: https://orcid.org/0000-0003-0650-4536)
- Ričardas Buividas
- Nan Zheng (ORCID: https://orcid.org/0009-0003-4378-8088)
Institutions
- Tokyo Institute of Technology (JP)
- Shizuoka University (JP)
- Hamamatsu University (JP)
- Vilnius University (LT)
- Yokohama National University (JP)
- Center for Physical Sciences and Technology (LT)
- Vilnius University of Applied Sciences (LT)
- Innovative Research (United States) (US)
- Swinburne University of Technology (AU)
Publication Details
- Journal
- Applied Sciences
- Published
- 2025-02-16
- DOI
- https://doi.org/10.3390/app15042076
- Citations
- 6
- Primary Topic
- Thermal Radiation and Cooling Technologies
- Type
- article
- Field-Weighted Citation Impact
- 5.72
Funders
- Discovery Eye Foundation
- Swinburne University of Technology